The proposed tool is a Dynamo script that takes a user-defined Revit building mass and visualizes the effect of material properties on the size of the structure needed to support the gravity loads within that mass volume.
Intended users
- Building owners and architects, or engineers offering solutions to them
Need you’re trying to provide a solution or support for
Inform owners and architects of the influence of material choice on a framed building. The objective of the program is to give owners and architects a quick napkin-calculated visual of how bulky or slender the structural elements will need to be to support the mass volume they want to envelope.
The outputs will show how much room, floor, and wall space is taken up by the structural elements, and what the resulting cost will be. These, combined with the graphical rendering in Revit, will give the stakeholders a basic idea of how the structural material will influence the look of their building.
Inputs
- A Revit mass element (in the proof-of-concept), a rectangular prism will be used
- Number of floors and bays
- Design gravity load per square foot (uniformly distributed across every floor)
- [option] Material: specify material (steel, concrete, or user-defined tensile and compressive strengths (ft and fc, [ksi])
- If steel, assume 29000 ksi strength and fixed-proportion W-shape steel beam section (no table lookup, just linear scaling)
- For other materials, assume rectangular section
- [option] Frame type: moment or X-braced (non-concrete only)
- Cost of material per CF
Underlying logic of the model you’ll implement
- Draw the structural grid with boundary elements centered on the boundaries of the Revit mass (the elements will occupy some of the target mass).
- Determine the gravity forces (axial F, shear V) and moments (M) acting on the system
- Assumptions
- Floorplan symmetry to simplify calculations for the proof-of-concept
- Negligible self-weight
- Linear structural analysis
- Simply supported base (moment release)
- Design elements based on maximum loads (F, V, M) at each story
- For moment frames, design beams and columns based on max F, V, M
- For braced frames, design beams based on F, V, M, and braces and columns based on F
Outputs
- % target mass remaining (after structural elements)
- Volume
- Floor area
- Wall area
- Structural element cost per SF of floor area