Nonliear Geometry

Dear Colleagues,

I have done some analysis with nonlinear geometry. I use quadratic 3D solid elements. I have learned the way to calculating DSTRAN and DROT from ABAQUS documentation as follows:

ΔF*F (t)= F (t+dt)ΔF=ΔV*ΔR

DSTRAN=ln(ΔV)

DROT=ΔR