In order to simulate the membrane effect in a structure in Advance Design, “DOF (Degree of freedom) constraint” object can be used with the Tx and Ty translations restrained. DOF constraint object is also named as Master-Slave connection. The command can be found in “Objects” ribbon tab:
The following properties regarding restraints definition are defined for the “DOF constraint” (Master-Slave connection):
For example, the response of the DOF constraint is compared with the response of a membrane in a simple 3D structure subjected to lateral loads. In this model, the elements’ self-weight is not considered.
Since the master-slave connection imposes to all component nodes the same DOF restraints (translations/rotations), the master node can be placed anywhere on the perimeter. In order to simulate the same response, the nodes must be placed on the same position as the mesh nodes of the membrane:
The similar response of the two objects (master slave connection with Tx and Ty translations restrained and membrane) can be verified by comparing the results of the FEM analysis:
BIM WORKFLOW WEEK is an online event organized by GRAITEC for structural engineers and detailers. Nowadays, you can streamline your BIM workflows using Graitec and Autodesk technologies together. Bridge the gap between all stakeholders and discover how you can develop and improve your construction projects in a digital thread!
Each day we will run a webinar to show how easy it is to streamline your daily work! We show how to apply a complete BIM workflow from design to detailing on all your projects during the webinars! Don’t wait and register today!
BIM WORKFLOW WEEK AGENDA:
Monday – 15/03/2021 – CREATE YOUR BIM MODELS WITH REVIT AND SIMULATE THEM WITH ADVANCE DESIGN
Are you a structural engineering company doing construction projects with Revit® from Autodesk in a BIM environment? In this webinar, we will propose you a way to streamline your projects, starting to CREATE BIM data in Revit, exporting it to Advance Design to SIMULATE your building and synchronize back in Revit all changes. Discover how easy it is to link Autodesk Revit and Graitec Advance design to simulate and optimize your steel an concrete projects.
Tuesday – 16/03/2021 – ENRICH YOUR 3D BIM REVIT MODEL WITH ANALYTICAL DATA AND RESULTS USING ADVANCE DESIGN
In this webinar, we will go deeper in the integration between Autodesk Revit and Advance Design: exchanging and synchronizing geometrical data is a good point but is not enough to enable a real BIM structural workflow. During this session, you will discover how to enrich your Revit model with finite element results and theoretical reinforcement values using Advance Design with an effective synchronisation mechanism controlled by the user!
Wednesday – 17/03/2021 – APPLY AN EFFECTIVE BIM WORKFLOW FOR ALL YOUR REBAR PROJECTS IN REVIT!
In this BIM era, it’s time for you to manage your rebar projects with 3D models using Autodesk Revit®! Join us to this webinar and discover how you can use the Autodesk platform and Advance Design together to produce 3D Design-driven rebar cages for Beams-Columns-Footings-Slabs-Walls & Shear Walls, automate the drawing views creation with all tags and annotations, produce final drawings and manage in real time all your rebar projects!
If you’re a structural engineer or a steel detailer using Advance Steel and want to save time, cost and reduce your carbon footprint, Graitec now offers a solution to complement and optimise your current workflow. To facilitate analysing these complex 3D steel connections, Advance Steel joints can now be exported to Graitec Advance Design Connection!
Friday – 19/03/2021 – APPLY A COMPLETE BIM WORKFLOWS FROM DESIGN TO DETAILING ON ALL YOUR STEEL PROJECTS!
In this webinar, we will go through a complete BIM workflow from design to detailing using Autodesk Advance Steel and Graitec Advance Design together. You will discover how easy it is to design and optimise a steel structure with Graitec Advance Design, including steel joints. Then, we will end by exporting the model to Advance steel to create drawings, BOM lists and CNC files fir the fabrication.
The shape optimization calculation for steel elements can be performed in Advance Design considering the condition of maximum deflection. Then, new cross-sections are searched if the deflection ratio is greater than the set limit (default 100%).
Thanks to this option from Advance Design, it is possible to optimize steel elements while using more criteria at the same time, like searching and selecting for profiles that must meet the conditions for maximum load capacity (strength/stability) and maximum deflection, independently or at the same time. This is especially useful for design of steel structural elements that exceed the maximum deflection while meeting the load capacity condition.
The optimization assumptions can be found in the Optimisation tab from Steel Design Calculation Assumptions dialog. Under the “Find new sections” paragraph, a new option is available to activate the deflection criterion and to set the maximum allowable deflection ratio considered for the cross section optimization. These assumptions apply to all steel members from the model which have Steelwork DeDefault optimization assumptionssign option from the element’s properties activated. The limits imposed in this tab apply to all cross sections as a group and cannot be applied differentially for singular element.
By default, the deflection ratio optimization is unchecked:
By checking the “if the max/all deflection ratio is greater than:” option, the user can impose the maximum ratio.
Once the steel calculation is completed, the strength/stability and deflection work ratios of steel elements are compared with the specific criterion, and other cross sections that meet the imposed conditions are suggested. The results of steel elements optimization are displayed in the Suggested shapes dialog, displaying the current strength/stability and deflection ratios. If the ratios are greater than the imposed limits (100% by default), the current ratio is displayed in red. For such cases, if the deflection criterion is activated, the next cross section from the catalog that will meet the required criterion will be suggested, displaying also the ratio for that section.
By opening the Accepted solutions flyout, we can select the suggested shape or other section from the same catalog.
After accepting the suggested (or imposed) sections, from the Accept all option, a new steel calculation is required, in order to recalculate the new sections and have correct results in the shape-sheet of the elements and reports. This optimization sequence is directly dependent with the sorting mode selected in the Sort profiles tab from steel Calculation assumptions. By default, the “Envelope criterion” option is selected, which means that the suggested profiles will meet both deflection criterion and strength/stability criterion.
If the Envelope criterion is selected, the new profiles are suggested from both cases, if the deflection or strength/stability criterion are exceeded:
If the Deflection criterion is selected, then the new profiles are suggested only if the deflection ratio is exceeded:
If the Strength/stability criterion is selected, then the new profiles are suggested only if the deflection ratio is exceeded:
In order for the deflection criterion based optimization to be computed, both Steelwork Design and Deflections options from element’s property list must be checked. The optimization based on deflection will be made according to the parameters introduced in the property list:
If the deflection verification is unchecked for an element, then “N/A” (Not available) message will be displayed for the Deflection work ratio in the Suggested shapes dialog.
This new feature makes result checking easier, thanks to the possibility of presenting a ratio for deflection during shape optimization. It also gives you the possibility to select optimal steel profiles considering the deflection. Various options from the Assumptions dialog help you get specific results for the steel elements used in design and enhance the workflow.
Recently this question came up from a colleague on how and where you find the Database entries behind the SDNF Export from Advance Steel. So, this is what is behind todays idea for the blog.
Within Advance Steel there are many different types of Export/import options, the core one of these is the SMLX options for transfer from Advance steel to Revit to Advance Steel, but sometimes over more traditional export formats are needed, in this case the SDNF format (Steel detailing neutral format) was being used to link to a Steel and piping software, the user was using Advance steel to complete their steel process but wishes to update within their piping platform. The simple answer is that the SDNF export uses the Databases called the GTC mapping, but which one, as there are two locations and then which tables, as there are several within the database. So, with this goal in mind, we looked into the actual database and more importantly which table and how the entries in the table are completed. The conclusions of this and approach is explained in the attached document link, but the summary is that for the export process the GTC mapping database, that is located under the Advance folder of Autodesk within your program files, is where you need to look and it is using the table called the ‘Profile Export conversions’, under the Advance Steel type. Also, the entries for the table can be created using the ‘Autodesk one to one mapping’ or can use the ‘expression format’ that is common within the database entries.
Advance Steel SDNF Export Mapping
Using Advance Steel 2021 version and the for the Export to SDNF option via the ribbon, we look at how to make a section group into the Export systems.
For the SDNF mapping the database is the GTC mapping.MDB database, this is found under the Advance\data folder of Autodesk within your program files.
Note: to see this you may have to enable hidden files and folders under the windows explorer options.
The data base is an Microsoft access database, the best way to edit this is with ‘Access’.
So the heading says which tables, for good reason, the system actually uses the Profile Export conversion table:
Although if you are creating entries via the mapping dialog that appears in the software, if it finds a beam type not mapped previously, in that case it creates two entries, with the other being in the GTC profile conversion. If you do create entries manually, you can go in and remove these, as they are not used.
How to find an entry in the table.
For the Access field , you can filter this down by checking the box under the column filter to show only those elements:
In this case just uncheck select all, then scroll the list and check for example HEB
You will see several listings for HEB, some with different GTC standard and export applications listed.
But actuall none of these may be any good to export exactly what you need. For example the line 1011 would look good for this export to SDNF, but trying this it is not doing what you would expect.
The issue is coming from the GTC standard, this does not have the correct reference that is aligned to the entry in the profile master table. That is the tynename text used in the profile master table, under the astorprofiles database.
The HEB reference is using the other table, and obsolete one.
The easiest way round this is to create a new table reference, to reflect the correct string and references, so you can either manually do this, or maybe just take a few sections and map them, and look for the entries in the DB table, they should start with prefix of 20000.
By mapping these manually, the GTC standard is created , so you can use this to form the string required.
If you have Excel this is an ideal platform in which to do this and create them and copy and paste back into Excel.
So, this is the simple way to create a line entry, then copy it out, then use the functions of Excel and expand the entries to cover all the sections from the profile table. This can take some time to create, but more importantly they add lots of entries to the main DB.
But there is another way to reduce this input.
Single line entry using Expressions
Within the GTC database, the user will notice there are entries, which appear to use a code abbreviation, a formula so to speak.
These expressions come from a format called regular expressions and there is some good information on this via this website link: ‘learn RegEx Experssion this website very useful, very good step by step tutorial. Take note there are many websites that explain this concept so feel free to google it and suggest others.’
This example the HEB beam mapping.
So from the previous entry in the profile export conversion table we can see the expression elements used in the line, so whilst in Access you can copy the line and paste it into Excel changing the key value to a more suitable entry, then comparing this to the manual lines, we can create a combined entry and paste it back into the Access table.
So with this line pasted back into the Access database, then close any open session of AS, close the access Database, Open the Profile export conversation table, then paste in the new entry, copied from excel.
Using this/ testing.
Create a simple model of the sections in question, then with new session of Advance steel open, run the process for using these new entries. Select the SDNF button and process the HEB thorough the new table entries. If this is understood correctly and we run the export and the Advance steel mapping is present the process should complete within out the need for one-by-one map process.
Checking the SDNF file format and naming etc, your notepad of notepad ++, you can view the file and see the names created in the listing.
All this from one line in a table, this is the process used, beyond the manual mapping of sections, it is also used for the Revit transfer of objects via the SMLX format, again using these expressions to map multiple entries. Please see the Autodesk University class that I had the privilege to present, over the Revit AS workflow, you see the same in this class for Revit and AS.
As a very common assumption for numeric models made In Revit, multispan beams are modelized as a series of colinear individual beams.
Thus, it’s make it easier for users to produce the formwork drawings, especially when placing beam tags which could include a mark number. This mark number (visible on the identity data in Revit Properties windows) could be set as unique per element, depending the codification rules of the project. It is possible to place the same value for several objects but in this case, the number indicated in the tag will be the same for all objects containing the same mark number.
In addition, for quantity take off, bill of materials trough Revit schedules, it is more practical and accurate to create several single beams for each span in Revit, rather than one single very long beam.
Graitec PowerPack propose through the Main bars command, a powerful wizard dedicated to reinforce structural elements such as columns, footing, walls or beams. This wizard proposes advance settings to define directly a full and complete 3D rebar cage instead of placing the bars one per one.
Nevertheless, to be reinforced as multispan beams, colinear beams should be consider as one, especially for the connection between to beams if we want to generate the appropriate reinforcement including a good management of the area connecting the two beams.
So, at this stage, users are often dealing with a dilemma between having on one hand a right formwork model composed of individual beams (enabling a good numbering identification for tags and good formwork quantities) and the other hand, having a long single beam for all the spans (which will be closer better to prepare the reinforcement part and not practical for the formwork model management).
To satisfy all requirements for having a good formwork model and a good model, compliancy with our tools to generate the appropriate rebar cage, Graitec PowerPack propose a specific command named MultiSpan Beam.
This command will create a specific shared parameter (named “G.Beam Continuity Group”) to all individual beams supposed to be part of the same multispan serie.
It will assign the same value for this shared parameter so that the Main bar command (dedicated to create the rebar cage) will understand that this group of beams as to be consider as one multispan beam. Users just have to launch the command and select the beam belonging to the same multispan serie.
Once the selection of beam is done and validated, we can see in the dialog box all the beams which are going to be group in a reinforcement point of view. The Mark Number is indicated as well, and it is still possible to adjust the selection by removing elements or adding new ones.
With this command, users could keep continue to model beams as individual beams and then, will be able to use our Main Bar command as a 3D rebar cage generator. The reinforcement of a selection of beams will be then consider as multispan. Main Bar will automatically detect the spans and users could switch to one span to another one, to define the reinforcement for each span individually.
With this command, the right reinforcement will be then generated for the extremities of the span and for each connections of the intermediate beams composing the span.
This notion could be also use for Graitec structural Design engine embedded in Revit, centralized in the ribbon PowerPack Design. The purpose of those tools is to launch design directly in Revit.
The command Geometryopen a dialog bow where each span corresponding to each individual beam are visible and recognized correctly by the software. Here, users could change section and control the geometry of each span without affecting and modifying the whole span. Thanks to this, after selecting just one beam and using the Calculate command from the PowerPack Design tab, the software will calculate the complete multispan beam with the adapted reinforcement assumptions and generate the full rebar cage.
Multispan Beam is a very practical command, easy to implement in your current workflow and which will really speed up the 3D rebar cage reinforcement generation based on your custom formwork model.
The present article explains how to determine wind loads on vaulted roofs at the Eurocode 1. Specifically, we will show how to use Figure 7.11 from EN1991-1-4, which provides the external pressure coefficients on vaulted roofs with rectangular base:
We will consider a structure with following dimensions:
f = 2,51m
h = 3,20m
d = 9,60m
The developed length of the vaulted roof will be split into 4 equal parts, for zone A, zone B (repeated twice) and zone C:
For each of these zones, the external pressure coefficient (Cpe10) is read on a graph, depending on the f/d and h/d ratios.
In our case:
f/d = 2,51 / 9,60 = 0,26
h/d = 3,20 / 9,60 = 0,33
For zone A
We start on the f/d axis until we reach the two diagrams related to zone A:
For h/d = 0, we read Cpe10,A = +0,42
For h/d ≥ 0,5, we read Cpe10,A = +0,16
We then perform a linear interpolation because in our case, 0 ≤ h/d ≤ 0,5:
For h/d = 0,33, we get: Cpe10,A = +0,25
For zone B
We start on the same position on f/d axis, but this time, we reach the zone B diagram.
We read: Cpe10,B = -0,96
For zone C
We read: Cpe10,C = -0,40
In the end:
For zone A => Cpe10,A = +0,25
For zone B => Cpe10,B = -0,96
For zone C => Cpe10,C = -0,40
Starting from version 2021, vaulted roofs at the Eurocode 1 are covered by the climatic generator of Advance Design.
Wind actions, whether 2D or 3D, are instantly generated:
As prescribed in the Eurocde 1, roof is divided into 4 equal zones.
The name of each zone as well as their Cpe value can even be displayed with a dedicated annotation:
The evaluation of wind action on vaulted roofs by reading the graph from the Eurocode 1 can be tedious, with a high risk of error.
Fortunately, in Advance Design, this process is fully automated. Wind forces are created instantly, and they can be updated in a single click whenever a modification is made on the building.
The calculated structure can be synchronised with the Revit input model; to do this you export the model from Graitrec’s structural analysis software, Advance Design, using BIM Connect. Then select the synchronisation option in Revit and indicate the location of the exported file. The software generates a list of all elements, creating a breakdown of added, changed and deleted elements.
After reviewing the changes that have occurred in relation to the calculation, you can accept, ignore or remove the changes from the sync list. Once the changes are accepted, the model in Autodesk Revit will update.
In Revit, using the PowerPack Design module, it is also possible to design foundations together with the calculation of the reinforcement, based on given conditions. After the calculations, reinforcement drawings can be generated automatically. Most of the drawing’s components such as sections, their location, used labels, dimension lines or lists/bar schedules can be saved by the user in a template which is a native Revit file. From this, PowerPack will generate the drawings.
It remains to define the steel connections. This can be done directly in Revit or using Dynamo, but for the sake of shop drawings, it is suggested to export the model to Advance Steel. The connection calculations themselves can be carried out in Advance Design structural analysis software, using the Steel Connection Designer module.
Monolithic floor slabs are currently one of the most popular solutions. Depending on the structural system used, they can cover relatively large spans.
In most cases, the slabs are reinforced with a two-way orthogonal grid up and down. A common misconception among designers is that the determination of the cross-sectional area of this reinforcement for the ultimate limit state is based solely on the bending moments which are the same for the directions of the reinforcement. Thus the dimensioning of the reinforcement in direction “x” would be based on the bending moment Myy and the reinforcement “y” on the moment Mxx.
The example of a simple two-span slab, in which one span operates in a decidedly unidirectional manner and the other in a bidirectional manner, shows how to determine the authoritative, dimensioning moments. The loads and geometry are not particularly relevant. We will mainly discuss the nature of the plate work without attaching importance to values. The model and calculations were made with Graitec Advance Design.
It must be remembered that the orthogonal reinforcement grid results from a certain compromise between its optimality from the load-bearing point of view and the ease of subsequent execution on site. In reality the directions of the principal moments can be and in many places are deviated from the direction of the moment Mxx or Myy. Therefore, the most optimal reinforcement would be one designed according to the trajectory and based on the values of the principal moments M1 and M2.
Remember that the values of the principal moments must be interpreted with their directions, since they are not local or global values of the structure. Where the principal directions coincide with the directions of our reinforcement, i.e. x and y, this means that the dimensioning value of the bending moment will be the moments Mxx and Myy and the trajectory of this reinforcement is the best possible.
It is easy to see that the directions of the principal moments coincide with the x/y direction in the central bands, but deviate at the corners. Most designers who have ever dimensioned slab reinforcement in more sophisticated FEA-based software have probably noticed that the reinforcement map does not correlate directly with the maps of orthogonal bending moments in the local floor system.
The “butterfly” shape of the two-way free-supporting slab and the top reinforcement of the corners in both the X and Y directions are very characteristic. This is usually the most questionable aspect for designers – after all, the bending moment maps in no way correspond to this distribution of reinforcement – but it is perfectly normal behaviour.
The devil is in the torsional moment Mxy/Myx. Its presence is responsible for the deviation of the moments from the x/y direction. In the main directions we are only talking about the moment M1 and M2, there is of course no torsional moment there. If you decide to deviate from the main trajectory and reinforce the slab with orthogonal mesh, you must take this moment into account in the dimensioning of the reinforcement. The program Advance Design does this automatically of course by determining the relevant dimensioning moment at each grid point. In short, this means the projection of the principal moments onto the reinforcement directions.
Influence of dimensioning forces on the dimensioning of reinforced concrete
When dimensioning reinforced concrete members, the program determines the dimensioning forces which the user can display on the structure at any time.
Literature on the principles of reinforcement design for reinforced concrete slabs recommended the use of bottom diagonal reinforcement in the corners of free-supported slabs with a certain cross-sectional area (most often referred to as maximum span reinforcement in this literature). Designers usually use such reinforcement, but often without being aware of the design necessity. It is important to realize that the above-designed orthogonal X/Y reinforcement taking into account the torsional moment closes the topic and we are not required to use any additional reinforcement with a trajectory separate from the orthogonal reinforcement. The fact remains, however, that orthogonal reinforcement is not fully optimal.
To illustrate this phenomenon, it has been decided to model in the corner a slab whose local directions (and thus also the directions of the reinforcement in the adopted settings) are in accordance with the directions of the principal moments.
When using orthogonal reinforcement, both top and bottom reinforcement in both X/Y directions were required. For trajectory reinforcement, a bottom reinforcement perpendicular to the bisector and an upper reinforcement parallel to the bisector is sufficient. This means that the principal moments are at this point deviated by 45º from the X/Y direction.
One of the most time-consuming stages during the design of reinforced concrete structures is the calculation and generation of documentation for elements such as beams or reinforced concrete columns. And usually, it is not about the complexity of calculations or difficulties in generating drawings, but rather a large number of such elements in each project. And as in practice, we use dedicated software for designing, and it is mainly on the capabilities of this software and the ability to use it that the efficiency of work depends.
In this short article, we will address one of the key issues to reduce work time, namely creating and using design templates in design modules of Advance Design. The mechanisms described below are available in all design modules, including RC Beam, RC Column, RC Wall, RC Footing and Steel Connection module.
Creating project templates with Advance Design modules is very simple and consists in saving the current settings from the current project to a file. To start with, we perform a full design process of an element (for example the first beam in the project), and as a result, all the required settings are already defined and tested. Then we call the command to save the template and enter a name for the template file. From now on, the same settings as in the current project can be applied to other similar elements.
Saving the new template is possible when we run the module for dimensioning in the standalone version (image above) as well as from the menu in Advance Design (image below). In both cases, the template is saved to the selected location on disk as a file.
Thanks to the fact that template creation is based on saving settings of the current task we can easily add new templates in every stage of work.
Generally, it is a good idea to prepare one or more general templates. We set parameters that we always want to use in all projects, like settings related to design codes, general reinforcement settings, range of reinforcing bar diameters used, etc. These will be starter templates, primarily used for the first element in a given project.
Then, while working with a given new project, it is usually useful to prepare several current templates, specific for that project. These may be templates with different settings related to the location of the element in the building (then they differ in settings like concrete cover, fire conditions, etc.), or templates related to geometry (for example separate for edge beams, T-beams, etc.), or with different settings related to reinforcement design (for example with other methods of constructing transverse reinforcement). It all depends on us.
It is important that when saving the template, all information is stored, including project settings, geometry, design parameters, reinforcement parameters or list of load cases and combinations.
But even more interesting is the fact that in Advance Design modules, when applying templates, we can decide on the scope of data that is loaded from the template. That means that when creating a new task based on a template, we can easily choose what to load from the template. Let’s see a simple example. We have saved a template for a multi-span T-beam with specific reinforcement settings, with defined specific list of load combinations, etc.
Next, we want to use this template to design another beam, but this time it will be a single-span beam with a different list of load cases while keeping all the other settings. To do this, when creating a new job, we can deselect the geometry and load settings when selecting a template:
The above method is useful, especially when creating new elements / subsequent beams in the standalone version of the program, when we enter all the data ourselves, including loads.
The approach is slightly different if we base on the FE model prepared in Advance Design and perform calculations in the design modules directly in Advance Design, or if we perform design calculations in stand-alone modules after exporting the element data to files. In this case, we are not defining the element from scratch because we already have the element with a defined geometry and internal forces, but we want to use our own templates to set all other parameters of the element. To do so, the template must be assigned to the element in Advance Design before sending it to the dimensioning module. This selection is made from the element properties in Advance Design.
Remember that the list of available templates then shows the names of template files located in the corresponding subdirectory on disk, which is different for each element category (beams, columns, walls, foundations or steel connections). All of these subdirectories are grouped into one master template directory in the User Folders of Advance Design’s design modules. The location of these directories is visible, for example, when saving templates.
So if you want to use different ranges of templates for different projects, it’s most convenient to simply archive/copy individual subdirectories or the entire main element template directory.
Of course, the use of project templates is basic but not the only way to increase the efficiency of the design process. Another way is to use your own drawing templates used by the Advance Design modules so that the time spent preparing and adjusting the reinforcement drawings is greatly reduced.
Another way is to optimize the workflow – for example, we can easily export the data for the design of reinforced concrete elements from Advance Design to files, separately for each element, and then distribute them to the individual team members. Then they can carry out the design and documentation process in parallel on separate computers using the stand-alone versions of the modules. In addition, the reinforcement files can be copied back into the project structure in Advance Design.
As well as calculating linear and non-linear statics, Advance Design can also perform what is commonly known as a buckling analysis. Buckling is the loss of stability of an element under axial compression force. As long as this force does not reach a certain critical value, the element will only shorten. Beyond this critical value, the element is thrown out of equilibrium, which is also called buckling. A structure can only be said to be stable if it can return to its original form after being tilted out of equilibrium.
The phenomenon of loss of stability in general is a rather complex issue. The linear buckling analysis itself, however, is quite easy to set up and carry out. It involves solving an eigenproblem that results in eigenvalues and eigenmodes. We will call the eigenvalue the critical multiplier and the eigenmodes simply the stability loss form. The force in an element multiplied by the critical multiplier is the critical force at which the element loses stability.
In simple cases (e.g. isolated elements), the critical force may be determined from Euler’s formula:
The designer must instead estimate the buckling length of the member, which is sometimes relatively easy. The forms of loss of stability and the buckling length for simple static schemes are generally known and are presented, for example, in EN 1992-1-1.
The problem starts to arise with unusually braced structures, where it is not so easy to estimate the rotational stiffness of the nodes. By solving a linear buckling analysis, it is possible to know the critical force and thus the buckling length.
Linear buckling analysis
The buckling analysis gives an answer to how close an element/structure is to losing its equilibrium state. If the critical factor is less than 1 (i.e. the load would have to be less than that currently occurring) the structure can practically be excluded from further calculations. The value of this multiplier if it is greater than 1 will give us information how sensitive the structure may be tosecond order effects and imperfections. This is mentioned in clause 5.2.1(3) of EN 1993-1-1, where it allows the use of 1st order analysis in calculations, provided that αcr > 10.
For a simple example of a cantilevered steel column (IPE400) 8.00m high loaded with a unit axial force, the results of the buckling analysis are presented below.
The first two forms of buckling are in the direction of the weaker axis of the section, the third in the stronger axis. The smallest critical factor is 106.68, assuming that the force was unit. That is, if the axial force was 106.68kN the column would buckle. Looking at the form of the loss of stability in each plane it is easy to see that the buckling length is 2*L – you can also ask the software for this figure – for evidence it will be determined using Euler’s formula.
An analogous check can be made in the second plane, the lowest coefficient of which corresponds to the third form of loss of stability. For a classic cantilever in both planes, 16.0m is expected in this case.
As you can see, buckling analysis is easy to carry out and accurate in simple cases. The case shown is as simple as possible, where the bar is subjected to axial, ideal compression.
The important thing to remember is that simple buckling analysis is fully linear – that is, both geometrically and material-wise. It is a very fast tool giving an answer in a short time about the potential behaviour of the structure, but it does not take into account 2nd order effects, and the material works elastically throughout.
In a situation where the whole structural system is analysed, and not just a separate element, the matter is somewhat more complicated – the critical factor, closely related to the form of loss of stability, should be identified with the elements that lose stability in this form. For a simple frame, analysed only in the plane of the system, 20 successive forms of loss of stability were obtained. The axial forces are shown below (only in members that are in compression, assuming that they do not lose stability in tension).
As shown in the image below, the 1st form of loss of stability is a global, canted form. The frame columns clearly lose stability in this form – the critical multiplier is 356.19, so with an axial force of 10.16kN, the critical force is 3618.89kN. Each subsequent form is responsible for the loss of stability of the compressed upper chord and the compressed posts and diagonals of the truss. The multiplication factors of these forms cannot, of course, be taken into account for the determination of the critical force and buckling length of the columns for example. Members that were not in compression in the buckling case do not lose stability.
With the advent of all kinds of computer methods supporting the work of the constructor, we began to design increasingly complex systems, whose work we could previously only estimate using various simplified, tabular methods, supported by analysis and research, but giving little room for manoeuvre in terms of geometry, load patterns, etc. The most popular method for the analysis of building structures is nowadays, and has been for many years, FEM, or Finite Element Method. When designing with such a system we can, to a large extent, model practically any object. This is easy for certain structures, but it should be remembered that the model is only a certain approximation of reality and will behave exactly as we have imposed it.
The FEM method relies on discretisation and takes into account any boundary conditions we ask for. Is the footing really a full restraint as we are used to modelling? Is a reinforced concrete beam really able to transmit the full moment according to the stiffness of the elements to a reinforced concrete wall? After all, it depends to a large extent on the solution of the reinforcement, on the solution of the steel connections, on the nature of the work… What we model for calculations we must try to reproduce as faithfully as possible in the detailed design – or vice versa.
Today, I would like to focus on the issue of stiffness of support elements, above all beams, and why this phenomenon must not be underestimated or whether we can somehow compensate for its lack of consideration. Using this example, I will also introduce the possibilities of Graitec Advance Design, which allows these problems to be dealt with automatically – it has tools for taking into account the actual stiffness in several ways.
Although slab-and-beam systems have somewhat given way to other systems, they are still used – if not fully, at least as a mixed system with another. In plate and column systems, it is sometimes necessary to use edge beams (for stiffening or to deal with shear punching in edge and corner columns) or transfer beams, in slab faults etc.
For the purposes of this article, a simple model of a residential building with services on the ground floor, with 6 overground storeys, founded on a foundation slab was prepared. 15cm thick slab in a slab-and-beam system on 25x50cm beams,. The whole structure is stiffened with a reinforced concrete communication shaft. We will consider the first residential storey, i.e., the floor above the ground floor. Loading by own weight, finishing and service category A.
The difficulty in this type of building in terms of modelling is to correctly account for the stiffness of the support members and their interaction with the floor slab. And this has to be taken into account in two ways. On the one hand, it is a modelling issue – the beams are modelled in the axis of the slab, but in reality they are subgrades/tensioners and their stiffness is actually much higher, often 2-3 times. On the other hand, in the case of reinforced concrete structures, for the purposes of statics, we analyse the structure in the elastic state taking into account only the stiffness of the uncracked concrete section. In fact, we should recognise what the stiffness will be with the actual reinforcement and scratching under this reinforcement. And here, exactly, there will be places where the stiffness decreases, but also places where it increases. It may not seem obvious that the beam in the second phase may be stiffer in some places, but there are places where the cross-sectional forces are close to 0, and yet we use there at least structural reinforcement.
I will try to discuss all these issues and how they are solved in Advance Design using the example of the building shown.
Displacements in the first phase of work are shown. It should be remembered that the building is elastically supported, so we cannot interpret these displacements directly as deflections. The whole building settles on the ground, additionally columns experience some deformations. The results are presented for a quasi-steady combination, as for this combination we will consider later the long-term effects in the outlined phase.
For the current model, no action has yet been taken to account in any way for the actual stiffness of the beams, either due to their position (slab uplift) or to the cracking (phase II).
Methods to consider stiffness of beams in FEM
Various methods, more or less faithful but also more or less labour-intensive, are commonly used to consider the stiffness of beams. For some time, designers used a tool built into most FEA programs, the offset – the physical offset of an element from its original position. But it is important to remember how this operation works. The beam is connected to the original nodes by rigid ties, which leads to the element working in a kind of “truss” fashion – the plate is the top chord, the beam offset under the plate is the bottom chord, and the rigid ties are the posts of our mental truss. This results in a reduction of the original moment and the introduction of longitudinal forces according to the principles of work, i.e. the slab begins to be in compression and the beam in tension. It is necessary to include all these forces in the model in some way, but we cannot directly size the beam in bending with tension. Tension would lead to a situation where the reinforcement in the span works both bottom and top, and we know very well from the nature of the beam work that the bottom reinforcement will be important for us in the span zone.
We would need to bring the condition into pure bending, and by using only an offset we are actually reducing the bending moment. We should reduce the forces in our “truss” by considering the action of the integral of the compressive force on the offset arm and include the moment from the effective part of the slab to size the beam. If we were to do this every time, in every beam and every section manually, and then manually size the beam, i.e. use simple calculators with our forces instead of using the forces from our model, we would conclude that using an offset is, in short, silly.
To illustrate this, we will also model the offset in Advance Design. The program has an automatic tool which will perform the whole process of force reduction to pure bending for offset beams for us – this option is called “Rib design” and I will talk about it later. Now, let’s focus on a simple offset and the nature of work of elements using it…something like this can be modelled in any FEA program.
Please note that the moments in the span have decreased from 170kNm to 115kNm. There is also a drastic tensile force of >700kN at these locations. An untrained designer could size the beam for the bending moment alone, which is significantly underestimated, or possibly incorrectly account for the tensile force.
Importantly, this method accurately represents the stiffness of the beams – the floor deflections in this situation are real. The problem is mainly due to the internal forces in the beam as proven.
Note – an offset can be modelled in Advance Design and not included in the FE at the same time. This is important in the age of BIM and exchange of models between different programs. In software for modeling building structures for design documentation purposes such as Revit we model beams in their real geometry. Advance Design will allow us to take into account the position of beams with offset, and it is the designer who decides if, and how, he will take it into account in FEM. This gives a great deal of freedom and goes a step further for designers working with BIM.
Another popular method, also fully operated by Advance Design, is to artificially increase the section inertia resulting from its actual displacement. The moment of inertia is best determined using Steiner’s Theorem, which in brief makes the moment of inertia dependent on the position of the centre of gravity relative to the axis for which it is calculated. What we want to achieve is easily described by the image below:
For the beam in the example it is 0.175m – this is also the offset value used above. The moment of inertia of the beam in the axis of the floor is 260416.66cm4, while that of the offset beam is 643429.16cm4. It follows that I need to increase the inertia of the modelled beam by 2.47 times.
In the 2020 version of Advance Design, the designer can define a factor to increase or decrease stiffness for both bending, compression/extension and torsion.
This method is simple, fast and produces correct results. The only thing that is not taken into account is the interaction of the beam with the slab over a certain distance, which the standard defines as the ‘effective width’.
Advance Design Advanced Tools
For one of the beams, I have defined the Rib Design option and specified the collaborative width of the slab. Please note its presentation- the beam is defined at the offset, but the slab is drawn into the collaboration. Note that this is an option to dimension a reinforced concrete element, not the FE model itself – the forces to be dimensioned will be determined as I said earlier (reducing longitudinal forces to bending).
The diagram on the right shows bending moments for a beam with a defined offset – this is very characteristic, the diagram is serrated due to the use of rigid connections in FEM nodes. As you can see, the dimensioning forces for reinforced concrete after the action of the rib design module have a classical shape – the values are correct. You can read more about how this tool works in the document “Advance Design 2016 – What’s new”, as this option has appeared in this version.
NOTE: Advance Design has also determined the stiffness in 2nd phase and the forces for the dimensioning take into account the section cracking. I show the stiffness distribution in the cracked member at the summary of the article below.
Please note that in the area of the highest moments (i.e. highest cracking) the section loses stiffness by almost 50%. At force levels close to zero, the stiffness increases – because the cross-section is not subjected to cracking and there is nevertheless continuous actual reinforcement.
I will try to talk more about the consideration of stiffness of reinforced concrete elements due to cracking on another occasion – today I tried to focus mainly on aspects of correct FEM modelling.
In this article, we will show you how to flip or rotate a section while keeping its local axes unchanged.
Why Would I Need That?
Flipping a section is often required when modelling.
For example, on the truss beam below, the Channel section defined on top member will not be left with its default orientation:
It will most certainly be flipped, using the ‘Angle’ property:
This will not only rotate the section but also its local axes:
This modification of member local axes can be a problem when working in a plane workspace, where several degrees of freedom are automatically disabled due to 2D simplifications:
Now, how can we define an in-plane rotational release when the corresponding degree-of-freedom (Rz) is not available?
Fortunately, there is no need to switch to a 3D workplane.
All you need is to flip the section without altering its local axes.
This can be achieved by adding the ‘S’ character at the end of section name.
This will rotate the section while keeping the in-plane bending about the y-y direction:
And because the Ry degree-of-freedom is still available, one can simply release it:
This article showed you how to orientate a member and define the required releases without necessarily switching to a complex 3D workplane.
This simple trick in section naming will let you benefit from all the advantages of a 2D analysis (short calculation time, easy result post-processing) while still getting the expected structural behaviour.
Temporary structures should not be designed with the characteristic values of wind velocity or velocity pressure from the Eurocode 1.
Indeed, these characteristic values are determined considering a return period of 50 years, which does not suit the provisional nature of such temporary constructions. Therefore, temporary structures will often be designed with a smaller return period than the usual 50 years.
Recommended return periods (n) are given in EN1991-1-6:
This return period value is then used to compute the probability factor (cprob) as per formula (4.2) from EN1991-1-4:
K is the shape parameter defined in the national appendix. The recommended value is K = 0,2
p = 1/n (with n being the return period, in years)
n is the exponent defined in the national appendix. The recommended value is n = 0,5
Be careful, in the cprob formula, n (the exponent) should not be mistaken with n (return period).
Of course, considering a 50-year return period in the above formula leads to cprob = 1,0.
Therefore, do not expect any benefit from the cprob factor for structures in use for more than a year:
Wind velocity for a return period of n years is then given by:2
Assume the case of a temporary structure in use from September to November (3 months) in a region where where characteristic wind velocity (for a return period of 50 years) is 24 m/s.
This temporary structure will be designed for a return period of 5 years:
The corresponding probability factor will be:
Resulting I the following wind velocity:
This results in a 15% reduction on wind velocity.
Advance Design results
Advance Design lets the user set the desired return period as well as the shape parameter and the probability exponent.
The corresponding wind velocity is then automatically computed:
Considering the appropriate return period when designing a temporary structure can lead to a significant reduction of wind velocity, thus scaling down the corresponding wind forces.
Not to mention the other parameters, such as the season factor cseason, that can diminish wind action even more.
When creating a design model for a structure, one of the steps is to prepare combinations for defined load cases. Most often we use the mechanism of automatic generation of combinations, according to the rules of the standard set in the project configuration. If necessary, we can modify the rules and relations between cases or case families using the available mechanisms in the Concomitance between load cases dialog window (available for Eurocode combinations).
However, while working on many projects there are situations when we want to define a set of our own combinations. Of course, in the case of a small number of load cases and a small number of required combinations, this can be done directly in the combination dialog. Nevertheless, in this article we will take a look at more effective methods, which will work especially well in case of a larger number of cases/combinations and when we want to use our own combination definition in other projects. These will be two solutions: using the mechanism to export and import combination definitions using an Excel spreadsheet and the mechanism to import combination definitions as a CBN text file.
Using an Excel spreadsheet
Starting with version 2020.1 Advance Design allows for easy and quick exchange of combination definitions between the current project and an Excel spreadsheet. For this purpose, there are two dedicated buttons available in the Combinations window.
The Export button exports definitions of all existing in the project load combinations to a new Microsoft Excel spreadsheet. For this a dedicated xlsx file is created on the path selected by the user. The Import button reads definitions of load combinations from the selected spreadsheet and adds them to existing definitions on the current project.
Let’s look at the data structure in the spreadsheet. The first row contains the column names, while the following rows contain the definitions of the subsequent combinations.
This column contains the identification numbers of the successive load combinations.
CODE and TYPE columns
These columns contain the combination type text code (CODE) as well as the name of the combination type (TYPE). The names and type codes depend on the settings of the project location – working language and standard for the load combinations. Below is an example of codes and types for the Eurocode settings:
It is important that when editing or creating a worksheet, the combination types in the TYPE column are consistent with the types available for the current standard. Therefore, in the TYPE column, the cell values are selected from the list.
CAS and COEFF columns
These columns are always defined in pairs and specify the load case ID number (CAS) and the corresponding coefficient (COEFF). The number of pairs of these columns’ headers should be equal to the maximum number of load cases in the most extended combination. Of course we can reduce or increase the number of pairs of headers if necessary. The number of pairs of values in a given row with the definition of the combination depends only on the given combination, but at least one value pair should be defined.
When you import load combination definitions from a selected spreadsheet, these combinations are added to the list of existing combinations in the current project. If combinations with the same ID number already exist in the project, then the ID number of the imported combinations is changed to the first free number. If the combination definition in the Excel file is incorrect (e.g. contains case numbers that do not exist in the model), then the combination is omitted during import. In these cases a warning appears.
Using the possibilities of a spreadsheet, including the possibility of using complex formulas, macros or cooperation with other programs, we have almost unlimited possibilities to prepare and automate the creation of our own load combinations.
Using CBN files
CBN files are text documents containing combination definitions. Generation of the predefined load combination with using the CBN file is based on loading the file from the disk using the Loads CBN button, located in the Combinations window. We can also preview the contents of the file without the generation of combination by using the View button.
To define your own file with the definition of a combination, you need to create a text file similar in structure to the predefined .cbn files. Lines starting with # or // are used to enter comments / notes and are optional. The remaining lines are treated as definitions of subsequent combinations and consist of case codes and coefficients separated by spaces. Additionally, at the end of each line there is space for the combination code and for the comment. Let’s look through the contents of the sample file:
In this example there are 3 lines of combinations, so 3 combinations will be generated. CASE1, CASE2, CASE3 are the type codes for 3 different load cases. Next to each code there are coefficients given with a character. Codes such as ECELUSTR are codes for the generated combinations. They can be arbitrary texts, in which case they will be used as an additional description, or they can be created in the naming convention for a given standard, so that they are automatically recognized as suitable combinations for design calculations. The text at the end of each line of a combination is optional and is not used during combination generation. It can be our additional description visible only during file preview. Note that in the last combination, in the second and third case coefficients equal to zero appear, which means that this combination will only contain the first load case. Exactly the same effect you get if there are no codes and coefficients for these two last load cases in this line. In the picture below you can see the effect of combination generation for the above example.
When loading the file, combinations are generated according to custom definitions, and the combination code is assigned to combinations accordingly. The combination name is generated based on the combination definition.
Note that when using an Excel file, to identify load cases their ID number is used. This allows you to precisely determine the relationship, regardless of the type of load case. However, in this solution we need to know the ID numbers of these cases before the combination is generated.
In case of CBN files, load case codes are used. Thanks to the codes it is easier to prepare a universal combination definition, which can then be used for many projects, but at the same time we have to be careful about the compatibility of the codes in the CBN file and in the project.
In every new project the load case codes are the same for all load cases. They can then either be modified manually by us or updated automatically by the program during combination generation (the program asks for this during combination generation).
Manual modification of the codes is useful when we have prepared the combination definitions in the CBN file using our own codes. In such a case, we can mark each case explicitly in a given project, making sure that they match the codes in the CBN file.
If you allow the program to automatically complete the codes during combination definition, remember that the same codes are assigned to all cases of a given type. This means that all fixed load cases will have the same code, similarly all snow load cases etc. This solution is convenient when there is no need to combine cases inside the same type.
Let’s see the effect of one exemplary row defining the combination in the CBM file:
CASE1 +1.10 CASE2 +1.20 CASE3 +1.30 CombA
Example 1. There are 3 different load cases with names and codes respectively: A – CASE1, B – CASE2 and C – CASE3. The result will be one combination with all cases:
A*1.1 + B*1.2 + C*1.3
Example 2. There are 2 different load cases with names and codes respectively: A – CASE1 and B – CASE2. The result will be one combination:
A*1.1 + B*1.2
Example 3. There are 3 different load cases with names and codes in the project: A – CASE1, B – CASE1 and C – CASE3. Note that the first two cases have the same code. The result will be two combinations:
A*1.1 + C*1.3
B*1.1 + C*1.3
As you can see both mechanisms, either using an Excel spreadsheet or using CNB text files, allow you to easily and quickly create your own sets of load case combinations in Advance Design. I encourage you to get closer to these solutions and use them while working with your own projects.
All modern design applications require a solid testing mechanism in order to detect any regression regarding the quality of the results but also to cover all areas of the application (GUI, CAD, correct workflows, …).
Advance Design has a mechanism based on a script that works like a batch session. This mechanism was mainly designed as a system for automatic tests to offer access to almost all areas in the application. In this way we can reproduce various scenarios.
Since it’s quite extensive and very cryptic, the main idea to use this mechanism is to start from a base script and adjusted or completed with the other commands. A base script can be generated by Advance Design. Usually an automatic test in our QA system consist in a model and a script. Both are passed to Advance Design in command line and the application executes the script.
In the following points we will go into details for such scenarios.
The base model creation
The first step consists in creating a model using your preferred localization and norms. The creation of load cases and their configuration is also recommended.
The analysis hypothesis, options for concrete analysis, steel analysis, etc. can also be configured at this step. Then, after saving the model, a back-up is recommended because it will be needed at a later step.
Until now we could say we have a complete environment. From this point we can start generating the structure elements (linear elements, planar elements, footings….).
2. The elements creation through scripting
2.1. Commands syntax and script composition
The syntax of a command that creates an element with geometry is composed by:
the_name_of_the_command+space+(x_coordinate;y_coordinate;z_coordinate)[and repeat the ’+ space+(x_coordinate;y_coordinate;z_coordinate)’ for all the points in geometry]
’.’ is the coordinate decimal separator, and ‘enter’ is the separator between different commands, so each command is on a different line in a script.
A script contains multiples commands and the last command has to be ’end_auto_script‘.
You can generate a list of commands as bellow in Excel with macros, Dynamo or with another familiar program or tool.
This script will generate the elements in the model like in the picture bellow:
In order to create elements using commands as the ones above, when running one of them or the script the following snap modes have to be disabled: extension, tracking, ortho, relative and length on element.
All the commands executed by the user are recorded in the history of the console which is accessible in the input console line (E.G.: selecting an element, calling a ribbon or menu command like creating an element, etc. …).
For checking any executed command syntax, scrolling through the commands history is possible by clicking the input console and pressing left arrow key for each command (using right arrow will walk you back to the last executed command, opposite to the left arrow key, but only after starting to use left arrow). To copy it the recommended way is by selecting the text with the mouse, right clicking it and selecting copy from the contextual menu.
2.2. Script saving, recording and playing
If the script is generated with Excel/Dynamo/etc. then make sure the generated file has the extension set as .ads.
For manual script creation a text file with ads extension is needed. It can be created with Notepad or any other text file editor. After the creation of file copy the script described above at point 2.A. in the empty file and save it as your_script_file_name.ads .
For script recording in AD, right clicking in the input line of the console and choosing ‘start recording’ from the contextual menu starts the recording. After the user interaction with the program (E.G.: selecting an element, calling a ribbon or menu command like creating an element, modifying options in a dialog, etc…), right clicking in the input line of the console and choosing ‘stop recording’ a dialog is launched for choosing the name and the location of the script. There are some limitations that are listed at the end of the document.
To play the script for scenario 2.1, right click in the input line of the console and choosing ‘Load script’ from the contextual menu starts a dialog to choose the script file. After choosing it AD start playing the commands from the script one by one with a delay between them. The user should not move the mouse or press any key while playback is in progress. At the end a message will be printed in the console that notifies the end of the operation.
3. Model calculation and reports generation
At this step start recording a new script as described above. The automatic wind, snow, traffic loads, etc… and combination must be generated if needed. Then the analysis model should be created, maybe also the concrete analysis, steel analysis, etc…. Then in the report generation dialog add the needed reports and optionally change the report type: (Doc, docx, xls, xlsx(for the these first 4 extensions Office suite is required), rtf, txt). In the gif sample, the selected type is xls but in the script rtf type is selected in case Office is not installed. The report is generated in the document folder of the model and it is not automatically opened.
In the end you need to stop the recording. The resulting script can be used as a template script and should be modified/adapted to include the creating elements commands (from the point 2.1.). They should be added right after the last set_unit command:
4. Running the script in batch mode.
At this step you should use a copy of the backup model from the 1st point. Running a batch mode can be achieved by running a bat in which the command is having the following syntax:
“X:\Path to AD\Bin\AdvanceDesign.exe” /s “Y:\path to script\script name.ads” /m “Z:\path to model\model name.fto”
“C:\Program Files\Graitec\Advance Design\2021\Bin\AdvanceDesign.exe” /s “d:\AutoTests\models for new tests\newtest\combined script.ads” /m “d:\AutoTests\models for new tests\newtest\FTDoc15.fto”
A bat file can be created in Notepad and saved as ‘file_name.bat’ when selecting all types as the extension in the save as dialog.
5. Scripting recording and playback limitations
Double-click in pilot; instead, used right click or other commands
Combos in toolbars.
The Data Grid dialog (different technology, in work).
Buttons that open dialogs in Property list and the recording of the GUI operations in that dialogs.
Changing properties in property list commands might have to be updated at each version/subversion of AD because the commands are depending on the identifiers of the properties which are changed almost each version.
Changing the sections and materials for elements from property list.
Changing height for level in Property list
Double-click on result curves in order to save them as *.jpg
Only basic modifications in tables are supported
The measurement units must be the same as the ones installed by the kit
When creating a circle, the radius will be specified in console, not by clicking on the screen.
Modifications of snapping are to be done using the toolbar/ribbon.
Creating loads on selection.
All needed section cuts will be created before starting to register the script.
Mesh preview for planar elements.
Selecting the work plane.
When creating the analysis model, the script should compute a new analysis. When automatically running, if an analysis was computed for the current model, the check boxes for analysis types are disabled, therefore the test will try to open an existent analysis (which does not exist since we should run on a clean model). Therefore, when registering the script, even if the model is a new one and the option to create a new analysis is already selected, select “Create new analysis” and then the analysis type(s).
Do not use right click in reports window. Use instead left click and the existing buttons.
In order to change the cases/combinations for the report, do not use the Cases/Combinations window. Instead, use the Report properties window (select report and click Properties button) select advanced options to expand the dialog and check the specific case/combination and use the analysis type combo from the below of the extended window:
When adding more family cases or loads, do not use the keyboard to insert the number. Use instead the arrow buttons.
The two slides for size from the display options window (Alt+x): or from the ribbon
The window for pressure generation.
6. The power of automation
This tool is very efficient for our QA system but can be very useful also for anyone who wants to automatize repetitive scenarios but also to feed Advance Design with entire building structures extracted from another application. Just do the scenario inside the application, save the script, adapt it if you need it and run it.
One of the specific and more difficult types of reinforcement to model in Revit is punching shear reinforcement on RC slabs. In this short article, we will look at how you can improve the process of preparing the drawing documentation in Revit by generating punching reinforcement using the Dynamo script, based on the reinforcement calculated in Advance Design.
Apart from the preparation of the script in Dynamo, the operating procedure consists of several simple steps:
Calculate the Punching Shear Reinforcement with Advance Design in a model synchronized with Revit.
Export the Punching Shear Reinforcement results from Advance Design to Excel, using results tables.
Create and Run a Dynamo script that reads the data from the Excel sheet and generates the appropriate reinforcement in Revit.
The basis of the presentation will be a RC slab supporting columns that is calculated in Advance Design and then synchronized with Revit. Although we use a simple model with some plates and columns to present the process, we can successfully apply it to real projects.
In the example, the design calculations of reinforcement in reinforced concrete slabs were carried out, as well as the verification of the shear punching along with the determination of the required reinforcement.
In the case of bending reinforcement in the slab, we can automatically generate the reinforcement in Revit using Advance PowerPack tools. Also, with the use of the PowerPack, we can create additional structural reinforcement, such as edge or hole reinforcement.
In this example, however, we will only focus on the punching shear reinforcement. For this purpose, we export the report table ‘Provided punching reinforcement around perimeters’ from Advance Design to Excel sheet. The table contains all the data we need, including the ID numbers of slabs and columns, the location of perimeters with punching shear reinforcement, the number and diameter of bars in the perimeters as well as spacings.
The Dynamo script needs only one input – Excel file. It extracts data from the spreadsheet and then groups the read data relative to plates and columns. Then the existing floors and structural columns in Revit model are found using the numbers stored in the ‘mark’ parameter, which was completed during model synchronization with Advance Design. Then other required information is collected from the Revit model, such as floor thickness, reinforcement cover or column geometry parameters. In the next step vertical bars of the shear punching reinforcement are generated, and thanks to the fact that they are grouped into perimeters, bars can be inserted as one set in Revit.
In addition to importing geometric information, the script can complement a number of other data. For example, for created rebars the „mark” parameter could be modified by combination of ID numbers of a floor + column + perimeter. Depending on the needs, we can group the bars in various ways, as well as add some shared parameters with the identification data, in order to be able to use them in reinforcement tables, tags or filters.
This is an example showing how Dynamo can be used to generate rebar in Revit saving a lot of time on the modeling and detailing side, but it shows as well the great potential that lies in the ability to automate the process of creating drawing documentation, especially with the use of detailed results from Advance Design!
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Advance Design 2021.1 Update is enhanced with new functionalities and improvements with high benefits for the end-user. It is articulated around a few main subjects:
Modelling and workflow enhancements
New options and improvements to the Steel design
New options and improvements to the Concrete design
Improvements to concrete and steel Design modules (previously known as BIM Designers modules)
Among many new functionalities and improvements, we would like to highlight:
Exchange of load combination definitions with Excel allows easy management of load combination definitions by using new Export and Import
Improvements to the transfer of loads to Design modules allows easy transfer of the list of definitions of load combinations to design modules.
Increased performance of Design modules significant increase in work comfort, especially thanks to the substantial reducing the time of generation of drawings.
RC calculations for concrete beams defined as super elements allow the design of multiple span beams having different height and support widths as a single element.
Interactive drawings for steel connections easy and full control over the content of the drawing thanks to the ability to freely compose drawings, easy modification of the location of drawing components, and scale for views.
Update 1 to Advance Design 2021 also comes with many other improvements and adjustments following the feedback received from thousands of users worldwide. It brings also a big number of corrections of known problems and also includes all the fixes and improvements made with the previously released Hotfix 1 (2021.0.1) and Hotfix 2 (2021.0.2).
We are inviting you to take a quick look at the selected improvements brought to the Advance Design 2021.1 Update.
Modelling and workflow enhancements
Advance Design 2021.1 comes with several new features and improvements dedicated to the modelling and workflow.
Exchange of load combination definitions with Excel
Thanks to new Export to Excel and Import from Excel commands we can easily manage load combination definitions by using Microsoft Excel spreadsheets.
Pushover: Displaying a report with status only for selected plastic hinges
When analyzing the results of the pushover analysis by using report tables with the status of plastic hinges, the content of these tables is now filtered to the current selection of elements in the model. It greatly facilitates viewing the results, as we can focus on the statuses of plastic hinges from selected elements only.
Simultaneous creation of holes for many surface elements
When creating holes in surface elements, it is now possible to create a hole in multiple elements simultaneously on the basis of a polyline cutting through several contours.
Shortcut to the Section Editor directly on the ribbon
To facilitate and speed up the opening of the module for creating and editing cross-sections, an icon with the command to open the module directly has been added to the Manager ribbon.
Thickness in tooltips
The Thickness property has been added to the list of available attributes to be selected for the content of tooltips.
System names on the color legend
When displaying a color legend for elements colored by systems, in addition to system ID the name of systems is now displayed. It greatly facilitates the identification and improves the quality of the created documentation.
Improvements to the transfer of loads to Design modules
To improve the transfer of load-related information when transferring data from the Advance Design model to the design modules, new options have been added to easily transfer the list of self-created or modified definitions of load combinations to design modules.
New possibilities for Steel Design
Advance Design 2021.1 comes with several new powerful features dedicated to the design of steel structures.
The new version of the Canadian code for the steel design – CSA S16-19
Since version AD 2021.1 it is possible to perform design calculations of steel linear elements using the current version of the Canadian CSA standard: CSA S16-19.
Update of the Canadian CISC 11 steel section database
Steel profiles from the CISC 11 catalogue (the 11th CISC handbook) have been updated. The changes mainly concerned with changes in naming, adding missing profiles to catalogues and slight changes in the values of the characteristics for a few selected profiles.
Improvements to displaying results of the steel design
A number of improving changes have been made to the presentation of design results of steel elements (according to Eurocode 3) in the Shape Sheet window and related reports. These changes increase the readability of the results as well as allow for a more detailed verification of the results. The most important of these are:
Uniform rules for the presentation of results for individual strength checks.
The cross-section class is now displayed for each check separately, determined on the point where the check was done.
Replacing the oblique bending check by bending with an axial force, bending with shear forces, and biaxial bending checks.
Imperfections on steel columns defined as superelement
Steel columns defined as superelements can be used for the automatic generation of imperfections (according to Eurocode 3). During the generation of forces, the user can decide whether to consider the elements that intersect the superelement.
Improvement in the creation of generic steel joints
To facilitate and speed up the definition of generic joints for steel elements, the command to create them based on the current selection of steel elements has been added. A new command is available on the right-click menu and creates a single connection for steel elements that are in contact at the same point.
New possibilities for Concrete Design
Advance Design 2021.1 also comes with several improvements dedicated to the design of Reinforced Concrete structures.
The new version of the Canadian code for the concrete design – CSA 23.3-19.
With the Advance Design 2021.1 Update it is possible to perform dimensioning calculations of concrete linear and planar elements using the current version of the Canadian CSA standard: CSA 23.3-19.
Superelement for RC beams
The super element concept is now applied to the concrete linear elements for the reinforcement design according to Eurocode. This gives a possibility for the design of multiple span beams having different height and support widths as a single element
Extension of the list of rebar diameters for Poland
In order to enable the calculation of the real reinforcement with the use of reinforcement diameters used on the Polish market, new diameters (18, 22, 28, and 35) have been added to the list of reinforcement bar diameters available on the reinforcement settings window. This change is available for projects having the localization set to Poland.
Improvements to Design modules
In the latest version of the Advance Design, many improvements have been introduced to the Design modules.
Unification of brand names
In the current 2021.1 version, further changes have been made to unify Graitec software brand names. Accordingly, the design modules previously named Advance BIM Designers are now called as design modules of Advance Design.
One of the most important changes introduced with this update of design modules is the increase in performance. Thanks to optimization in many areas, there are significantly reduced times of starting modules, loading projects, calculations and, above all, generation of drawings.
Improvements to the info panel
The info panel content for the RC modules has been supplemented with additional types of results, including: minimal reinforcement areas for beams, more details for top longitudinal reinforcement on beams, buckling information for columns and punching verification for foundations.
The Slovakia localization is now available for design modules, which allows for running the design calculations according to Slovak appendixes to Eurocode.
The new layout of the Reinforcement Assumption dialog windows
The layout of the Reinforcement Assumption dialog windows has been updated for the RC Column, RC Wall and Footing modules. As with most other windows with a new layout (tree menu on the left, parameter fields in the central part, and explanatory drawings on the right), the definition and change of parameters are much easier and faster.
Improvements to views
A number of improvements have been made to the graphical presentation of the RC views, including a possibility for hiding a formwork from 3D views, a possibility for changing a render mode, a possibility for filtering of the displayed loads and a new mechanism for displaying loads on RC beams.
Interactive drawings for steel connections
Drawings generated by the Steel Connection module are now managed by the interactive drawing mechanism, similar to other RC modules. Thank to this the user has control over the composition and all drawing elements.
Double Angle section for diagonals for Gusset Joints
The 2021.1 update of Advance Design Steel Connection offers a new configuration for the Gusset Joint – the double angle section for one, two or three diagonals
Learn more about Advance Design Update 2021.1 from our dedicated webinar!
If you are Advance Design User – Gain priceless knowledge about ADVANCE Design and be the first to know about the new features during Advance Design User Summit 2020!
Dear Advance Design users,we would like to thank you for being a Graitec customer and creating great, innovative and complex projects using our software. Maintaining a positive relationship with you is crucial for us, as is developing the new functionalities of our software according to your needs and indications. In order to thank you for your loyalty, we would like to invite you to our Advance Design User Summit 2020 – an event where you will have the opportunity to gain advanced technical knowledge provided by our professionals, as well as to learn about the upcoming novelties in Advance Design software. We invite you to read the agenda and register your place!
Modeling and defining the values of all climatic loads is a time-consuming process and a source of possible errors. The amount of time spent for the calculation of climatic effects can be significantly reduced, while assuring more accurate results. You can obtain in no time the climatic loads intensity and distribution on your structure using a fast and easy-to-use Advance Design function: the 3D Climatic loads generator.
Implemented Eurocode 1 and National specific standards
Advance Design provides several climatic standards such as NV 2009 (France), NP082-04 / CR1-1-3-2005 (Romania), Eurocode 1, Canadian (NBC2010 or 2015) and US (ASCE 7-10) codes, with different national appendixes:
The choice is done in the global project’s settings.
The structure and roof shape is taken into account, therefore you can create loads on portal frames, parapet walls, lattice structures, scaffolding elements, buildings with dominant face, panels, horizontal roofs, two slopes roofs, isolated roofs, protruding roofs, roofs with awning, etc.
Examples of automatic generation of climatic loads on various structures
Wind loads on multiple roofs
Snow loads on multiple roofs
Wind loads on awning
Snow accumulation on portal frames with a negative slope
Snow accumulation on portal frames with a negative slope
You can automatically generate all the climatic loads on a structure in an efficient way, which saves a great amount of time:
Select the appropriate climatic standard.
Generate windwalls on 3D structures.
Create load case families for snow or / and wind and configure the advanced properties (if necessary).
Access the snow and wind loads values map to define the structure location. With a single click, the values of the wind speed, wind pressure, snow load and exceptional snow loads on the structure faces and roof are automatically defined according to the selected region:
Launch the climatic generator
The climatic load cases and loads are automatically displayed in the graphic area and also, in the Pilot, in the corresponding loads family, providing access to an efficient management:
Accurate and prompt update
If the structure or the loads properties are modified after generating the climatic loads, a single click is enough to update the loads, according to the new conditions.
If you’re a structural engineer looking for powerful steel connection design software, then make sure you tune into our free Advance Design Connection week.
Boost your knowledge and skills with Advance Design Connection free webinars! Advance Design Connection Week is a series of webinars dedicated to BIM Workflow based on Graitec products!
About Advance Design Connection
Advance Design Connection is a powerful analysis solution for 3D Steel connection, fully integrated with Advance Design which is a global structural analysis software including a powerful 3D climatic generator, advanced stability checks and steel members design and optimization. Advance Design Connection can design all types of 3D connections using internal forces on members coming from Advance Design. It provides precise checks, results of strength, stiffness and buckling analysis of a steel joint. Joints are checked according to Eurocodes and North American codes (EC & AISC). Templates for most-used connections are available as well as wide range of predefined hot rolled and sheet welded members.
Join Advance Design Connection Week – free webinars which will be held in English and French.
During the webinars we will cover the following areas:
The workflow from Advance Design to Advance Design Connection –
In this webinar we will demonstrate how to export several connections of a steel structure which is modelled and analyzed in Graitec Advance Design (AD), to Graitec Advance Design Connection (ADC) software. You will see the automatic mapping procedure of sections and as well imported internal forces from AD. In the next step, we will create the connection geometry in ADC and run the analysis and code check process. Finally, we will go through the results of the analysis and status of the connection in ADC.
The workflow from Melody to Advance Design Connection –
We will show the export of a real building attachment calculated with Advance Design to Advance Design Connection (ADC). Then the export of tubular structures from Melody portal to Advance Design Connection. In Advance Design Connection where we will automatically retrieve the profiles and the efforts of Advance Design or Melody, we will build the fasteners in a few minutes and exploit the results.
The workflow Advance Design +Advance Steel to Advance Design Connection –
This webinar will cover the full workflow of steel connection design using Graitec Advance Design (AD), Autodesk Advance Steel (AS) and Graitec Advance Design Connection (ADC). First, we will export the structural node from AD to AS to transfer the sections, the geometry of the connection will be modelled in AS and exported to ADC. Then we will demonstrate how to import internal forces directly from AD into ADC.
The new version of Graitec Advance Design connection (ADC 20.1) –
The new version of Graitec Advance Design connection (ADC 20.1) will be released soon. In this presentation we will focus on new features and functionalities of the new version. Some of the highlights are: Cost estimation / Pre-design tool / Check of missing welds