Time-of-flight recorded pulsed ultrasonic polar scan for elasticity characterization of composites

In its original implementation, the pulsed ultrasonic polar scan (PUPS) has been used to analyze the pulse transmission amplitudes for a wide range of oblique incidence angles with the objective of inspecting and characterizing composite materials. Recent advances and extensions proposed by the present authors, show that the analysis of the arrival time (or time-of-flight) of the transmitted pulse exhibit complementary features which may be interesting for NDT and material characterization. In the present contribution, we report on time-of flight based PUPS simulations and compare them to real high-level experimental recordings. The complementarity of the time-of-flight and the amplitude will be investigated and discussed for several materials (e.g. see figure 1 for a unidirectional carbon/epoxy). In addition, we will illustrate the relevance of the time-of-flight based PUPS for inverse characterization of the elasticity tensor of the insonified spot. Until now, the inversion schemes for the elastic material characterization were solely based on amplitude measurements. Although such inversions generally led to accurate results, special attention was needed in certain cases. In the present work, we demonstrate that accurate time-of-flight measurements allow us to upgrade the current amplitude based inversion scheme by employing a time-of-flight based inversion procedure. The first preliminary inversion results are promising.

ISBN:9781138028845

Jaar van publicatie:2015