Baseline-free damage detection and sizing under varying temperatures using Lamb waves without temperature compensation

Abstract

The Lamb wave time-reversal method (TRM) has been widely proposed as a baseline-free technique for Structural health monitoring (SHM) of plate/shell-type structures. Still, its efficacy has never been tested under a variable environment. The present study examines the conventional TRM and establishes that it is unsuitable for baseline-free detection and sizing of damage under varying temperatures since the damage index (DI) is prone to change with temperature rise and generally has low sensitivity to damage. The investigation is performed for block mass-type and notch-type defects using experiments and numerical simulations. The study further tests the refined time-reversal method (RTRM), presented recently, against the same objective. This technique uses Lamb waves of the best reconstruction frequency to probe the structure, at which the reconstructed signal in a healthy plate undergoes minimum deviation from the input signal. It considers an extended wave packet for computing the DI instead of using the main mode alone. We show that this process leads to the lowest DI for undamaged plates and the highest sensitivity to damage. Also, the DI remains almost unchanged during temperature change, irrespective of the damage type, size, and plate thickness. It makes the RTRM very effective for baseline-free identification and sizing of damage under varying temperatures.

Comparative study of dynamic parameters for damage identification of carbon fiber reinforced polymer tube

“…Non‐destructive testing (NDT) techniques have been widely utilized for the detection of impact damage in composite materials. Various methods, such as acoustic emission, 5 ultrasound technology, 6 gratings, 7 Lamb waves, 8 thermal imaging, 9 and X‐rays, 10 have been employed for this purpose. These methods have found extensive application and have proven to be effective in detecting damage 11,12 .…”

Lamb Wave-Based Structural Damage Detection: A Time Series Approach Using Cointegration

“…The propagation of Lamb waves interacts with damage and can be recorded by either the same transducers (in a pulse-echo setup) or different transducers (in a pitch-catch arrangement) [16]. Damageinduced disruptions in the sensing path scatter the propagating wave, leading to alterations in the characteristics of the current Lamb wave response when compared to the original response obtained from the baseline data collected when the structure was in its undamaged Materials 2023, 16, 6894 2 of 15 state [3,16]. Lamb waves are known to be sensitive to numerous types of damage including cracks, corrosion, and delamination [4,6].…”