VUCHARLENGTH

This problem contains basic test cases for one or more Abaqus elements and features.

The following topics are discussed:

ProductsAbaqus/Explicit

Elements tested

  • C3D8
  • C3D8R
  • CAX4R
  • CPE4
  • CPE4R
  • CPS4R
  • M3D4
  • M3D4R
  • S4
  • S4R
  • S4RS
  • SAX1
  • SC8R
  • T2D2
  • T3D2

Features tested

User subroutine to define the characteristic element length to be used by Abaqus for the regularization of models that exhibit strain softening or to be passed to user subroutines that are called at the material point.

Problem description

This test verifies that the characteristic element length defined in user subroutine VUCHARLENGTH is transferred properly to built-in Abaqus material models and user subroutines that are called at the material point. The finite element model consists of multiple disconnected elements of the types listed. Each element is associated with a Mises plasticity model, and in each case a damage model is constructed using user subroutine VUSDFLD. For comparison purposes a duplicate set of elements with equivalent built-in Abaqus damage initiation/damage evolution models are included to provide a reference solution. Both the testing element and the reference element use the user-defined characteristic element length for the damage analysis. The user-defined characteristic element length is specified to be a function of nodal coordinates and the shape of the element.

Results and discussion

The initial value of the characteristic element length can be evaluated by hand calculation. The characteristic element length is stored as a solution-dependent variable in user subroutine VUSDFLD. The value of the characteristic element length in the second increment, observed in the time-history plots of solution-dependent variables, agrees with the value obtained from hand calculation. The time history plots of the other output variables in the testing element match the solution in the reference element.

Input files

damage_vucharlength.inp

Damage analysis.

damage_vucharlength.f

User subroutines VUCHARLENGTH and VUSDFLD used in damage_vucharlength.inp.