Saturday, May 6, 2017

Use Case: Modelling Rebar in Revit with Dynamo

From the Autodesk BIM and Beam blog:

Rebar Modelling in Revit with Dynamo Use Case by ABT

Tomasz Fudala
October 28, 2015

In this post I want to tell you more about how one of our customers, ABT bv, used Revit and Dynamo to automate the reinforced concrete detailing of wind turbine foundations.

ABT is a multi-disciplinary consultancy firm, focused on the structural engineering, civil engineering, architectural engineering, building physics and installation engineering knowledge domains, with offices in Netherlands, Belgium and Germany.

In 2014 they moved to BIM-based 3D rebar in Autodesk Revit for concrete reinforced design and fabrication for their wind turbine foundation projects, because they do a lot of these projects worldwide. Around the same time they first started to use Autodesk Dynamo. They are challenged to make these wind turbine projects as “flexible” as possible. Revit and Dynamo are perfect for achieving this as these projects are relatively small, the main focus can be set on reinforcement and they are highly parametric.

When they started to consider a new workflow for these projects they have set a goal to create fully parametric models that includes all the information required by structural analysis, production drawings, bending schedules, … Dynamo takes up a main role in this workflow. By using specially prepared Dynamo scripts, the user can control the wind turbine foundation geometry and reinforcement as well as the Revit sheets, views and even worksets.

For the design of the reinforced concrete foundation they used this specific workflow, which is also displayed in a video at the bottom of this post.

Step 1 – Setting parameters
The initial design is created by setting values and dimensions from within an Excel file. This configuration file consists of a large set of parameters so they handle any situation of this wind turbine foundation.

Step 2 – Reading values into Dynamo
The Dynamo script reads information from the Excel file and creates the initial wind turbine foundation geometry in Revit. This file controls several value of the foundation like overall dimensions, pile length, pile inclination angle, pile count and type, anchor system parameters, mortar system parameters and visual appearance of the Revit sheets.

Step 3 – Drive Revit geometry and add parametric reinforcement
After the shape of the foundations is created they start to create reinforcement. They found out that the best results can be achieved if all the reinforcement is divided in logical groups. The creation of net, circular, radial, and hairpin reinforcement is performed with the help of separate Dynamo files. For that purpose the Dynamo for Rebar package, developed by Thornton Tomassetti, is used. This method gives them extra control on the reinforcement creation and helped them save hardware resources.

Changes made to the design are done in the Excel file, which makes it easy to change all relevant information (i.e. after a comprehensive structural analysis).

Another feature that is included in their Dynamo scripts is the part that manages the collaboration worksets in the Revit project. After the reinforcement is created in Revit, every single position is assigned to a separate, specially created workset. That gave them better control and allowed them to filter and make precise DXF-export for further handling in 3th party tools.

Step 4 – Generate detailed output drawings
Then finally Revit and the Sofistik Reinforcement Detailing tools are used for documenting the foundations.

Demo movie
ABT also posted a nice video to illustrate this workflow on their YouTube channel, which you can watch below.

Special thanks to Sandra Hombergen from ABT and Dieter Vermeulen from Autodesk, who shared us this really nice workflow and story.

There's more information available on the Autodesk BIM and Beam blog.

No comments: