Simulation of ultrasonic array inspection of composites with side drilled holes

In this paper we ultrasonic signals from array transducers are simulated using the Thompson and Gray measurement model. The measurement model consists of a beam model, a system efficiency factor which characterizes the response of the electro-mechanical and electrical components of the system, and a flaw scattering model. To inspect layered composite structures with complex geometries such as curvature, a beam model which is non-singular is required. Hence a multi Gaussian beam model for an ultrasonic array which includes the slowness surface parameters for unidirectional CFRP is investigated. The system functions of the ultrasonic array are modelled using a system efficiency model for a rectangular array. The Kirchoff approximation and separation of variables method for far field scattering in anisotropic materials is used to model the far field response of scatterers such as side drilled holes (SDH) in unidirectional CFRP. In summary the ultrasonic measurement model developed is able to predict the signals from scatterers such as side drilled holes (SDH) in transversely isotropic CFRP.