I intend to use a model where the instantanous response is nonlinear elastic (hyperelastic - Neo Hooke potential) and is followed with a viscoleastic response (linear model - Prony series).
It doesn't calculate a single increment and I get information about "negative eigenvalues" and heavily...
I still get an error that the system matrix has negative eigenvalues. It doesn't calculate even a single increment.
I've read thet this error message usually means that I should improve the mesh. But I quite don't know what would need an inmprovement in my case.
I use Hex, structured mesh...
Hello,
I'm doing an analisis of a feature that has small stiffness inside and big stiffness on the surface (and close to it).
I've decided to define a skin on the feature's surface and then assign a proper section to that skin (with a higher stiffness). The shell section that I have created is...
