Modeling of ultrasonic nonlinearities for debris cloud-induced micro-voids characterization : theoretical analysis and numerical validation

Abstract

Micro-damage, from dimples through micro-voids to micro-cracks, are formed underneath the pitting damage due to the debris cloud hypervelocity impact (HVI). Evaluation of this specific type of micro-damage is far beyond the detectability of conventional approaches using guided ultrasonic waves (GUWs), because the large number of micro-voids in the pitting damage region cause highly complex. Targeting the quantitative characterization of these micro-voids, an analytical model is developed to interpret the generation of high-order modes when a GUW traversing from the perspective of linear and nonlinear GUW features. Validation of this theoretical analysis is ascertained via numerical simulation. On this basis, an evaluation framework is developed whereby the micro-voids can be quantitatively depicted.