Finite element prediction of acoustoelastic effect associated with Lamb wave propagation in pre-stressed plates

Abstract

The paper presents outcomes of a finite element (FE) study of acoustoelastic effect associated with Lamb wave propagation in plates subjected to homogeneous bi-axial and bending stresses. In particular, the change of the phase velocity of the fundamental Lamb wave modes is obtained for different stress levels, bi-axial stress ratios and wave propagation angles. A comparison of the obtained numerical results with an analytical solution demonstrates a very good agreement. Moreover, the influence of bending stress on the wave velocities and wave front profile is further investigated numerically. There are currently no analytical results for this case. The developed and verified FE modelling approach can help to address several issues in the current non-destructive inspections including: in the investigation of changing stress conditions on the defect detection as well as in an adaptation of the existing Lamb wave-based defect evaluation systems to monitoring of stress too. The latter may have many benefits from sharing the same hardware for the purpose of maintaining structural integrity of thin-walled structural components.