How to simulate a varied stiffness model using VUMAT

Dear all,

I want to simulate a varied stiffness and elastic model in ABAQUS like this: A simple rectangular specimen, an impact load on the right side. For the sake of simplicity, supposing only shear stiffness component is strain rate dependent, for instance, it can be expressed as: Qss=a+b*log(Ess_rate), where a and b are constants, Ess_rate is shear strain rate. Now I am not sure whether this model can be implemented using VUMAT:confused::confused:. Who can help me about this issue?Thanks a million.

Best,

Haibin