Nonlinear ultrasonic inspection of smart carbon fibre reinforced plastic composites with embedded piezoelectric lead zirconate titanate transducers for space applications

Abstract

Carbon fibre reinforced plastic composites used in spacecraft structures are susceptible to delamination, debonds and fibre cracking that may arise during manufacturing, assembly or in-service operations (e.g. caused by debris impacts in near-Earth orbital spaceflights). Therefore, in situ and real-time health monitoring is necessary to avoid time-consuming and unsafe visual inspections performed either on-ground or during extra vehicular activities. In this article, a recently created ‘smart’ carbon fibre reinforced plastic composite structure with embedded piezoelectric lead zirconate titanate transducers was used to detect multiple areas of artificial delamination and real impact damage of different size using nonlinear ultrasound. The electrical insulation of embedded piezoelectric lead zirconate titanate transducers was achieved by interlacing a dry layer of woven glass fibre fabric between the sensor and the carbon fibre reinforced plastic plies before curing. Damage detection was successfully demonstrated using both second harmonic generation and nonlinear modulation (sidebands) of the measured ultrasonic spectrum. The material nonlinear response at the second harmonic and sidebands frequencies was also measured with a laser Doppler vibrometer to validate the nonlinear ultrasonic tests and provide damage localisation. Experimental results revealed that the proposed configuration of embedded piezoelectric lead zirconate titanate transducers can be utilised for on-board ultrasonic inspection of spacecraft composite parts.

Optimization of a Structural Health Monitoring Systems Integration in Laminated Composite Cured in Autoclave

“…Moreover, this choice is motivated by the existence of a similar integration in the literature: Andreades and al. study [9]. Their work consists of a PZT integration into laminated composite, on the same basis of components and condition of composite curing than this present study.…”

Lead Zirconate Titanate Transducers Embedded in Composite Laminates: The Influence of the Integration Method on Ultrasound Transduction

“…To overcome such bonding layer issues under environmental conditions and also provide protection from impacts, one solution is the integration of the SHM system directly into the material. Composite materials allow the integration of a monitoring system directly into the material during manufacturing [18][19][20][21][22][23][24][25][26][27][28][29][30]. Moreover, as a co-cured surface-mounted SHM system, the manufacturing process of the composite material can be monitored directly from the beginning of the composite fabrication with an integrated SHM system [30,31].…”

“…A few recent papers have shown the use of an embedded PZT in laminate CFRP for damage detection. Andreades et al [18] reported artificial delamination and real impact damage detection with a nonlinear ultrasonic method using an embedded PZT (6 mm diameter and 0.3 mm thick) in a CFRP laminate with GFRP galvanic insulation (0.1 mm thick). Huijer et al [29] embedded PZT in a CFRP to detect the onset of damages with the method of acoustic emission monitoring.…”

On the Directivity of Lamb Waves Generated by Wedge PZT Actuator in Thin CFRP Panel

“…Such methods and the necessary tools are most in demand in manufacturing of load carrying structures, whose defects can cause emergencies or some dangerous failures. Among the known SHM and NDE methods of the polymeric composite materials the acoustic based methods are most effective and used in practice [1][2][3][4]. The common difficulties at the design of efficient acoustic based SHM of polymeric composites are the structural anisotropy of the elastic [2] and high damping properties [1,[5][6][7][8][9] of the materials that reduces the wave propagation distance [9,10].…”