Dual boundary element analysis for fatigue behavior of missile structures

The fatigue behavior of a crack in a missile structure is studied using the dual boundary integral equations developed by Hong and Chen (1988). This m ethod, which incorporates two independent boundary integral equations, uses the displacement equation to model one of the crack boundaries and the tra ction equation to the other. A single domain approach can be performed effi ciently. The stress intensity factors are calculated and the paths of crack growth are predicted. In order to evaluate the results of dual BEM, four e xamples with FEM results are provided. Two practical examples, cracks in a V-band and a solid propellant motor are studied and are compared with exper imental data. Good agreement is found.