Second material for some lines

Hello,

Is there the possibility to differentiate some lines in the domain to consider a second material? I am optimising a space truss and I want diagonals to be only in compression (opposed to vertical and horizontal elements that can be in compression and tension).

Best,
Robin

Hi Robin,

At present only a single material can be allocated to a problem. We’re working on the ability to specify multiple design domains, which could include different materials, but even so I think this might not be exactly what you want for this case. It may be that we could provide line structures with a particular material property on a per-element basis, although this would need to be considered fully and developed further.

Best regards,

Tom

Hi Tom,

Thanks for your response. Indeed, having separate domains would not work for my specific application. To embed this constraint, I imagine that I need to create a N x N matrix to store the different material properties in the ground structure (N being the number of nodes). Is there a way to enforce this constraint as a post-rationalisation step, by removing the lines that should not be in tension, for instance?

Regards,
Robin

Hi Robin,

Without the ability to differentiate between tension and compression elements this isn’t achievable at the moment. If there was a process by which one could selectively remove elements in Peregrine (functionality that exists in LimitState:FORM), it may still be that the resulting solution is then unstable and the act of acquiring stability once more may re-introduce tension into the equation!

regards,

Tom

Hi Tom,

I understand, thank you for your feedback.

Best,
Robin