Hi,

I am new to non-linear analysis, sorry if I seem to be asking trivial questions.

I have managed to receive a negative mooney-rivlin constant when I inputted my experimental data into Solidworks. Does anyone know if this is feasible? (Compression Test, should be same as a simple tension)

Secondly, it seems that when I try to replicate the forces that exist in the experiment I conducted onto the FEA model, Solidworks gives me the error message that, "...the displacement grow larger under constant forces..." However these are the exact force values I obtained from testing. Could anyone suggest another possible issue/fix to this problem?

To note: my rubber sample is porous, and contain air gaps internally in the material. Its a mixture of recycle synthethic rubber bonded together.

Thanks for your help.