kcalc

Mapdl.kcalc(kplan='', mat='', kcsym='', klocpr='', **kwargs)

Calculates stress intensity factors in fracture mechanics analyses.

APDL Command: KCALC

Parameters:

kplan

Key to indicate stress state for calculation of stress intensity factors:

0 - Plane strain and axisymmetric condition (default).

1 - Plane stress condition.

mat

Material number used in the extrapolation (defaults to 1).

kcsym

Symmetry key:

0 or 1 - Half-crack model with symmetry boundary conditions [DSYM] in the crack-tip

coordinate system. KII = KIII = 0. Three nodes are required on the path.

2 - Like 1 except with antisymmetric boundary conditions (KI = 0).

3 - Full-crack model (both faces). Five nodes are required on the path (one at the

tip and two on each face).

klocpr

Local displacements print key:

0 - Do not print local crack-tip displacements.

1 - Print local displacements used in the extrapolation technique.

Notes

Calculates the stress intensity factors (KI, KII, and KIII) associated with homogeneous isotropic linear elastic fracture mechanics. A displacement extrapolation method is used in the calculation (see POST1 - Crack Analysis in the Mechanical APDL Theory Reference). This method assumes that the displacement calculations are for the plane strain state. If the displacement calculations are performed using a plane stress formulation, the calculation of the stress intensity factors can be converted to the plane strain state by using KPLAN = 1. ANSYS Uses minor Poisson’s ratio (MP,NUXY) for the stress intensity factor calculation, therefore the material’s Poisson’s ratio must be defined using MP,NUXY command. The PATH and PPATH commands must be used to define a path with the crack face nodes (NODE1 at the crack tip, NODE2 and NODE3 on one face, NODE4 and NODE5 on the other (optional) face). A crack-tip coordinate system, having x parallel to the crack face (and perpendicular to the crack front) and y perpendicular to the crack face, must be the active RSYS and CSYS before KCALC is issued.