Cohesive elements

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

This page discusses:

Features tested
Element kinematics
Damage modeling verification
Pressure continuity for pore pressure cohesive elements
Using cohesive elements for symmetric modeling
Miscellaneous tests

ProductsAbaqus/StandardAbaqus/Explicit

Features tested

This section provides verification for the following:

Element properties for cohesive elements.
Material and contact properties to define damage initiation.
Material properties to define damage evolution.
Use of cohesive elements in symmetric modeling.

The pressure continuity is also verified for the undamaged pore pressure cohesive elements in Abaqus/Standard.

Element kinematics

Elements tested

COH3D8

COH3D6

COH2D4

COHAX4

Problem description

The following three types of constitutive response for cohesive elements are verified in this test:

Cohesive elements used as gaskets or small adhesive patches.
A finite-thickness adhesive layer modeled using a continuum-based constitutive response.
A negligibly thin layer of adhesive modeled using a traction-separation-based response.

Each response is verified for deformation in pure normal and two pure shear modes (one shear mode for two-dimensional and axisymmetric elements) by applying appropriate displacement boundary conditions.

Model:

This test comprises single-element models, the geometry of which is defined so that the initial thickness is 1.0 for each case. The thickness direction for the elements is set to the global 1-direction, except for COH3D6, for which the thickness direction is set to the default direction.

Material:

The response of cohesive elements is tested for the following material models:

Linear elastic
Hyperelastic
Hyperfoam
Mises plasticity
Drucker-Prager plasticity

Boundary conditions:

Pure normal mode:: $u_{1}^{C}$ = $u_{1}^{D}$ = $u_{1}^{G}$ = $u_{1}^{H}$ = 1.0 $u_{1}^{A}$ = $u_{1}^{B}$ = $u_{1}^{E}$ = $u_{1}^{F}$ =−1.0
Pure shear in the first shear direction:: $u_{3}^{C}$ = $u_{3}^{D}$ = $u_{3}^{G}$ = $u_{3}^{H}$ = 1.0 $u_{3}^{A}$ = $u_{3}^{B}$ = $u_{3}^{E}$ = $u_{3}^{F}$ =−1.0
Pure shear in the second shear direction:: $u_{2}^{C}$ = $u_{2}^{D}$ = $u_{2}^{G}$ = $u_{2}^{H}$ = 1.0 $u_{2}^{A}$ = $u_{2}^{B}$ = $u_{2}^{E}$ = $u_{2}^{F}$ =−1.0

All degrees of freedom other than those listed above are fixed.

Results and discussion

The response of the cohesive elements matches the analytical results.

Input files

Abaqus/Standard input files

lk_coh3d8_ts_stack1_std.inp: TRACTION SEPARATION response for COH3D8.
lk_coh3d8_co_stack1_std.inp: CONTINUUM response for COH3D8.
lk_coh3d8_gk_stack1_std.inp: GASKET response for COH3D8.
lk_coh3d6_ts_std.inp: TRACTION SEPARATION response for COH3D6.
lk_coh3d6_co_std.inp: CONTINUUM response for COH3D6.
lk_coh3d6_gk_std.inp: GASKET response for COH3D6.
lk_coh2d4_ts_stack1_std.inp: TRACTION SEPARATION response for COH2D4.
lk_coh2d4_co_stack1_std.inp: CONTINUUM response for COH2D4.
lk_coh2d4_gk_stack1_std.inp: GASKET response for COH2D4.
lk_cohax4_ts_stack1_std.inp: TRACTION SEPARATION response for COHAX4.
lk_cohax4_co_stack1_std.inp: CONTINUUM response for COHAX4.
lk_cohax4_gk_stack1_std.inp: GASKET response for COHAX4.
coh_co_hyper_std.inp: CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperelasticity.
coh_gk_hyper_std.inp: GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperelasticity.
coh_co_hyperfoam_std.inp: CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperfoam material.
coh_gk_hyperfoam_std.inp: GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperfoam material.
coh_co_mises_std.inp: CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_gk_mises_std.inp: GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_co_dp_std.inp: CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Drucker-Prager plasticity.
coh_transshear_std.inp: COH3D8, COH3D6, COH2D4, COHAX4 with uncoupled transverse shear stiffness specified using the TRANSVERSE SHEAR STIFFNESS option.

Abaqus/Explicit input files

lk_coh3d8_ts_stack1_xpl.inp: TRACTION SEPARATION response for COH3D8.
lk_coh3d8_co_stack1_xpl.inp: CONTINUUM response for COH3D8.
lk_coh3d8_gk_stack1_xpl.inp: GASKET response for COH3D8.
lk_coh3d6_ts_xpl.inp: TRACTION SEPARATION response for COH3D6.
lk_coh3d6_co_xpl.inp: CONTINUUM response for COH3D6.
lk_coh3d6_gk_xpl.inp: GASKET response for COH3D6.
lk_coh2d4_ts_stack1_xpl.inp: TRACTION SEPARATION response for COH2D4.
lk_coh2d4_co_stack1_xpl.inp: CONTINUUM response for COH2D4.
lk_coh2d4_gk_stack1_xpl.inp: GASKET response for COH2D4.
lk_cohax4_ts_stack1_xpl.inp: TRACTION SEPARATION response for COHAX4.
lk_cohax4_co_stack1_xpl.inp: CONTINUUM response for COHAX4.
lk_cohax4_gk_stack1_xpl.inp: GASKET response for COHAX4.
coh_co_hyper_xpl.inp: CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperelasticity.
coh_gk_hyper_xpl.inp: GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperelasticity.
coh_co_hyperfoam_xpl.inp: CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperfoam material.
coh_gk_hyperfoam_xpl.inp: GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with hyperfoam material.
coh_transshear_xpl.inp: COH3D8, COH3D6, COH2D4, COHAX4 with uncoupled transverse shear stiffness specified using the TRANSVERSE SHEAR STIFFNESS option.

Damage modeling verification

Elements tested

COH3D8

COH3D6

COH2D4

COHAX4

COH3D8P

COH3D6P

COH2D4P

COHAX4P

Problem description

This test verifies damage modeling for cohesive elements using different damage initiation criteria and damage evolution laws to simulate the failure of cohesive layers. A linear elastic material model is used to verify the damage initiation criteria based on the maximum nominal strain for cohesive elements and based on the quadratic traction-interaction for cohesive elements. Damage initiation criteria based on the ductile strain and based on the shear failure strain are tested with Mises and Drucker-Prager plasticity, respectively.

Damage evolution is defined based on either effective displacement or energy dissipated. Linear, exponential, and tabular softening laws are defined to specify the nature of the evolution of the damage variable. Each damage model is verified for damage in pure normal and two pure shear modes (one shear mode for two-dimensional and axisymmetric elements). The dependence of damage evolution on the mode mix measure specified in tabular, power law, or Benzeggagh-Kenane form is also considered in this test. In addition, the test verifies the overall damage of cohesive elements when multiple damage initiation criteria are active for the same material definition.

Results and discussion

Degradation of the response of a cohesive element begins when the specified damage initiation criterion is met. The damage variable evolves according to the evolution law specified in terms of displacement or energy dissipation.

Input files

Abaqus/Standard input files

coh3d8_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH3D8.
coh3d8_qds_damdisp_softlin_std.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COH3D8.
coh3d8_mxe_damdisp_softexp_std.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_qds_damdisp_softexp_std.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_mxe_damdisp_softtab_std.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COH3D8.
coh3d8_qds_damdisp_softtab_std.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COH3D8.
coh3d8_mxe_damener_softlin_std.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COH3D8.
coh3d8_qds_damener_softlin_std.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COH3D8.
coh3d8_mxe_damener_softexp_std.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_qds_damener_softexp_std.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_nomodemix_std.inp: Damage evolution independent of mode mix for COH3D8.
coh3d8p_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH3D8P.
coh3d6_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH3D6.
coh3d6_qds_damdisp_softlin_std.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COH3D6.
coh3d6_mxe_damdisp_softexp_std.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_qds_damdisp_softexp_std.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_mxe_damdisp_softtab_std.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COH3D6.
coh3d6_qds_damdisp_softtab_std.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COH3D6.
coh3d6_mxe_damener_softlin_std.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COH3D6.
coh3d6_qds_damener_softlin_std.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COH3D6.
coh3d6_mxe_damener_softexp_std.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_qds_damener_softexp_std.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_nomodemix_std.inp: Damage evolution independent of mode mix for COH3D6.
coh3d6p_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH3D6P.
coh2d4_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH2D4.
coh2d4_qds_damdisp_softlin_std.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COH2D4.
coh2d4_mxe_damdisp_softexp_std.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_qds_damdisp_softexp_std.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_mxe_damdisp_softtab_std.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COH2D4.
coh2d4_qds_damdisp_softtab_std.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COH2D4.
coh2d4_mxe_damener_softlin_std.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COH2D4.
coh2d4_qds_damener_softlin_std.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COH2D4.
coh2d4_mxe_damener_softexp_std.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_qds_damener_softexp_std.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_nomodemix_std.inp: Damage evolution independent of mode mix for COH2D4.
coh2d4p_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH2D4P.
cohax4_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COHAX4.
cohax4_qds_damdisp_softlin_std.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COHAX4.
cohax4_mxe_damdisp_softexp_std.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_qds_damdisp_softexp_std.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_mxe_damdisp_softtab_std.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COHAX4.
cohax4_qds_damdisp_softtab_std.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COHAX4.
cohax4_mxe_damener_softlin_std.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COHAX4.
cohax4_qds_damener_softlin_std.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COHAX4.
cohax4_mxe_damener_softexp_std.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_qds_damener_softexp_std.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_nomodemix_std.inp: Damage evolution independent of mode mix for COHAX4.
cohax4p_mxe_damdisp_softlin_std.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COHAX4P.
coh3d8_coupled_multi_std.inp: COH3D8 with multiple damage models and coupled traction-separation behavior.
coh2d4_coupled_multi_std.inp: COH2D4 with multiple damage models and coupled traction-separation behavior.
coh3d8_ts_dam_loadcycle_std.inp: COH3D8 subjected to loading and unloading in pure normal (both tension and compression) and pure shear modes after partial damage.
coh2d4_damdisp_mixtrac_std.inp: Displacement-based damage evolution with traction-dependent mode mix measure for COH2D4.
coh2d4_damdisp_mixener_std.inp: Displacement-based damage evolution with energy-dependent mode mix measure for COH2D4.
coh2d4_damener_mixtrac_std.inp: Energy-based damage evolution with traction-dependent mode mix measure for COH2D4.
coh2d4_damener_mixener_std.inp: Energy-based damage evolution with energy-dependent mode mix measure for COH2D4.
coh3d8_damdisp_mixtrac_std.inp: Displacement-based damage evolution with traction-dependent mode mix measure for COH3D8.
coh3d8_damdisp_mixener_std.inp: Displacement-based damage evolution with energy-dependent mode mix measure for COH3D8.
coh3d8_damener_mixtrac_std.inp: Energy-based damage evolution with traction-dependent mode mix measure for COH3D8.
coh3d8_damener_mixener_std.inp: Energy-based damage evolution with energy-dependent mode mix measure for COH3D8.
coh_co_misesduct_std.inp: DUCTILE damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_co_misesduct_hc_std.inp: HC damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_co_misesshear_std.inp: SHEAR damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_co_dpduct_std.inp: DUCTILE damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Drucker-Prager plasticity.
coh_co_dpduct_hc_std.inp: HC damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Drucker-Prager plasticity.
coh_co_dpshear_std.inp: SHEAR damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Drucker-Prager plasticity.

Abaqus/Explicit input files

coh3d8_mxe_damdisp_softlin_xpl.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH3D8.
coh3d8_qds_damdisp_softlin_xpl.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COH3D8.
coh3d8_mxe_damdisp_softexp_xpl.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_qds_damdisp_softexp_xpl.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_mxe_damdisp_softtab_xpl.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COH3D8.
coh3d8_qds_damdisp_softtab_xpl.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COH3D8.
coh3d8_mxe_damener_softlin_xpl.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COH3D8.
coh3d8_qds_damener_softlin_xpl.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COH3D8.
coh3d8_mxe_damener_softexp_xpl.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_qds_damener_softexp_xpl.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D8.
coh3d8_nomodemix_xpl.inp: Damage evolution independent of mode mix for COH3D8.
coh3d6_mxe_damdisp_softlin_xpl.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH3D6.
coh3d6_qds_damdisp_softlin_xpl.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COH3D6.
coh3d6_mxe_damdisp_softexp_xpl.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_qds_damdisp_softexp_xpl.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_mxe_damdisp_softtab_xpl.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COH3D6.
coh3d6_qds_damdisp_softtab_xpl.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COH3D6.
coh3d6_mxe_damener_softlin_xpl.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COH3D6.
coh3d6_qds_damener_softlin_xpl.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COH3D6.
coh3d6_mxe_damener_softexp_xpl.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_qds_damener_softexp_xpl.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH3D6.
coh3d6_nomodemix_xpl.inp: Damage evolution independent of mode mix for COH3D6.
coh2d4_mxe_damdisp_softlin_xpl.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COH2D4.
coh2d4_qds_damdisp_softlin_xpl.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COH2D4.
coh2d4_mxe_damdisp_softexp_xpl.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_qds_damdisp_softexp_xpl.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_mxe_damdisp_softtab_xpl.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COH2D4.
coh2d4_qds_damdisp_softtab_xpl.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COH2D4.
coh2d4_mxe_damener_softlin_xpl.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COH2D4.
coh2d4_qds_damener_softlin_xpl.inp: QUADS damage initiation, energy-based damage evolution with LINEAR-softening for COH2D4.
coh2d4_mxe_damener_softexp_xpl.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_qds_damener_softexp_xpl.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COH2D4.
coh2d4_nomodemix_xpl.inp: Damage evolution independent of mode mix for COH2D4.
cohax4_mxe_damdisp_softlin_xpl.inp: MAXE damage initiation, displacement-based damage evolution with LINEAR softening for COHAX4.
cohax4_qds_damdisp_softlin_xpl.inp: QUADS damage initiation, displacement-based damage evolution with LINEAR softening for COHAX4.
cohax4_mxe_damdisp_softexp_xpl.inp: MAXE damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_qds_damdisp_softexp_xpl.inp: QUADS damage initiation, displacement-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_mxe_damdisp_softtab_xpl.inp: MAXE damage initiation, displacement-based damage evolution with TABULAR softening for COHAX4.
cohax4_qds_damdisp_softtab_xpl.inp: QUADS damage initiation, displacement-based damage evolution with TABULAR softening for COHAX4.
cohax4_mxe_damener_softlin_xpl.inp: MAXE damage initiation, energy-based damage evolution with LINEAR softening for COHAX4.
cohax4_qds_damener_softlin_xpl.inp: QUADS damage initiation, energy-based damage evolution with LINEAR softening for COHAX4.
cohax4_mxe_damener_softexp_xpl.inp: MAXE damage initiation, energy-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_qds_damener_softexp_xpl.inp: QUADS damage initiation, energy-based damage evolution with EXPONENTIAL softening for COHAX4.
cohax4_nomodemix_xpl.inp: Damage evolution independent of mode mix for COHAX4.
coh_co_misesduct_xpl.inp: DUCTILE damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_gk_misesduct_xpl.inp: DUCTILE damage initiation; GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_co_misesshear_xpl.inp: SHEAR damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_gk_misesshear_xpl.inp: SHEAR damage initiation; GASKET response for COH3D8, COH3D6, COH2D4, COHAX4 with Mises plasticity.
coh_co_dpduct_xpl.inp: DUCTILE damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Drucker-Prager plasticity.
coh_co_dpshear_xpl.inp: SHEAR damage initiation; CONTINUUM response for COH3D8, COH3D6, COH2D4, COHAX4 with Drucker-Prager plasticity.
coh3d8_coupled_multi_xpl.inp: COH3D8 with multiple damage models and coupled traction-separation behavior.
coh2d4_coupled_multi_xpl.inp: COH2D4 with multiple damage models and coupled traction-separation behavior.
coh3d8_ts_dam_loadcycle_xpl.inp: COH3D8 subjected to loading and unloading in pure normal (both tension and compression) and pure shear modes after partial damage.
coh2d4_damdisp_mixtrac_xpl.inp: Displacement-based damage evolution with traction-dependent mode mix measure for COH2D4.
coh2d4_damdisp_mixener_xpl.inp: Displacement-based damage evolution with energy-dependent mode mix measure for COH2D4.
coh2d4_damener_mixtrac_xpl.inp: Energy-based damage evolution with traction-dependent mode mix measure for COH2D4.
coh2d4_damener_mixener_xpl.inp: Energy-based damage evolution with energy-dependent mode mix measure for COH2D4.
coh3d8_damdisp_mixtrac_xpl.inp: Displacement-based damage evolution with traction-dependent mode mix measure for COH3D8.
coh3d8_damdisp_mixener_xpl.inp: Displacement-based damage evolution with energy-dependent mode mix measure for COH3D8.
coh3d8_damener_mixtrac_xpl.inp: Energy-based damage evolution with traction-dependent mode mix measure for COH3D8.
coh3d8_damener_mixener_xpl.inp: Energy-based damage evolution with energy-dependent mode mix measure for COH3D8.

Pressure continuity for pore pressure cohesive elements

Elements tested

COH3D8P

COH3D6P

COH2D4P

COHAX4P

Problem description

This test verifies the pressure continuity for pore pressure cohesive elements without damage.

The model contains two blocks meshed by using pore pressure solid elements. One block is on the top, while another one is on the bottom. They are connected to each other through a layer of pore pressure cohesive elements. No damage is introduced to the pore pressure cohesive elements in the tests. When different pressure is specified at the top and the bottom sides of model, the driven fluid flows smoothly across the layer of cohesive elements generating the same pressure gradient everywhere. In some tests resistance is introduced to the flow by building a filter cake by defining leak-off coefficients for pore pressure cohesive elements. In some tests the solid and cohesive elements have different mesh densities; therefore, a surface-based tie constraint will be used to connect them to each other.

Results and discussion

The smooth variation of pore pressure can be observed crossing the layer of cohesive elements.

Input files

Available only in Abaqus/Standard

coh2d4p_cont.inp: CPE4P with COH2D4P.
coh3d6p_cont.inp: C3D8P with COH3D6P.
coh3d8p_cont.inp: C3D8P with COH3D8P.
cohax4p_cont.inp: CAX4P with COHAX4P.
coh2d4p_cont_leak.inp: CPE4P with COH2D4P using FLUID LEAKOFF.
coh3d6p_cont_leak.inp: C3D8P with COH3D6P using FLUID LEAKOFF.
coh3d8p_cont_leak.inp: C3D8P with COH3D8P using FLUID LEAKOFF.
cohax4p_cont_leak.inp: CAX4P with COHAX4P using FLUID LEAKOFF.
coh2d4p_cont_tie.inp: CPE4P with COH2D4P using TIE.
coh3d6p_cont_tie.inp: C3D8P with COH3D6P using TIE.
coh3d8p_cont_tie.inp: C3D8P with COH3D8P using TIE.
cohax4p_cont_tie.inp: CAX4P with COHAX4P using TIE.

Using cohesive elements for symmetric modeling

Elements tested

COD3D8P

COD3D8PT

COH2D4

COH2D4P

COH3D8

COH3D8P

Problem description

This test verifies that symmetric models using cohesive elements generate the same results as the corresponding full models.

The full model contains two blocks meshed by using solid elements. One block is on the top, while another one is on the bottom. They are connected to each other through a layer of cohesive elements. In the symmetric models only one half of the structure is used.

Results and discussion

The results using symmetric models agree well with the results of the full models.

Input files

Available only in Abaqus/Standard

rect_coh2d4_full.inp: Full model using CPE4R with COH2D4.
rect_coh2d4_symm.inp: Symmetric model using CPE4R with COH2D4.
rect_coh2d4_half.inp: Half model using CPE4R with COH2D4.
rect_coh3d8_full.inp: Full model using C3D8R with COH3D8.
rect_coh3d8_symm.inp: Symmetric model using C3D8R with COH3D8.
rect_coh3d8_half.inp: Half model using C3D8R with COH3D8.
rect_coh2d4p_full.inp: Full model using CPE4R with COH2D4.
rect_coh2d4p_symm.inp: Symmetric model using CPE4RP with COH2D4P.
rect_coh2d4p_half.inp: Half model using CPE4RP with COH2D4P.
rect_coh3d8p_full.inp: Full model using C3D8RP with COH3D8P.
rect_coh3d8p_symm.inp: Symmetric model using C3D8RP with COH3D8P.
rect_coh3d8p_half.inp: Half model using C3D8RP with COH3D8P.
crack_coh_pipe_full.inp: Full model using cohesive elements with pipe elements.
crack_coh_pipe_symm.inp: Half model using symmetric cohesive elements with pipe elements.
crack_cod3d8pt_fp3d2t_full.inp: Full model using COD3D8PT with FP3D2T elements.
crack_cod3d8pt_fp3d2t_symm.inp: Half model using COD3D8PT with FP3D2T elements.

Miscellaneous tests

Elements tested

COD3D8P

COH2D4T

Problem description

Simple tests are created to test heat interaction, heat convection, and different fluids with gap flow.

Results and discussion

In all cases the results are as expected.

Input files

Available only in Abaqus/Standard

coh2d4t_cpe4t.inp: A coupled temperature-displacement model using CPE4T with COH2D4T.
leakoff_cod3d8p_q_p_variable_bingham.inp: A gap flow model using COD3D8P and Bingham Plastic fluid.
leakoff_cod3d8p_q_p_variable_herschel.inp: A gap flow model using COD3D8P and Herschel-Bulkley fluid.