Mesh-free Modeling of Ultrasonic Wave Fields in Damaged Layered Half-spaces

Modeling of an ultrasonic wave field inside a layered half-space is carried out by using the mesh-free semi-analytical Distributed Point Source Method (DPSM). The complete field is computed in a layered half-space in presence and absence of defects. The layered structure is excited by a bounded ultrasonic beam generated by a finite-sized transducer. It is important to have theoretical models to predict the ultrasonic fields in damaged and damage-free structures for its nondestructive evaluation. Numerical exercises can be carried out aided by these theoretical models to determine the area of the most distorted ultrasonic field in presence of an internal anomaly. Several numerical examples are provided for an aluminum half-space attached to layers made of two different materials. The structure is excited by a bounded ultrasonic beam. Influence of the material properties and internal anomaly on the ultrasonic field pattern is demonstrated here.