Revit 2023 – New possibilities for structural engineers

A recent change to the methodology of Revit structural analytical modelling has enabled new workflows and capabilities when representing the Revit design model. However, automation is now more relevant than ever, as the analytical model is not generated automatically while the physical model is being built.

The massive benefit of this new workflow is that engineers can now create early structural design models in Revit without having to worry about the actual physical members. For example, an early design of a building structure may need some columns and framing to support a floor. However, at an early stage the materials and geometry may not be known. As the design progresses, the analytical members can be associated with actual physical elements. This allows Revit to be used much earlier in the design process and, importantly, to reuse and develop the design model right to the completion and handover of the model.

When representing certain structural systems and configurations, the analytical model can easily be defined and edited and then associated with the physical element. A great example of this is when an in-place family has been used. Previous releases of Revit would not allow an analytical representation to be defined, however, you can now define an analytical model for in-place families which is useful for complex foundations.

In future releases we will hopefully see more Revit categories supporting an analytical model, an obvious addition would be the recently added bridge and infrastructure categories. It would also be useful to create panels from façade elements for wind loading.

In the image shown below, the Analyze ribbon is shown with the new member and panel tools to generate a structural analytical model that can be transferred to multiple design and analysis tools without having to invest time in modelling an actual physical structure.  

When defining the analytical members, there are different methods to model beams and columns, namely, top point definition for columns or start/end point definition for beams and braces. Of course, the members can be modelled in a 3D view using ‘enable 3D snapping’ on the options bar. The properties of each element can then be defined and set.

Revit provides two types of analytical elements, a member and a panel. The members can be used for beams, columns, and braces. The panels would be used for wall, floors, foundation slabs and similar elements. Panels can also be curved which allows better interaction with the analysis software. It is a good idea to create a series of view filters to differentiate between the various elements. In the image below you can see simple frame with columns shown in magenta, beams in blue and bracing in yellow. This has been setup with simple view filters that colour each element based on the structural role.

Another new feature is the ability to show the section on each member, very similar to Robot structural analysis. This is simply enabled by switching on cross sections within the visibility/graphic overrides dialog.

Of course, once the analytical model has been built you can transfer it to Robot Structural Analysis Professional directly from Revit or other analysis tools with dedicated interfaces.

The image below shows the model and results transferred back into Revit. Each load case and the various results can be plotted directly on the analytical model and presented in Revit along with other typical views.

So, in conclusion, Revit 2023 allows engineers to work with Revit at an earlier stage, define a flexible analytical model that is controlled by the engineer. The analytical model can be suitably simplified and has the potential to represent many more structural conditions than previous versions.

A great step forward!

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Secant and Contiguous Piled Walls – A Revit Tutorial

Piled wall systems can be challenging to model in Revit, especially when the project stage goes beyond a concept into detailed design. This tutorial will focus on the use of Revit to manually model and add the sequencing data to the piled walls.

Of course, much of this process can be automated with Dynamo which may be a topic for a future tutorial but, for now, lets focus on the process of creating families and piled walls. The below image shows a typical output in a plan with pile construction sequencing and the hidden detail with a capping beam as well as the 3D model.

This tutorial will focus on two primary parts:

• Revit family creation
  • The actual development of the Revit family and types to support the modelling and detailing.
• Creation of the Secant Piled wall model
  • The modelling of the piled wall system and the attribution of relevant data.

Revit Family Creation

Although the UK content library includes a series of pile caps and single piles, these are all based on a steel tube. For this reason, we will create our own pile family and add two types, one for the primary and another for the secondary pile.

Just for a little background, the primary pile is often cast from plain concrete and unreinforced. These are constructed first. The secondary piles are then ‘cut’ into the primary piles in an overlapping pattern with a higher grade of concrete and reinforcement. The primary piles are shown in the above image in white and the secondary piles are shaded in grey.

We will start by creating a new Structural Foundation family from the Metric Structural Foundation.rft template.

On the File Tab, select New – Family. In the New Family Select Template file pick the Metric Structural Foundation Template file.

On the Create tab, select the Extrusion tool, and sketch a circle as shown below. Add a diameter dimension as shown below.

Label the diameter dimension with a parameter, remember that if you want to tag the diameter you will create a shared parameter. In this example we will rely on scheduling and tagging the Type name.

Complete the extrusion and then open a front elevation view. To control the length of the pile, create a reference plane and add a label to the dimension as shown below. This is created as an instance parameter.

We will now create two family types, one for the primary (soft) pile and one for the secondary (hard) pile. Each of these family types will have a different grade of concrete which allows one pile to ‘cut’ another.

To begin, we will first add a material parameter to the extrusion. Select the extrusion and in the Properties Palette, associate the Material to the Structural Material as shown below.

In the Family Types dialog, create two new types as shown below. You can configure your concrete materials to display the primary and secondary piles as required.

When the families are used in Revit, the piles will automatically join to one another and, as they are different materials, the piles will be cut. If the cutting order is wrong you can switch the join order.

Anyway, I may create another tutorial to automate this process using Dynamo for those that are interested.

Hope that helps,

lawrenceh

Naviate Rebar unveiled for Revit 2023

Our new breed of reinforcement modelling tools, Naviate Rebar, has been launched earlier this week during the annual Autodesk University conference. Naviate Rebar is built on a completely new framework which utilises many of the new and improved reinforcement tools that Autodesk have introduced such as rebar constraints and rebar propagation. To download a trial please visit https://www.naviate.com/naviate-for-revit/naviate-rebar

The rebar modelling tools currently include reinforcement generation for Beams, Columns and Walls as well as a series of tools to manage rebar visualisation. I have produced a short YouTube video outlining the main features and functionality of Naviate Rebar.

Some of the new innovations include modeless dialogs where rebar can be applied to the elements and previewed directly within the Revit model negating complex preview functions within the dialog boxes. Each dialog has a clean, simple arrangement of tools to increase productivity and simplify usage. For example, the column reinforcement dialog shown below will handle square, rectangular, and circular columns using the same, simple column reinforcement command.

Naviate Rebar also supports the simultaneous reinforcement of multiple elements, even if the geometry `varies’. In the example below, a series of ground beams have been selected. The lengths vary, but, since Naviate Rebar also creates rebar constraints, the rebar adapts to each beam.

Additionally, the reinforcement settings can be ‘read’ directly from the elements, so if you have a similar reinforcement configuration you can read the settings from one element, make the relevant changes in the dialog, and then directly apply the rebar to other elements.

Reinforcement settings can also be saved with the various elements which is incredibly useful if you want to make changes or edits to several members with the same reinforcement. The interesting point here is that, where possible, the reinforcement is edited rather than recreated. This means that annotations, tags and multi rebar annotations are retained and not deleted from the drawings.

This is our first release for Revit 2023, we are already working on several additions such as structural openings and connections. Of course, the focus with Naviate Rebar is the efficient modelling of reinforcement, regardless of national codes and practices. Our Naviate Accelerate and Naviate Structure tools will enable rebar details and schedules to be produced in accordance with local standards and design codes.

LawrenceH

Revit and Dynamo Tutorial – Placing family instances at world coordinates

During my years of training Revit, many clients ask if there is a tool to place a Revit family at a world coordinate, perhaps issued by a contractor or a surveyor. In AutoCAD, due to everything being modelled from the World Coordinate System or WCS, this is an easy task. You simply type in the easting and northing. However, Revit’s coordinate system for placing families uses the internal origin which will not be the real-world coordinate. We also must consider the possible rotation of the site in relation to the project north.

A simple solution is to use Dynamo to transform the coordinate system and place a selected family at the coordinates. I have wanted to create a tutorial for some time now and I have finally got around to it! The most efficient method for placing the families is to use Dynamo Player, however, if a number of families are required from a list, then we can read a text file, comma separated file or Microsoft Excel.

Above I have included an image of the complete Dynamo Script but will step you through each of the groups. If you want to see a detailed, step by step guide then I have created a YouTube video here:

The first step is to get the project base point built in parameters which get the East/West, North/South and Angle to True North. Although there is a node that retrieves this information directly, the node will not update or refresh so this is a better method.

Next, we create to inputs for the Easting and Northing, these values are subtracted from the Project Base Point and a coordinate system is created.

We can now create another coordinate system at the internal origin of Revit and then rotate this system to take into account the project north rotation. The family instance is then placed at the coordinate system. The Dynamo script should ideally be executed within Dynamo player to allow for multiple coordinates and families to be placed simultaneously.

If several families are to be inserted at world coordinates then you can create a dynamo script that reads a series of coordinates that are stored in Microsoft Excel or a simple comma separated file.

Anyway, feel free to watch the YouTube video where I create and explain the script step by step!

LawrenceH