Dynamic Response to Normal Stresses in a Transversely Isotropic Material Containing an External Circular Crack

The dynamic response of an external circular crack to a harmonic longitudinal wave in a transversely isotropic material is investigated using the techniques of Hankel transform. The wave impinges normally onto the crack surfaces. The inversion integral is evaluated and simplified through a complete contour integration. An exact expression for the dynamic stress intensity factor is obtained in terms of the wave frequency and the anisotropic material constants. The maximum value of the normalized dynamic stress-intensity factor is shown to occur at different wave frequencies for different sample composite and metallic materials. The dynamic effect on the crack surface displacement is also shown to be a function of the wave frequency and the material anisotropy.