# About | Developments | B3 | Crack

**High Accuracy - with very few elements**

Stress intensity factors of embedded cracks and of semi-elliptical surface cracks are computed to within an accuracy of 2%-3% error using very few elements (e.g. 18 elements for a semi-elliptical crack's surfaces). Using more elements, accuracy is consistently and reproducibly improved to better than 1% error.

**Ease of use**

Accuracy is easily achieved because there is no (potentially low quality) volume mesh. Only the surface requires elements, so the volume remains free of element mesh. Cracked surfaces can be meshed with triangles or with quadrilaterals. Cracks are meshed with quadrilaterals. Compared to finite element analysis, the mesh design work for B3 cracks is minimised.

**Crack elements**

Conventional quadratic shape functions (variables: nodal displacements and tractions) with overlaid singular shape functions (variables: crack root node stress intensity factors of modes I, II, and III). The overlaid singular shape functions are global functions which extend across all elements of the crack surface.