How do Ultrasonic waves propagate in multi-layer composites?

Many researchers take the approach of homogenizing material properties, which does not properly describe the physical behaviour, or using computationally expensive finite difference time domain (FDTD) methods. This new paper by Chirag Anand, Roger Groves and Rinze Benedictus on A Gaussian Beam Based Recursive Stiffness Matrix Model to Simulate Ultrasonic Array Signals from Multi-Layered Media published in MDPI Sensors in August 2020 takes the different approach of combining a Multi-Gaussian beam model with the recursive stiffness matrix method. We find good agreement with experimental results and we hope that this method will be useful for researchers in non-destructive inspection of thick composites, such as those found in marine applications and in wind turbines.