31.4.1 An overview of the virtual crack closure technique

You can study the onset and propagation of cracking in quasi-static problems using the virtual crack closure technique (VCCT). VCCT uses the principles of linear elastic fracture mechanics (LEFM) , so it is appropriate for problems in which brittle crack propagation occurs along predefined surfaces. VCCT is based on the assumption that the strain energy released when a crack is extended by a certain amount is the same as the energy required to close the crack by the same amount.

You can include a VCCT crack in a static or quasi-static analysis procedure. Alternatively, you can include a VCCT crack in an implicit dynamic analysis procedure to simulate the fracture and failure in a structure under high-speed impact loading. VCCT is available only for Abaqus/Standard (three-dimensional solid and shell and two-dimensional planar and axisymmetric models). You can use VCCT to study a crack in parts containing geometry, orphan mesh elements, or a combination of the two. You define a VCCT crack in the Interaction module. You can specify the location of the surfaces that are initially bonded. For more information, see Modeling discontinuities as an enriched feature using the extended finite element method, Section 10.7.1 of the Abaqus Analysis User's Guide.

Creating VCCT or enhanced VCCT crack propagation models that converge to a successful solution requires some understanding of the principles behind VCCT. See Tips for using the VCCT or enhanced VCCT criterion in Abaqus/Standard” in “Crack propagation analysis, Section 11.4.3 of the Abaqus Analysis User's Guide, for information that will help you create models that can be analyzed successfully.

For detailed instructions, see Creating a VCCT crack for Abaqus/Standard, Section 31.4.2.