2.1.12 Obtaining principal stress/strain values and directions in an Abaqus/Explicit analysis

Product: Abaqus/Explicit

Reference

“VUMAT,” Section 1.2.22

Overview

Utility routines are available for calculating principal stress/strain values and principal stress/strain directions from the relevant tensors.

These utility routines are available for Abaqus/Explicit user subroutines that store stress and strain components according to the convention presented in “Conventions,” Section 1.2.2 of the Abaqus Analysis User's Guide. They are most commonly called from user subroutine VUMAT.

`VSPRINC` (calculate principal values)

Interface

      call vsprinc( nblock, s, eigVal, ndir, nshr )

Variables to be provided to the utility routine

s(nblock,ndir+nshr)

Stress or strain symmetric tensor.

nblock

Number of material points to be processed in this call to VSPRINC.

ndir

Number of direct components in the symmetric tensor.

nshr

Number of shear components in the symmetric tensor.

Variable returned from the utility routine

eigVal(nblock,I), I=1,2,3

The three principal values.

`VSPRIND` (calculate principal values and directions)