UHARD

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

This page discusses:

Elements tested
Features tested
Problem description
Results and discussion
Input files

ProductsAbaqus/Standard

Elements tested

C3D8

C3D8T

Features tested

User subroutine to define isotropic hardening for Mises plasticity, the combined hardening material model, and porous metal plasticity.

Problem description

This set of verification problems tests many of the variables that are passed into UHARD, such as material properties, step times, and field variable increment data. These tests also verify that the user-defined quantities of yield stress and its derivatives are transferred properly to the solution process. These tests are modifications of the tests described in Rate-independent plasticity and Rate-dependent plasticity in Abaqus/Standard. For the problems selected from these sections, wherever an elastic-plastic material was defined, a user-defined hardening has been implemented in place of the corresponding keyword hardening definition. The structure being analyzed is a cube made of a single C3D8 element (or a C3D8T element when a coupled temperature-displacement procedure is tested).

Material:

Elasticity

Young's modulus, E=200.0E3

Poisson's ratio, $ν$ =0.3

Plasticity

Plasticity descriptions match those of the keyword hardening descriptions in the rate-dependent and rate-independent verification problems referenced.

Results and discussion

The tests in this section are set up as cases of homogeneous deformation of a single element of unit dimensions. Consequently, the results are identical for all integration points within the element. In each case the results match those of the referenced problem with the keyword hardening description.

Problems that test adiabatic and coupled temperature-displacement procedures have density, specific heat, and the inelastic heat fraction defined as unity and conductivity defined as zero. The resulting adiabatic temperature rise is confirmed to agree with the approximate solution determined from problems run with equivalent keyword definitions of hardening.

Input files

uhardmts.inp: Mises plasticity, uniaxial tension test. Similar to mpliho3hut.inp.
uhardmts_pormetal.inp: Porous metal plasticity, uniaxial tension test. Similar to mpliho3hut.inp.
uhardmts.f: User subroutine UHARD used in uhardmts.inp and uhardmts_pormetal.inp.
uhardmta.inp: Mises plasticity, adiabatic uniaxial tension test. Similar to mpliho3hut.inp.
uhardmta.f: User subroutine UHARD used in uhardmta.inp.
uhardmtc.inp: Mises plasticity, coupled temperature-displacement uniaxial tension test. Similar to mpliho3hut.inp.
uhardmtc_pormetal.inp: Porous metal plasticity, coupled temperature-displacement uniaxial tension test. Similar to mpliho3hut.inp.
uhardmtc.f: User subroutine UHARD used in uhardmtc.inp and uhardmtc_pormetal.inp.
uhardmss.inp: Mises plasticity, simple shear test. Similar to mpliho3gsh.inp.
uhardmss_pormetal.inp: Porous metal plasticity, simple shear test. Similar to mpliho3gsh.inp.
uhardmss.f: User subroutine UHARD used in uhardmss.inp and uhardmss_pormetal.inp.
uhardcts.inp: Mises plasticity with combined hardening, uniaxial tension with temperature and field variable dependence. Similar to mplchb2hut.inp.
uhardcts.f: User subroutine UHARD used in uhardcts.inp.
uhardrts.inp: Rate-dependent Mises plasticity, uniaxial tension test, temperature-dependent power law. Similar to mproot3hut.inp.
uhardrts_pormetal.inp: Porous metal plasticity, uniaxial tension test, temperature-dependent power law. Similar to mproot3hut.inp.
uhardrts.f: User subroutine UHARD used in uhardrts.inp and uhardrts_pormetal.inp.