11.4.1 Fracture mechanics: overview

ABAQUS/Standard provides the following methods for performing fracture mechanics studies:

**Onset of cracking**: The onset of cracking can be studied in quasi-static problems by using contour integrals (“Contour integral evaluation,” Section 11.4.2). The *J*-integral, the -integral (for creep), the stress intensity factors for both homogeneous materials and interfacial cracks, the crack propagation direction, and the *T*-stress are calculated by ABAQUS/Standard. Contour integrals can be used in two- or three-dimensional problems. In these types of problems focused meshes are generally required and the propagation of a crack is not studied.

**Crack propagation**: The crack propagation capability allows quasi-static crack growth along predefined paths to be studied in two-dimensional cases (“Crack propagation analysis,” Section 11.4.3). Cracks debond along user-defined surfaces. Three crack propagation criteria are available, and multiple cracks can be included in the analysis. Contour integrals can be requested in crack propagation problems.

**Line spring elements**: Part-through cracks in shells can be modeled inexpensively by using line spring elements in a static procedure, as explained in “Line spring elements for modeling part-through cracks in shells,” Section 26.10.1.