ADVANTAGE STEEL SUMMER 2019 | 35 Lastly, not all building code jurisdictions are as open to off-site construction. It is best to consult with the Authority Having Jurisdiction (AHJ) early in the process to understand the requirements and necessary approval timeframes. Contract Document and Structural Analysis By using structural steel as the underlying structure for PPVC buildings, designers can take advantage of well- established workflows while finding new opportunities specific to PPVC buildings. For example, to define individual modular chassis, the authors have developed scripts in Dynamo, a visual programming plugin for Autodesk’s Revit, to define all parameters, including dimensions, member sizes, and framing configuration. Crucially, this model also contains an underlying analytical model that captures the structural steel member sizes, work points, and end releases as shown in Figure 3. This is done for each type of module within the building, including habitable units, stairs, and elevators. The individual Revit files are then assembled into a master coordination model using an architectural model to guide the placement of modules. An example of an assembled Revit model for a modular building is shown in Figure 4. The BIM is then linked to conventional structural steel analytical programs to facilitate the analysis and design of the structure. In the above example, the analytical representation of each individual module is maintained in the assembled model, and appropriate horizontal and vertical linkages between all modules are automated. Engineers then assign loads and load combinations to the analytical model and go about completing the design like one that would be site-built. However, the vast number of structural elements in a typical modular building makes data management a challenge. In response, the authorshavealsodevelopednovelscriptsusing Grasshopper, a visual programming plugin for Rhinoceros 3D, to sort through all the data, present it in meaningful ways, and identify critical values for design purposes. FIGURE 3: Model and analytical view of chassis framing for individual module. FIGURE 4: Assembled chassis modules into master model. www.jitech.ca CELEBRATING THANK YOU FOR YOUR SUPPORT! Downtown MONTREAL 1111 St. Urbain Suite 117 Place d’Armes Place des Arts First Street Downtown MIAMI 223 E Flagler Suite 320 2004 2019 15 YEARS FEATURE