Quantitative acoustic emission and failure mechanics of composite materials

Abstract This Paper considers quantitative acoustic emission (AE) techniques with real and simulated sources as powerful tools for investigating failure processes in composite materials. Using a simulated source acting as a point source and one or more point receivers whose characteristics are known, one has the necessary components of a materials and structure testing system. Examples are shown in which a composite material's attenuation and wavespeeds can be determined as a function of frequency and propagation direction. It is demonstrated that this testing procedure permits the ultrasonic characterization of ultra-attenuative and irregular shaped, high performance composite materials. The principles of quantitative AE source characterization procedures are also reviewed and applications are demonstrated in which the time characteristics of several simple sources are recovered.