algorithmic modeling for Rhino

Cross Section Optimization not working

Hi all,

I am trying to optimize a structure's cross section with the "Optimize Cross Section" component. To start off with, I've been trying with a simple supported beam.

Here is what I want:

I want Grasshopper to pick the smallest possible cross section for each single segment of the beam (13 in this case) and stay under a given maximum displacement.

Here is how I proceed:

I want to use a rectangular (trapezoidal) cross-section. Therefore, I created a list with certain heights, which is the base for a list of trapezoidal cross sections with different heights and a single width. For the first analysis, I am using the "Cross Section Selector" component with the smallest cross section and for the "Optimize Cross Section" component I am using the list I created.

Here is my problem:

When I try doing this with the preset standard steel cross sections (blue group), it works fine. It picks different cross sections for each segment and the displacement stays under the input number (see image below). However, if I use a rectangular/trapezoidal cross-section from my own list (red group), it picks the first cross section in the list for all of the segments regardless of whether it exceeds the given maximum displacement or not. If I try to reverse the list, it again picks the first in the list, which is the biggest one in that case.

I assume I have done something wrong with the list.