Step 1 - Generative Design Framework
First, we will look at the three design decisions that were explored:
- Optimal arrangement of parking lot spaces to maximize efficiency and minimize risk
- Design Variables
- The slant of the parking spaces
- Number of lanes
- Number of stories in the parking lot
- Evaluators
- Number of cars that the lot can hold
- Number of one-way roads (safer)
- Amount of plan area required to build the parking lot
- Most Important Tradeoffs to Consider
- Slant and the number of cars the lot can hold
- While having a slant would allow cars to enter more easily, thus reducing the number of accidents, it would also take up more room and result in fewer possible total parking spaces
- Number of floors vs construction cost
- Optimal arrangement of seats in a classroom to minimize Covid infection
- Design Variables
- Number of students
- Area of the class
- Arrangement of seats (circular, by rows, diagonal, etc)
- Evaluators
- Number of people in each person’s line of contact
- Most Important Tradeoffs to Consider
- Classroom size vs probability of transmission
- Student density vs probability of transmission
- Designing a warehouse to minimize material usage
- Design Variables
- Column spacing
- Beam and column dimensions
- Concrete and steel strength
- Steel reinforcement ratio (how much steel vs how much concrete to use)
- Evaluators
- Amount of steel and concrete in construction
- Amount of open space in the warehouse
- Max deflection in beams and columns
- Max moments and axial forces in beams and columns
- Most Important Tradeoffs to Consider
- Open space and bay spacings vs concrete and steel volume (is there an optimal point where concrete and steel volume are minimized and sufficient space is left for the workers and equipment?)
- Spacing between columns vs moment and axial force demand (what is an acceptable distance between columns such that the force demand is not too large?)
- The ratio of steel reinforcement to concrete volume (how can we choose it so that both are minimized?)
Step 2 - Generative Design Study
For the generative design, I proceeded with the third option: assessing the location of beams and columns in a warehouse and material properties to minimize construction costs while still allowing for a safe and usable building.
First, the inputs were decided to be the following:
This range of variables allowed me to look at the contributions from each source and how they would affect the overall result (sensitivity analysis).
Several other design variables were kept constant for the purposes of simplicity in this assignment. For the purposes of this assignment, all units are in [kN, m].
Next was the brunt of the work, to calculate loads on the transverse and longitudinal beams, and columns. The ACI-318 document was used as reference in the formulation of all equations.
Once loads were determined, member dimensions could then be calculated from them. Similarly, the amount of rebar and concrete volume followed that.
Once the geometry was finalized, Dynamo geometry was created based on the calculated dimensions of beams and columns. Note that for simplicity, beams and columns were modeled as cylinders instead of rectangular prisms with the same diameter as calculated beam/column dimensions. This was done to reduce the time spent and focus on the Generative Design concept as that was the focus of this study.
Lastly, the chosen outputs are created as “Watch” nodes.
Step 3 - Generative Design Study Results
- The screenshot of the Scatterplot or Parallel Coordinates Graph illustrating the tradeoff that you chose to model and study.
- Provide a brief explanation of what’s being shown in the Scatterplot or Parallel Coordinates Graph and how the tradeoff being illustrated would impact the design decision. What would you do with this info?
- An image of your Dynamo Study Graph (showing all your nodes and the connecting logic) -- You can use the File > Export Workspace As Image... command in Dynamo to save a PNG image to upload with your posting.
To examine tradeoffs and optimal design solutions, the following outputs were selected (also see above in the last step of the Dynamo chart):
- Total Concrete Volume
- Total Steel Volume
- Total Material Cost
- Max Moment
- Open Area/Volume Ratio
Using the Generative Design tool graphical option, certain trends were noted:
- As was previously hypothesized, the generative design helped to confirm that as the bay sizes increased, the moment and axial loads induced on columns and beams would also increase
- While the general trend was that as concrete volume was inversely proportional to steel volumes (need more steel as concrete reduces), there was one outlier that appeared which required high steel and moderately high concrete. Such cases should be avoided in design as they would result in high costs.
- Some options are able to minimize the forces in the members while keeping the amount of total concrete usage relatively low
