3-D Modelling & Application Of Elemental Parabolic Crack Block -ANSYS

A 3- Dimensional Finite Element modelling was carried out to design a semi-elliptical crack surface within the block. The objective of this modelling is to create an elemental crack block which would replace the element from any other uncracked geometry and thus create a crack of arbitrary shape within the uncracked regions. A script was written to use the commercial finite element code ANSYS to design cracked geometries. The principle of the scheme is one of replacement of any 20 noded brick element in an uncracked mesh by "crack block" containing crack fronts. This automatically introduces cracks into a mesh and removes the necessity for the engineer to generate complex crack front meshes. The crack is allowed to grow through the crack -block by re-mapping the nodes of the crack block to update the crack front and maintain the history of the crack surfaces. A crack block consists of standard 20 noded isoparametric brick elements and models either a quarter circular or through crack. The crack front region is modelled by collapsed 20 noded brick elements.