Influence of the PZT Sensor Array Configuration on Lamb Wave Tomography Imaging with the RAPID Algorithm for Hole and Crack Detection.

Songlai Wang,Wanrong Wu,Shuai Jiang,Yiping Shen,Yi Liu

doi:10.3390/s20030860

Abstract

The tomography technique is an effective way to quantitatively evaluate damage from reconstruction imaging in structure health monitoring (SHM). The reconstruction algorithm for the probabilistic inspection of damage (RAPID) algorithm based on the signal difference coefficient (SDC) feature is a promising approach due to its superior performance. This paper focuses on the influence of different patterns of PZT (Lead Zirconate Titanate) sensor array configurations, i.e., the circular, square, and parallel array, on reconstruction image qualities for evaluating hole and crack damage. Variable shape parameters are applied to account for the unequal damage distances of different actuator-sensor pairs. Considering the directionality scattering fields of cracks, the angular scattering pattern of the SDC values are studied by simulation. The SDC variations for different groups of sensing paths at the same actuator are applied to predict the crack orientation. An improved RAPID algorithm is proposed by defining an additional SDC value of 1 in the path along the predicted crack orientation, which is determined by the point of the actuator causing the minimal SDC variation and the center point of the initial reconstruction image of the crack. The results show that the improved RAPID algorithm is effective for the evaluation of crack damage. Reconstruction image qualities with three PZT sensor array configurations for both holes and cracks are compared. The research is significant for selecting the PZT sensor array configuration in SHM.

Highlights

IntroductionLamb wave-based damage detection in plate-like structures draws increasing attention because
Lamb wave-based damage detection in plate-like structures draws increasing attention becauseLamb waves can travel over a long distance even in materials with high attenuation and which are highly susceptible to damage along the propagation path [1,2]
The objective of this paper is to explore the influences of the pattern of the PZT sensor array configuration on image quality for different types of damage, i.e., a hole and a crack

Summary

Introduction

Lamb wave-based damage detection in plate-like structures draws increasing attention because. Lamb waves can travel over a long distance even in materials with high attenuation and which are highly susceptible to damage along the propagation path [1,2]. Computerized tomography (CT) has been introduced in the Lamb-wave-based damage field and has shown great potential in quantitative damage imaging inside materials [3,4]. The superior performance of the reconstruction algorithm for the probabilistic Inspection of damage (RAPID) algorithm has been investigated through comparison with different CT algorithms [5,6]. The RAPID algorithm is based on the signal difference coefficient (SDC) feature by comparing the differences between signals with and without damage. The major advantage of the RAPID algorithm is that Lamb wave diffraction is regarded as the elliptical location probability configuration.

Objectives

Results

Conclusion