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

A method for predicting propagation of a crack in a structure including a plurality of layers, the method comprising:

• producing or receiving a finite element model of the structure in which the plurality of layers are represented by meshes of shell or solid elements each shell or solid element of which utilizes a collection of nodes, and the meshes of shell or solid elements having a plurality of interfaces in a respective plurality of orthogonal potential crack planes being defined between adjacent shell or solid elements of the meshes of shell or solid elements;
• defining interface elements throughout the plurality of interfaces, each interface element including a plurality of outer node pairs having a node cluster therebetween such that at least a portion of the interface element is within each respective interface of the plurality of interfaces, the nodes of each outer node pair being coincident with respective nodes of the adjacent shell or solid elements on opposite sides of the respective interface,
• wherein for each respective interface of the plurality of interfaces, each node of the node cluster is bound across the respective interface to an opposing node of the node cluster thereby being a bound node pair, the node and opposing node of the bound node pair being coincident with respective nodes of the adjacent shell or solid elements on opposite sides of the respective interface;
• and
• performing a finite element failure analysis of the finite element model under an external load, including the apparatus being caused to:
• establishing a crack having a tip located at the node cluster of the interface element;
• and
• calculating a strain energy release rate between the nodes of the bound node pairs of the node cluster under the external load;
• and in at least one instance,
• identifying propagation of the crack along the interface element based on the strain energy release rate so calculated.

A computer-readable storage medium for predicting propagation of a crack in a structure including a plurality of layers, the computer-readable storage medium being non-transitory and having computer-readable program code portions stored therein that in response to execution by a processor, cause an apparatus to at least:

• produce or receive a finite element model of the structure in which the plurality of layers are represented by meshes of shell or solid elements each shell or solid element of which utilizes a collection of nodes, and the meshes of shell or solid elements having a plurality of interfaces in a respective plurality of orthogonal potential crack planes being defined between adjacent shell or solid elements of the meshes of shell or solid elements;
• define interface elements throughout the plurality of interfaces, each interface element including a plurality of outer node pairs having a node cluster therebetween such that at least a portion of the interface element is within each respective interface of the plurality of interfaces, the nodes of each outer node pair being coincident with respective nodes of the adjacent shell or solid elements on opposite sides of the respective interface,
• wherein for each respective interface of the plurality of interfaces, each node of the node cluster is bound across the respective interface to an opposing node of the node cluster thereby being a bound node pair, the node and opposing node of the bound node pair being coincident with respective nodes of the adjacent shell or solid elements on opposite sides of the respective interface;
• and
• perform a finite element failure analysis of the finite element model under an external load, including the apparatus being caused to:
• establish a crack having a tip located at the node cluster of the interface element;
• and
• calculate a strain energy release rate between the nodes of the bound node pairs of the node cluster under the external load;
• and in at least one instance,
• identify propagation of the crack along the interface element based on the strain energy release rate so calculated.