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

Tutorial – The Excitech Toolkit and Reinforcement

I have just created a quick video to showcase some of our Excitech Toolkit tools that could make you more productive when creating and detailing reinforcement in Autodesk Revit. These tools are free to all of our customers

For more information take a look at the following link.

https://www.excitech.co.uk/Insights/Blog/February-2019/The-Excitech-Toolkit

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 2018.1 Precast Concrete Solutions

In the early stages of a design the decision to use precast or In Situ concrete on structural components may not have been fully considered. There are many factors that could influence the design and ultimately the construction processes that are implemented. Some typical benefits of precast is Quality control and speed of construction since we are not working with ‘wet’ materials and not having to wait for the concrete elements to fully cure before other structures can be assembled. However, designing with precast elements is a little like a Lego set, you can only create certain forms with economy!

Revit 2018.1 Precast

Autodesk Revit 2018.1 now incorporates a precast module that was acquired from IDAT a few years back. This solution allows for the conversion of planar walls and floors to precast elements which is perfectly suited to the design workflow as outlined in the above paragraph. We can take the initial design and then at a later stage decide to convert these into precast elements.

Shown below are the new precast tools found on the Revit 2018.1 Ribbon.

Revit 2018.1 Precast Ribbon

As you can see from the image above the tools are focused around the division of singular elements such as walls and floor slabs. The splitting of the walls and floors are governed by Configuration settings. For example, you can set a maximum weight and maximum set of dimensions for lifting and transportation. These tools automate the creation of Revit Assemblies which enable the detailing of each individual precast element and the output of CNC code for UniCAM (Unitechnik) and PXML (ProgressXML). There are many settings that the user can tweak and change and below you can see the configuration for the walls maximum dimensions, weight and jointing.

Cast Wall Settings

Another task that the precast module automates is the placement of anchors, bushings and connectors. These are standard Revit families that can be replaced with specific manufactured parts for full coordination and costing.

Precast Anchors and Loop Connectors - Revit Precast

The reinforcement bar is also added via intelligent macros that allow the end user to configure typical arrangements of reinforcement bar. There is not currently an automated way of placing reinforcement bar around openings such as doors and windows but this bar can be added to the part with the standard reinforcement tools. In the below image you can see that the Area and Edge reinforcement can be customised and also have a library of types configured.

Revit Precast Reinforcement configuration

One of the most powerful features of this software is the ability to generate automatic drawings to detail the precast elements as well as the cast in connections and other placed objects such as electrical voids and similar.

Precast Wall Details - Drawings Sheet

The above image shows a typical drawing that is fully automated. Note that the centre of Gravity is also located to allow for the planning of lifting. The panels also support the tilt method of construction which is also useful.

Check out the 10min Tutorial video below.

LawrenceH

Revit Structure Tutorial – Site Setting Out

In this tutorial we will explore the techniques and tools used to successfully coordinate a Revit project to a survey or OS grid. This process is often neglected which will cost you dearly later on! The problem is that this is only done once at the start of a project so is easily forgotten. A primary consideration is preparing a CAD file so that it is suitable for import into Revit. See Step 1! Get this wrong and the whole process will fail.

 Link to YouTube Tutorial : http://youtu.be/xlO7KF0vsS8

Revit Site

In a later tutorial I will outline the process of coordinating with Autodesk Civil 3D and a 3D TOPO but in this tutorial we will concentrate on a 2D survey, this could of course be in a variety of formats such as DWG, DGN or DXF.

1. The first step is to prepare your incoming CAD data for use within Revit. This will involve checking the UNITS of the CAD file (i.e. millimetres or metres), accuracy of the drawing and the layer configuration. If you have a very large survey then I would recommend using the WBLOCK command to select the relevant data and saving as a different name, this will clip a very large file. You will also need to check the extents of the file, if any data is outside your limits then delete (must not be greater than 20 Miles). At this point, freeze or turn off any layers that you do not want to be visible in Revit

AutoCAD - Preparing the survey drawing2. It is advisable to clearly mark a primary agreed setting out point on the CAD file that can be seen in Revit. This should normally be on a grid intersection and agreed and used by all Revit Buildings and disciplines (Construction, Architecture, Structure & MEP). If you know the consultants, architects and contractors who you are working with try and set up a Revit coordination meeting before any major modelling goes ahead to agree a universal setting out point that all Revit Buildings and models will use.

You can also create a secondary SOP for verification purposes. This should include the Easting, Northing and a level as shown below. If the structure is fairly large then you can consider increasing the precision of the coordinates. This is particularly useful for rotational errors that may occur.

Save the CAD file.

SOP1 setting out point - CAD

3. You are now ready to import the CAD file into Revit Structure. Once the CAD file has been selected you will need to configure the various setting within the dialog box. In most cases you will want to preserve the colours. Set the Layers/Levels to Visible and this will import only the CAD data that is on. Make sure that the units are set to the survey units, i.e. if the original CAD drawing is in Metres set the Import to Metres. The positioning should always be set to Auto – Centre to Centre. This will place the centroid of the CAD Building directly into the centre of the Revit Building (Note that this must not exceed 20 miles).

Revit Cad Link4. You will now move the CAD file to the Revit datum (0,0,0) position. The Project Base point will need to be visible; in the visibility graphics dialog box check the Site Category and then check the Project Base Point sub category.

Revit - Project Base Point

Once you have moved the survey your Building will look similar to the image below. Note that the project Base Point is now at the agreed setting out point (Some contractors may want to use the local agreed coordinate system on large sites for piling etc.)

Move the Survey to Project Base Point

You now set the Revit Site coordinates to match the CAD survey. Click the Manage Tab, Project Location, and Specify Coordinates at Point and select the Project Base Point. Enter the Easting’s, Northings and Elevation.

Set Coordinates

Coordinates

5. Save the Revit Building as the ‘Site File’. You will later insert your Revit Buildings into this file and acquire the coordinates.

6. You now prepare the Building file. Create a new Revit project with your active template and then make the Site Plan current view.

Revit Site Plan

Using Visibility/Graphic command (VV) switch on the Project Base Point.

7. If you have a DWG with the grid and architectural features then import this into the current view using the same rules as when importing the site plan. Move the Building to the agreed setting out point (Grid Intersection). Add a Spot Coordinate to the project base point, this should read 0,0

Model on Agreed Grid Intersection

8. Save the project as the Building File (e.g. Building A)

9. Open the Revit Site File and then import the Revit Building File by selecting the Insert Ribbon and then the Link Revit command as shown below.

Link Revit File

The Linked Revit File will now appear in the centre of your site file. Move and rotate the file to the Project Base Point to match the setting out of the grid. If you are new to this procedure then be sure to watch the tutorial video.

10. You will now acquire the coordinates from the Site file and record these into the Building file. Select your linked Revit file and in the Properties Window click the Not Shared button as shown below.

Select Linked Building File

Once the Not Shared button is clicked you will see the Share Coordinates dialog box. Use the first option which will publish the Shared coordinate system of our site file into the Building file.

Share Coordinates - Publish

11. Close the Site File and Open the Building File. You will see a dialog box asking if you want to save changes, click yes.

12. Open your Building file and return to the Site Plan. You should now see the correct coordinate system and if you change the Orientation from Project North to True North you will see the Building rotate to a True North position.

Building File - Coordinates12. Because the Revit Building file is linked, if the Building file is moved within the Site file then this will be ‘pushed back’ to the Building file and all coordinates and levels will be updated.

Tips and Tricks

Don’t forget to change your Levels to Survey. This will ensure that your project levels are always synced to the Site. Any changes to the site will instantly update the Building files.

Levels set to Survey

Don’t forget to watch the Tutorial Video, a lot to take in!

LawrenceH

Creating a Service Opening family for Revit Structure 2012

In a recent blog I outlined a new method of creating a line based void opening for cutting through structural Beams and Columns within Revit Structure 2012. See link Below:

https://revitstructureblog.wordpress.com/2011/08/19/creating-structural-opening-families-for-walls/

After a few requests I have now created a tutorial video on YouTube to show the creation of the family file and useage within a steel project. See Link Below:

Hope this helps,

LawrenceH