Tube optimization with Geomgym and GSA

Hi,

I am currently working with the great Geometry Gym plugin for my tube bridge project. I made a model of the bridge with several variables that can be adjusted in Grasshopper. What I am trying to do is to make a structural analysis of the model with Geomgym in GSA and use that gathered data to optimize the variables.

I already created the beams (with their profiles and material) and I started with creating the nodes. However, I constantly get an error when I try to open the model in GSA. GSA doesn't recognize all of the nodes I created in Grasshopper and connected to the 'create node' box from Geometry Gym.

What I need to do is find all of the intersection points of the horizontal beams, the vertical ring sections, the diagonals and the supporting beams. These supporting beams carry the weight of the actual (concrete) floor of the footbridge and the load from the floor of the footbridge needs to be loaded to the intersection of the 'supporting beams' with the 'vertical rings' (as point loads), so not with the diagonals. And I also need all points on the first and last ring section to make that nodes restraint as pins.

The division of the polygons in the vertical ring sections is recognized in GSA, but I can't figure out what is going wrong in the model. Below I added the file as I made it with the creation of the nodes included. I also added a file where the creating of the nodes isn't added.

The first added picture shows the error in GSA and the nodes GSA can't find have a red circle around it. It also says that GSA recognizes '7 structures'...

The second picture shows that the loading of forces is correctly recognized and also the pins in the first and last ring section are applied correctly. But GSA doesn't recognize the intersection points of the diagonals with the ring sections and the supporting beams...

All of the intersections between the beams need to be hinged connections, without restraints. The hinges where the forces are loaded into (z-direction) are the intersection points of the 'supporting beams' and the 'vertical ring sections'.

All of the hinges in the first and the last ring section are pinned (x,y,z restraint - xx,yy,zz not restraint).

Could anyone please help?

Thank you in advance!

Attachments:

Replies to This Discussion

Permalink Reply by Jon Mirtschin on May 22, 2015 at 10:45pm

Hi Stefan,

Thanks for posting, let me know if this helps or not. With GSA, you need to either ensure that the elements are all split into sub elements at intersections, else you need to manually run the model correction tool (not helpful in optimization).

I've attached one image showing an element running all the way to node 1 to 2. BullAnt has a component to split a curve by others curves that intersect it. I only applied it with one set of transverse elements (you can add the rest) but you'll now see that 4 elements are created instead of one.

So if you expand on this you should be able get a single structure, not have disconnected nodes. Note that some other software will seek the intersections for you at time of analysis (but won't then add element intermediate releases).

I hope this helps,

Jon

Attachments: