Ultrasonic non-destructive testing of plate-like structures using piezoelectric arrays transducers

Abstract

This plan proposes the study and implementation of non-destructive testing techniques of plate-like structures using piezoelectric arrays transducers and guided acoustic waves, associated with image formation and compounding methods. Damage detection in structures using guided waves and arrays is a relatively new and promising research area, specially in the aerospace and energy fields, where the use of plate-like structures, often with composite materials, demands thorough inspection due to the high safety levels of operation. Guided acoustic wave techniques can be used to inspect relatively large areas without the necessity of moving the transducers, in a non-destructive way. Furthermore they can be tuned to be sensitive to specific types of defects, like notches, delamination, surface defects. Wave propagation, interaction with defects and modes of propagation and dispersion characteristics will be studied. Finite element simulation using the software PZFlex will be used to get further insight in the theoretical aspects, and will be important as a virtual prototyping tool and to obtain dispersion curves, interaction with defects and array response. Experimental analysis will validate the simulations with isotropic materials. An important aspect of the project will be the study and implementation of piezoelectric array transducers and image formation techniques, which will be used to damage detection and characterization. The possible geometries and distribution of transducers (linear and sparse), number of elements and different apodizations with image compounding and signal processing techniques will be explored to improve the image with respect to contrast and resolution. (AU)