2.2. Fracture-Parameter Calculation Element and Material Support

The following elements and materials/loads support fracture-parameter calculation:

Table 2.1: Element Support for Fracture-Parameter Calculation

Element Type Description Parameter Calculations Supported

PLANE182 [a]

2D 4-Node Structural Solid

PLANE183 [a]

2D 8-Node or 6-Node Structural Solid

SOLID185 [b]

3D 8-Node Structural Solid

SOLID186 [b]

3D 20-Node Structural Solid

SOLID187

3D 10-Node Tetrahedral Structural Solid

SOLID285

3D 4-Node Tetrahedral Structural Solid with Nodal Pressures

[a] KEYOPT(3) > 3 is not supported. For plane stress elements (KEYOPT(3) = 3), the varying-thickness option is not supported.

[b] KEYOPT(3) = 1 is not supported.


Table 2.2: Material and Load Support for Fracture-Parameter Calculation

  Fracture ParameterMaterial Models SupportedLoad Types Supported
FEM J-integral

  • Linear isotropic elasticity

  • Isotropic plasticity

  • Crack-surface traction

  • Body force[a]

  • Temperature

  • Initial strain

  • Initial stress[b]

  • Crack-surface traction (derived from initial stress)[c]

Stress-intensity factors

  • Linear isotropic elasticity

  • Crack-surface traction

  • Body force[a]

  • Temperature

  • Initial strain

  • Initial stress[b]

  • Crack-surface traction (derived from initial stress)[c]

T-stress

  • Linear isotropic elasticity

  • Temperature

C*-integral

  • Secondary (steady-state) creep material

  • Crack surface pressure

  • Temperature

VCCT

  • Linear isotropic elasticity

  • Orthotropic elasticity

  • Anisotropic elasticity

  • Crack surface pressure

  • Body force[a]

  • Temperature

Material force

  • Linear isotropic elasticity

  • Isotropic hardening plasticity

  • Kinematic hardening plasticity

  • Isotropic hyperelasticity

  • Crack surface pressure

  • Temperature

Singularity-Based XFEM J-integral

  • Linear isotropic elasticity

  • Temperature

Stress-intensity factors

  • Linear isotropic elasticity

  • Temperature

T-stress Not available --
C*-integral --
VCCT --
Material force --

[a] Includes gravity and centrifugal body forces with commands ACEL, OMEGA, CMOMEGA, CMACEL, CGLOC, CGOMGA. For information about applying gravity and centrifugal body forces, see the documentation for those commands.

[b] The program transforms initial stresses internally to initial strains for fracture-parameter calculation.

[c] An alternate approach to incorporate any residual (initial) stress for fracture analysis. The program automatically applies a crack-surface traction load equivalent to the specified initial-stress field. Figure 2.2: Superposition Principle: Initial Stress vs. Crack-Face Traction establishes that an equivalent crack-surface traction load leads to the same fracture parameters in the linear elastic regime. See CINT,CSFL for more information.


Figure 2.2: Superposition Principle: Initial Stress vs. Crack-Face Traction

Superposition Principle: Initial Stress vs. Crack-Face Traction