**KCALC****KCALC**, `KPLAN`

, `MAT`

, `KCSYM`

, `KLOCPR`

**Calculates stress intensity factors in fracture mechanics analyses.**

`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. K_{II} = K_{III} = 0. Three
nodes are required on the path. |

**2**
| — | Like 1 except with antisymmetric boundary conditions
(K_{I} = 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 (K_{I},
K_{II}, and K_{III}) 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.