In Abaqus, how to get SSE in UMAT?

Hi all,

I have been writing a UMAT function with modified hyper-visco-elastic model. My question is: after I got the Cauchy stress at the end of step, how do I get the SSE （elastic strain energy density)?

If it is only hyper-elastic I would have known (since the strain energy function itself is given). However, if it is viscoelastic, how should I calculate?

PS: I would also appreciate it if anyone could shed some light in getting SPD, SCD as well. Thanks a lot!

-Shawn