Modeling the ultrasound reflection from immersed laminates and its application in adhesive bond inspections

Abstract

This work presents an approach for the determination of an optimal experiment design to identify faults in laminated structures immersed in acoustic fluid. The spring boundary conditions are used for the adhesive bonds and adhesion imperfections are modeled reducing the corresponding spring constants. The formulation is developed with the aid of the invariant embedding technique and, accordingly, it is numerically unconditionally stable. The frequencies/angles of incidence that are most sensitive to adhesion flaws are identified by analyzing the reflection coefficient of a healthy and a flawed plate. Such frequencies/angles of incidence are presumably the optimum choices for the inspecting field in adhesive bond ultrasound evaluations.