Mechanical APDL Structural Analysis Guide

with symmetry boundary conditions, a half-crack model with antisymmetry boundary conditions, or a
full-crack model.
Command(s):

Content to be provided.
KCALC
GUI: Main Menu> General Postproc> Nodal Calcs> Stress Int Factr

11.3.4. T-Stress Calculation

The following topics related to T-stress calculation are available:

11.3.4.1. T-Stress Interaction Integral Formulation

11.3.4.2. Element Selection and Material Behavior

11.3.4.3. Calculating the T-Stress

11.3.4.1. T-Stress Interaction Integral Formulation

The T-stress parameter is calculated using an interaction integral similar to the one used for the stress-
intensity factors calculation. The auxiliary solution used is the solution of a line load of magnitude f
applied along the crack front in the direction of the crack plane [ 12 ][ 13 ]:

11

L 3

2 2

L 2

1 2

L 2

33

L

1 3

L

2 3

ν L

In practice, the magnitude of f is typically 1.

The T-stress itself is extracted from the interaction integral result I as follows:

Τ

Ε Ι

=

( )

+











 





ν

νε

where:

T = obtained T-stress value

E = Young’s modulus

ν = Poisson’s ratio

ε 33 = ext ensional strain at the crack front in the direction tangential to the front

11.3.4.2. Element Selection and Material Behavior

T-stress evaluation (accessed via the CINT command) supports the following elements:

• PLANE182


• PLANE183


• SOLID185


• SOLID186

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Fracture Mechanics