Lamb wave-based damage detection of composite shells using high-speed fiber-optic sensing

Abstract

A Lamb wave-based damage identification method called damage imaging method for composite shells is presented. A damage index (DI) is generated from the delay matrix of the Lamb wave response signals, and it is used to indicate the location and approximate area of the damage. A piezoelectric actuator is employed to generate the Lamb waves that are subsequently captured by a fiber Bragg grating (FBG) sensor element array multiplexed in a single fiber connected to a high-speed fiber-optic sensor system. The high-speed sensing is enabled by an innovative parallel-architecture optical interrogation system. The viability of this method is demonstrated by analyzing the numerical and experimental Lamb wave response signals from laminated composite shells. The technique only requires the response signals from the plate after damage, and it is capable of performing near real-time damage identification. This study sheds some light on the application of a Lamb wave-based damage detection algorithm for curved plate/shell-type structures by using the relatively low frequency (around 100 kHz) Lamb wave response and the high-speed FBG sensor system.

Detection of multiple low-energy impact damage in composite plates using Lamb wave techniques

“…Pohl and Mook [11] used scanning laser-vibrometry to detect and investigate Lamb wave fields produced by piezoceramic actuators in CFRP plate-like structures, contributing for further clarification of propagation and interface-interaction phenomena. Sotoudeh et al [12] installed fibre Bragg grating sensors to acquire the Lamb wave response signals of curved CFRP shells excited by a piezoelectric actuator, obtaining the approximate size and location of a delamination through the damage imaging method. Liu et al [13] successfully performed a detailed numerical and experimental study of the interaction between the fundamental anti-symmetric Lamb mode (A 0 ) and a delamination in a CFRP plate, using an optimized set-up with air-coupled ultrasonic transducers.…”

Passive guided waves measurements using fiber Bragg gratings sensors

“…Another interesting possibility offered by this passive technique is to design a guided wave based SHM system with minimal intrusiveness thanks to the use of fiber Bragg grating (FBG) sensors on optical fibers. Indeed, FBG sensors have already been used as receivers of guided waves for SHM systems, but only in combination with PZT used to emit these waves (Betz , 2003;Takeda , 2005;Sotoudeh , 2014).…”