star stable 4 crack
Functions NINIxNIx used for the partition of unity enrichment are typically selected to coincide with the FE shape functions NIxNIx. In the variant used herein however, an alternative definition is used which has been shown [ 55, 56 ] to provide improved conditioning of the resulting stiffness matrices. More specifically, a superimposed mesh of special elements discretizing the crack front is introduced, as illustrated in Fig. 2 and the shape functions corresponding to those front elements are used as a basis for the PU enrichment.
Functions NINIxNIx used for the partition of unity enrichment are typically selected to coincide with the FE shape functions NIxNIx. In the variant used herein however, an alternative definition is used which has been shown [ 55, 56 ] to provide improved conditioning of the resulting stiffness matrices. More specifically, a superimposed mesh of special elements discretizing the crack front is introduced, as illustrated in Fig.