### 4.1.1. Failure Initiation

Material Stress

  This model is useful for materials that are likely to fail along predefined material planes; for instance, where delamination failure occurs between layers in a composite plate.

  Tensile Failure Stress 11
  Tensile Failure Stress 22
  Tensile Failure Stress 33
  Maximum Shear Stress 12
  Maximum Shear Stress 23 (3D only)
  Maximum Shear Stress 31 (3D only)

  Failure is initiated if any of the principal material stresses exceed their respective tensile failure stresses. For shear failures the shear stress on planes parallel to the principal directions are checked against the maximum shear stress.

Material Strain

  This model is useful for materials, which are likely to fail along predefined material planes: For instance, where failure occurs parallel to the interface between two layers in a laminated plate.

  Tensile Failure Strain 11
  Tensile Failure Strain 22
  Tensile Failure Strain 33
  Maximum Shear Strain 12
  Maximum Shear Strain 23 (3D only)
  Maximum Shear Strain 31 (3D only)

  Failure is initiated if any of the principal material strains exceed their respective tensile failure strains. For shear failures the shear strain on planes parallel to the principal directions are checked against the maximum shear strain.

Material Stress/Strain

  This model is useful for materials that are likely to fail along predefined material planes: For instance, where failure occurs, parallel to the interface, between two layers in a laminated plate.

  Tensile Failure Stress 11
  Tensile Failure Stress 22
  Tensile Failure Stress 33
  Maximum Shear Stress 12
  Maximum Shear Stress 23 (3D only)
  Maximum Shear Stress 31 (3D only)
  Tensile Failure Strain 11
  Tensile Failure Strain 22
  Tensile Failure Strain 33
  Maximum Shear Strain 12
  Maximum Shear Strain 23 (3D only)
  Maximum Shear Strain 31 (3D only)

  Failure is initiated if any of the principal material stresses or strains exceed their respective failure levels. For shear failures the shear stresses, and strains, on planes parallel to the principal directions are checked against the inputted maximum shear stresses, and strains.

Release 18.2 - © ANSYS, Inc. All rights reserved.