Multiple reflection wave detection method based on inversion of multilayer material transfer function

For multi-layer composite materials, conventional ultrasonic testing is prone to interference from multiple reflected waves inside the multi-layer material due to factors such as material acoustic impedance differences and acoustic attenuation. This article proposes a new method to analyze propagation process of acoustic waves in multi-layer materials containing defects, and an algorithm for inverting the transfer function of one-layer from multiple reflection signals was proposed, and corresponding pulse responses were used to detect defects.