ULTRASONIC SCATTERING MODELS FOR DISTRIBUTION OF CRACKS

To evaluate the initiation and growth behaviour of a distribution of cracks, an acoustic scattering model for a planar distribution of cracks is developed based on generalized reciprocity theory and Kino's scattering formalism. Subsequently, an acoustic scattering model for a linear distribution of surface cracks in the form of the local stress intensity factors is derived by using the elastostatic energy balance of crack formation. The numerical evaluation of the reflection coefficient of Rayleigh waves for a linear distribution of semi-elliptic surface cracks is subsequently performed. The results show that the reflection coefficient, varying with respect to the crack depth ratio for a linear distribution of cracks, can effectively be evaluated by using the model.