Finite element modeling and analysis of crack propagation in multiple planes of a structure

FINITE ELEMENT MODELING AND ANALYSIS OF CRACK PROPAGATION IN MULTIPLE PLANES OF A STRUCTURE An apparatus is provided for predicting propagation of a crack in a structure. A finite element model is provided that represents the layers of the structure by meshes of elements having interfaces defined between adjacent elements in orthogonal potential crack planes. Overlapping interface elements are defined at the interfaces and include a plurality of node pairs (Ni,) spaced apart along multiple interfaces and having a node cluster therebetween that includes bound node pairs. The nodes of each node pair are coincident with respective nodes of the adjacent elements on opposite sides of the interface. An analysis of the finite element model under an external load is performed in which a crack tip is established at a node cluster. A strain energy release rate between the nodes of the bound node pairs of the node cluster is calculated and based thereon propagation of the crack is identified. kt At Mk .q P, Let ._:l qw 206y INTERFACE ELEMENT 208 COINCIDENT NODES 210