i am implementing progressive failure of composites in a umat.
For the moment i am limited to static simulations, and everything seems fine when dealing with single element verification.
Now I’d like to perform more complex virtual tensile tests in a *DYNAMIC framework.
From what i understand, only an initial velocity can be applied to a node set through an initial condition; this is ok to perform impact like simulation. But it seems that no velocity boundary conditions or non-zero BC is allowed in this framework, which means that i can not perform a tensile test where i impose the velocity of one sample extremity while keeping the other fixed.
Is my understanding correct and do you see a potential workaround ?
The first part is right - there are no velocity or acceleration BCs in CalculiX (apart from acceleration base motion for linear dynamics) but why would the latter be the case ? You can have non-zero displacement BCs in nonlinear dynamic (*DYNAMIC) steps. You should just use some amplitude to set their time variation properly.
hello, actually, it is working fine with the built in orthotropic linear elastic material.
However, when i use a user material, it does not seem to compute properly the stable time increment.
Any know limitation of user materials within a dynamic explicit step ?
Thanks again for your help
Regards