**i_integral

Description

This option calculates the \(T\) stress using the method of Chen et al. [U7]. and DeLorenzi [U8]. The implementation is similar to the **j_integral_lorenzi in its use of a virtual crack extension.

Syntax

**i_integral \(~\,~\,\) perturb ( elset | tip ) (name1  node_num) \(~\,~\,\) da (dax day) \(~\,~\,\) \(~\,~\,\) tip nset \(~\,~\,\) young E \(~\,~\,\) poisson nu \(~\,\) [ factor f ]

da (dax day)

to indicate the crack direction (and not the crack growth direction !).

tip nset

indicates the node corresponding to the tip

young E

gives the Young’s modulus

poisson nu

gives the Poisson’s ratio

factor f

indicates a multiplicative factor to be used in the case of symmetries. Default value is 1.

The \(T\)-stress calculations works with small deformation plane stress and plane strain elements. Like for the deLorenzi or Parks methods, the syntax perturb elset next will search the next elset surrounding the crack tip. This syntax can be repeated.