Experimental investigation on the low-velocity impact responses of fibre metal laminates with various internal and external factors

• Published in: Thin-walled structures Vol. 201; p. 112004
• Main Authors: Cheng, Zheng-Qiang, Zhong, Yi-Zhi, Tan, Wei, Zhu, Zhi-Wu, Xiong, Jun-Jiang, Liu, Hu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Fibre metal laminate; Low-velocity impact; Ultrasonic C-scan; X-ray computed tomography; Low-velocity impact; Ultrasonic C-scan; X-ray computed tomography; Fibre metal laminate
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2024.112004

•The low-velocity impact responses of FMLs under different environmental temperatures are investigated experimentally.•The FMLs with unidirectional, angle-ply, cross-ply and quasi-isotropic layup sequences are considered.•The FML's damage is captured by ultrasonic C-scan, which suggests the delamination at interfaces between the composite and metal components is the main damage mechanism.•Influences of impact energy and environmental temperature are systematically investigated. This paper aims to investigate the low-velocity impact (LVI) failure mechanism of fibre metal laminates (FMLs), and systematically explore the effects of internal factors (layup sequence and laminate configuration) and external factors (impact energy and environmental temperature) on the LVI responses. The drop-weight impact tester was utilised to conduct LVI tests at -30 °C, 25 °C, and 80 °C on FML-2/1 and FML-3/2 laminates. These laminates were made of S-class high-strength glass fibre and 2024 aluminium-alloy sheet with unidirectional, angle-ply, cross-ply and quasi-isotropic layup sequences. The characteristic curves including contact force-time, contact force-deflection, absorbed energy-time, and strain-time near the dent on the impacted and non-impacted specimen surfaces were obtained respectively. Furthermore, the dent depth of the impacted surface of the FMLs was measured. FML's damage was detected by ultrasonic C-scan, and its longitudinal and transverse sections were scanned by X-ray computed tomography (CT). The findings suggest that the layup sequence has a significant effect on the LVI response of FML-2/1, but has no obvious influence on FML-3/2. Moreover, FML-3/2 exhibits greater impact resistance compared to FML-2/1. The severity of LVI damage increases with the increase of impact energy. Notably, compared to the cases at 25 °C, the LVI failure mechanisms of FMLs undergo significant changes at -30 °C. The elevated temperature of 80 °C significantly affects the LVI damage of FML-2/1, while it has no significant effect on FML-3/2.