The evolution mechanisms of bearing-tension-shear failure modes of FML joints under in-plane dynamic load. (June 2022)

• Record Type: Journal Article
• Authors: Xu, Peifei; Zhou, Zhengong; Huang, Weicheng; Chen, Qiang; Lu, Fangzhou; Liu, Tianzhen
• Is Part Of: Composites communications. Volume 32(2022)
• Publication Date: 2022-06
• Subjects: Bolted FML joints -- Hybrid FML joints -- In-plane dynamic load -- Evolution of damage modes
• DOI: 10.1016/j.coco.2022.101174
• Languages: English
• ISSNs: 2452-2139

Abstract

Abstract: The quasi-static load on composite joints under normal service conditions will be transformed into in-plane impact load that is completely different from the traditional out-of-plane impact load, when the fuselage structure is threatened by dynamic impact load. The mechanical responses and damage mechanisms of bolted and hybrid (bolted/bonded) fiber metal laminate (FML) joints under high-speed tension load are investigated comprehensively. It is found that the loading velocities and adhesive layer play significant roles in determining damage pattern of bolted FML joints with specific geometric parameters. Increasing loading velocity results in the transformation of damage pattern from extended bearing-shear failure to net-tension failure in bolted joints, whose mechanisms are related to the rate dependent strength of structures. The hybrid FML joints, on the other hand, exhibit different evolution laws of damage modes due to released strain energy when the adhesive layer is damaged completely. The superposition of kinetic energy and released strain energy from adhesive layer in hybrid joints has similar effect as increasing loading velocity. The obtained conclusions provide a basis for further design of potential energy absorption joints. Graphical abstract: Image 1 Highlights: The evolution laws of failure modes of FML joints under different high-speed in-plane dynamic loads are revealed. The adhesive layer plays a significant role in the damage modes of hybrid FML joints under moderate loading velocity. The design strategies of FML joints as a novel energy-absorber are presented.