Revit Tutorial – Displaying Span to Depth Ratio of Steel Beams

In this tutorial we shall look at a method of calculating and displaying the Span to Depth ratio for steel primary and secondary beams. In early scheme design of a steel structure many engineers like to use the span to depth ratio to size members assuming a uniform loading across the beam.

Revit Span to Depth Ratio on Steel Beams

Revit can be used to calculate and display the Span to Depth Ratio by creating a shared parameter and making a simple formula. Typically, a span to depth ratio of 13-15 is used for primary beams and 18-20 for secondary beams. In the following tutorial I will edit a UB family, add a shared parameter and then use the value of this and the structural usage to activate certain colours with filters. The image below shows the filters colouring, green is OK, red is over the limit and yellow is under the limit. To follow this tutorial, you will need Revit 2016 or later.

The first step is to create a shared parameter, this needs to be shared as this may need to appear in a schedule or be taggable. On the Manage Ribbon click the Shared Parameters command as shown below.Shared Parameter Command

If you already have a Shared Parameter file, then click the New Parameter command as shown below. If everything is inactive, then you will need to create a new parameter file by clicking the Create button.Shared Parameter Dialog Box

You will then be presented with the Parameter Properties Dialog. I am naming the new parameter SDR (Span to Depth Ratio) but you can use something else if you prefer. You will need to ensure that the new parameter is created as a Number. Click OK to both dialog boxes. Your new Shared Parameter is now ready for use.Shared Parameter Properties Dialog Box

Next you edit a Universal Beam family (or other section type for non-UK members). In the Project Browser, open the families folder and browse to Structural Framing. Below I am adding the parameter to UB-Universal Beams, but you can add this to any Section you require.

Families Folder in the Project Browser

Right Click over the family and select edit. You are now in the Family Editor. On the Home Ribbon click the Family Types command as shown below

Revit Family Types Command

In the Family Types Dialog box click the New Parameter command as shown below.

New Parameter Command

In the Parameter Properties Dialog click the Shared Parameter radio button and then select the Select button as shown below.

Create Parameter from Shared Parameter File

Select your new SDR parameter and click OK. You now need to set the new parameter to Instance and group the parameter under Structural Analysis. Click OK. You should now see your new parameter in the Structural Analysis group.

Set SDR parameter to Instance and Structural Analysis

Create the following formula. round(Length/Height)

Parameter Formula

This will take the length of the beam and divide this by the section height. Note that the section height appears under the Structural Section Geometry group. We then round this number to get a ratio value.  Save your new family and repeat for other families where you want to calculate the span to depth ratio.

Next you create a project parameter for your Span to Depth Ratio. This will enable you to create a filter. On the Manage ribbon click the Project Parameter button as shown below.

Project Parameter Command

In the Project Parameter dialog, click the Add command. You will then see the Parameter Properties dialog as shown below. Configure the dialog by selecting Shared Parameter, select your SDR parameter and then click OK. Make sure that Instance is checked, group the parameter under Structural Analysis and check the category, Structural Framing. Click OK.

Revit Parameter Properties Dialog

You now complete the last step to create a series of filters to colour the beams by their span to depth ratio. In this example you create a filter for secondary framing. You need to ensure that you have secondary framing in your project for testing. In a Project with the edited families that you have created in the steps above, open the Visibility/Graphics Override dialog and select the Filters Tab as shown below.

Visibility Graphics Override Dialog

In the Filters tab click the Edit/New Button at the bottom of the dialog box. In the Filters Dialog box select the New command in the bottom left as shown in the image below.

Revit Filters Dialog

In the Filter Name dialog box type Secondary Framing – Span/Depth OK.

Filter Name Dialog

You can now set the Category, Structural Framing and then set the AND rules to the following. ADR is greater that or equal to 18 AND SDR is less than or equal to 20 AND Structural Usage equal Purlin. Note that the Structural Usage may have differing terminology depending on the regional settings and template applied. Click OK.

Filters - Adding And and Or filters

You now select the Add command to add your new filter into the Visibility/Graphic Overrides Dialog.

You can then add green to override the linework and for extra impact add a solid green shade to the members. Anything that displays green is now in the correct span to depth range.

Filters applied to VisibilityGraphic Override Dialog

Once the filter has been set your secondary framing will appear green when the correct span to depth ratio is achieved. Note that you can create additional filters to show members that exceed and are too deep. You can also colour the SDR values in a structural framing schedule.

Hope you find this useful? I will try and create a tutorial video when I have some time.

LawrenceH

Revit 2019 Tutorial – Analytical Model Visualisation

Quite often when structural engineers are viewing the analytical model within Autodesk Revit it can be a little difficult to see which members are fixed or pinned or have specific release conditions set. The standard way to achieve this is to select the analytical bar and then look in the Properties Palette for the information.

The image shown below is a typical representation of the analytical model with the loads and end colours shown.

revit analytical model

Here you can see the same model  with some filters applied to help visualise fixed and pinned conditions.

revit analytical model with filters applied

The filters are set within the Visibility/Graphic Overrides dialog box. In the example below, I have chosen to indicate a Fixed or Pinned condition by using the colours red and green. Note that I have also had to create a separate filter for columns.

visibility graphic overrides dialog box

In the image below, you can see the new OR functionality being used to set a filter that either has the start or end release set to Pinned.

revit 2019 filters using or statement

I would suggest that you create a separate view within your current structural template to enable the engineers to easily check the release conditions on the analytical model, this is much easier that selecting each element and viewing the Properties.

Hope this Helps,

LawrenceH

Autodesk Revit to Autodesk Robot Structural Analysis – Send Options

Happy New Year and look forward to all the good things planned for 2017! A few Autodesk Revit Releases back (Revit Structure 2015), Autodesk made a change to the integration with Autodesk Robot Structural Analysis to allow the transfer of data via an Intermediate .smxx file (Structural Binary file for transfer). Whilst this new format offers some benefits, the older method did have a few additional features that have not been incorporated within the .smxx export.revit-to-robot

The most useful of these were around offsetting structural members and the use of System panels and mullions.

Here is the process of transferring offsets in Revit to offsets in Autodesk Robot Structural Analysis. The beams have a z Offset Value of -50 set in the Properties Palette.

structural-framing-offset

When the model is ready to be transferred to Robot Structural Analysis, hold down the Ctrl Key whilst clicking the Robot Structural Analysis Link command. You can then click the Send Options and select the ‘Use drawing model offsets as analytical’ check box.

revit-to-robot-options

Here is the result in Robot Structural Analysis.

robot-structural-analysis-offsets

Some of these legacy features can be useful so the Ctrl Key can revert back to the legacy method. Please be aware that results cannot be transferred to Revit using the ‘old’ method.

Hope this helps,

LawrenceH

Introducing Autodesk React Structures – New Structural Analysis BIM Software

Autodesk announced earlier this month that they have released a technical preview of a new structural analysis tool named Autodesk React Structures. The software promises to bring exciting new collaboration tools and workflows to structural and civil engineers and further integrate design and analysis results directly into the structural BIM workflow.

Autodesk React Structures - Main Interface
Many of you will be familiar with Autodesk Robot Structural Analysis Professional which is the current Autodesk tool for analysis of Steel and Concrete structures. Whilst this is a very capable design tool the interface and workflows with other Autodesk software has not really developed since Autodesk acquired the technology back in 2006 from Robobat. At present it is very obvious that React Structures is based on the Robot platform but the clunky Robot interface has been completely re designed and re thought to give a very fresh, clean feel to the software which makes it much more intuitive.

Autodesk React Structures - Ribbons

As you can imagine, being a technology preview, the software is still in a very early design stage and many of the functions and commands are yet to be implemented but the ribbon does hint to some nice future functionality.

I will certainly be keeping a close eye on the development of this product so look out for future posts and hopefully, some tutorials. If you would like to test the software preview for yourself then click the link below:

http://react.autodesk.com/get-started-now/

Have Fun,

LawrenceH

Revit Structure 2014 Tutorial – Analytical nodes

Link to YouTube Video: http://youtu.be/J2_iddaJzLg

When transferring models from Revit Structure to structural analysis tools one of the biggest issues is often that the original analytical model within Revit Structure has inconsistencies, these being isolated nodes, beams not connected etc.

Isolated Nodes

Trying to identify these issues can be time consuming and a little tricky but Revit Structure 2014 has some great new tools that can help with these issues. By Default, each node now has a read only property which enables the user to see the connectivity of the node.

Node Read Only property

 

Autodesk have also included two filters within the standard template which will enable you to very easily identify issues with a Revit model.

Nodes - Filter Applied

 

Take a look at my short tutorial video, I think this is a really useful tool for those that are transferring from Revit to Analysis.

Link to YouTube Video: http://youtu.be/J2_iddaJzLg

LawrenceH

Revit Structure 2013 – New Analytical tools

The last release of Autodesk Revit Structure saw some major improvements to the way that an analytical model can be displayed and edited. Colour coding was introduced to visually see the start and end of the analytical line and a new tab was added to the Visibility/graphics dialog box to facilitate the display of the analytical model.

Revit Structure 2013 now adds the following improvements to the Analytical model and associated tools:

  • Bar and Node display
  • Load Combinations from analysis software
  • Valid Material Check

You can now display nodes within Revit Structure and there is support to allocate nodes and bars a unique number. I’m assuming that this information will be passed from the analytical software directly to Revit Structure but I haven’t checked the updated API for this functionality. The image above shows the bar numbers tagged in a locked 3D view.

Load combinations can now be passed from third party analysis applications directly into Revit Structure. This could be a very handy feature when using multiple analysis tools as the combinations should be able to support a two-way transfer, again this would need to be tested.

In the above image I have used Filters to show release conditions of the bars in the analytical view. One of the main questions I get from engineers is how to effectively view the release conditions initially set in the model by the structural technicians.

Project Storm is now available for Revit Structure 2013 and can be downloaded from the Autodesk Labs site. The analysis display styles are directly supporting the visual style of the results within Revit Structure 2013.

LawrenceH

 

OASYS GSA 8.6 link to Revit Structure 2012

GSA Analysis is a highly intuitive tool from ARUP, enabling users to carry out 3-D linear, P-delta, non-linear static analysis, dynamic analysis and more. GSA 8.6 now links with Revit Structure 2012 enabling engineers to import models from Revit Structure 2012 to GSA 8.6. You can also import a GSA 8.6 model directly into Revit Structure; however, this will have some limitations.

I have set up a simple test which is shown below. GSA took through the Grids, Levels and all structural objects. Below you can see the model in Revit Structue 2012.

Here is the same model transferred to GSA 8.6. Note that the transfer should be made from the Add ins tab in Revit Structure.

For further information and a free trial visit the following link:

http://www.oasys-software.com/gsa-analysis.html

LawrenceH