2 Units
Step 1 - Generative Design Framework
Step 2 - Generative Design Study
To represent the ceiling sandwich depth controlled by the beams , I modeled two rectangles lofted together. The second rectangle was translated down using the depth calculated from the beam demands.
After setting up the geometry, I used it to calculate the compressive load on the column and moment demand on the beam using the bay sizes. I also calculated the number of columns to be used later on.
After calculating loads, I designed the beam and column and calculated the evaluators. First I calculated the concrete beam depth required, keeping the width at a constant of 20 inches (this can be adjusted to suit design needs). I also designed the area of the column needed to take the compressive loads ( I ignored rebar for simplicity). I then calculated the free volume inside the room where I subtracted the original square footage times height by area taken up by the columns and ceiling sandwich. This value will be maximized in my design for maximum open space per an architect’s desire.
The second evaluator was the volume of concrete from the beams and the columns which are proportional to cost and embodied carbon and therefore, should be minimized.
Finally, the outputs were set as the free volume, volume of concrete, radius of column and depth of ceiling sandwich. For the generative design the free volume and volume of concrete were optimized.
Step 3 - Generative Design Study Results
For my generative study, I chose to optimize maximizing the free volume and minimizing the volume of concrete. I ran 20 combinations.
The generative design results are shown below. When looking to maximize volume of free space and minimize volume of concrete, tradeoffs need to be made.
One combination that keeps the volume low while still having relatively higher free volume is the design shown below.
Looking at a scatterplot with the volume of concrete on the x axis and free volume on the y axis can assist in making a decision that provides the best tradeoff. As the volume of concrete increases, the free volume seems to increase. The trend shows a steeper increase at lower concrete amounts and a plateau in free volume as the concrete amount increases. This relationship is due to the smaller bay sizes leading to shallower ceilings and lower column sizes resulting in more space. Although the amount of beams and columns increase with more bays resulting in a higher volume of concrete. One optimal design is shown below where the free volume is nearly maximized while maintaining a low amount of concrete. This design relies on large bay sizes and ceiling height. The next best option with 9 columns is shown in the image above when looking to pick a design using the other type of plot produced by generative design.
