strain-displacement matrix

Hello everyone,

I have a basic question in ABAQUS. For developing a user element in ABAQUS, the strain-displacement tensor, or the so-called B-matrix, needs to be calculated in the UEL subroutine. Applying the B-matrix on the displacement vector gives rise to the strain vector. However, we know that there are more than one strain measure for corresponding, or in other words, different conjugate stress measures.

 What is here not clear for me is what type of strain tensor is calculated by applying B on the displacement vector: (eps=B.d) what is eps here?

and if this strain vector is the same vector which Abaqus provides us as input of the user material, UMAT, which is known as STRAN or in the incremental form DSTRAN?

Cheers,

Hadi