Multiple directions for SPC in different Loadsteps

Rahul_P1

Hello,

I'm having problems implementing what follows.

I created a rigid spider at the center of a hole. I now need to create 6 different load steps each with a different SPC for the center of the hole. What varies is the direction of the free degree of the center of the hole.
Basically I have a prismatic joint which changes direction for each loadstep.

As I understand, you can't select a local system for SPCs (why not ?? it would be so much simpler) but you need to link-assign the local system to the node which will host the SPC. Having only one node, at the center of the spider, I can only link-assign one system and thus can't workout the model I'm looking for.

Any help would be appreciated, Thank you !

Marco Serafini

Rahul_P1

Marco,

This is not directly possible,

As a workaround you can quickly create three different models for your SPC of three different directions and run them separately.

model 1 will have the centre node assigned to local coordinate system 1
model 2 will have the centre node assigned to local coordinate system 2 etc

Rahul_P1

That would be a solution for the analysis. Unfortunately I then need the same loading-model for a topological optimization. For the optimization I need all loadsteps in the same model.

Rahul_P1

Since this is only transformation of coordinate systems in the solver, there might be a macro for that. Did you check this?