Assessment of damage in composites using static component generation of ultrasonic guided waves

Abstract

Static component (SC) generation of guided waves (GWs), which combines the high sensitivity of acoustic nonlinearity to micro-damage and low attenuative effect, has great potential for damage assessment in large composite structures. The present work explores the use of SC generation of GWs for assessing damages in carbon fiber reinforced polymer (CFRP) composite laminates. The features including mode, waveform, and cumulative effect of the generated SC in composites are numerically investigated by three-dimensional finite element modeling and simulation. A dynamic displacement measurement method based on piezoelectric transducers is accordingly proposed and experimentally verified. The cumulative SC pulse generated from primary GW tone-burst with a finite duration, is observed and verified numerically and experimentally. It is found that the magnitude of the generated SC pulse is linearly proportional to the quadratic material nonlinearity. Experimental results demonstrate that the generated SC pulse of GW under group velocity matching condition, is an effective means to assess the hygrothermal damage and low-velocity impact damage in CFRP composite plates. The performed experimental examination validates the feasibility of the proposed approach for damage assessment in CFRP composites.

Assessment of thermal damage in polymethyl methacrylates using quasi-static components of ultrasonic waves

“…According to previous theoretical, numerical, and experimental studies [21][22][23][24][25][26]31], the QSC generation of ultrasonic waves can be taken as an effective index for evaluating the material nonlinearity. Meanwhile, it is known that the time-domain signal of the QSC generated by ultrasonic wave tone burst with finite duration has an envelope-like temporal shape regarding the primary wave packet [31]. The carrier frequency of the generated QSC pulse is equal to zero, which enables it to propagate over longer distances in the specimen than higher harmonics.…”

A novel pulse-echo piezoelectric transducer for detecting quasi-static component induced by an ultrasonic longitudinal wave

“…Deng proposed a pitch-catch based method for measuring QSC [11], where a low-frequency piezoelectric transducer was used to directly detect the QSC pulse generated by the propagation of the high-frequency PLW tone burst. In order to obtain a good response of the generated QSC pulse, the frequency spectrum of the low-frequency piezoelectric transducer needs to adequately overlap with the main lobe of the frequency spectrum of the generated QSC pulse [5,11]. This can readily be achieved by appropriately adjusting the cycles of the PLW tone burst.…”

“…Compared with the second-harmonic generation, the generated QSC has advantages of less attenuation, longer propagation distance, and the cumulative growth effect without the requirement of phase velocity matching condition. Therefore, these advantages make it to have a potential to become an attractive option for the early-stage damage evaluation of structures and considerable research efforts have been devoted to it over the past few decades [4][5][6][7].…”

Research on nonlinear ultrasonic method for evaluating the mechanical properties of 3D printing aluminum alloy

“…Nonlinear ultrasonic NDT technologies focus on the analyses of the generated waves to evaluate the material damage/degradation in the early stage. Jiang et al and Li et al proposed a novel nondestructive method for damage assessment in composite by using quasi-static components generation of ultrasonic waves, which provides a promising means for highly attenuating or strong scattering materials with great potential [25][26][27]. Cantrell and Yost [28] studied the correlation between dislocation density levels within the fatigued aluminum alloy 2024-T4 and an increase in harmonic ultrasonic signals.…”