Investigation on in-plane shear behavior of large-size composite plates with multi-bolt joints

• Published in: Composite structures Vol. 232; p. 111553
• Main Authors: Zhang, Fa, Hu, Zhendong, Gao, Limin, Wan, Yumin, Jin, Limin, Jia, Xiwen, Wang, Ke, Ma, Qian
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2020
• Subjects: Composite plate; In-plane; Large size; Multi-bolt joints; Shear; Composite plate; Large size; Shear; Multi-bolt joints; In-plane
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2019.111553

This paper aims to investigate the in-plane shear behavior of large-size composite plates with multi-bolt joints. A mechanical joint structure and an universal fixture were designed and in-plane shear tests were carried out. The distributed strain gauges were used to monitor the mechanical response and ultimate bearing capacity. The failure areas and failure modes of mechanical connections were studied by ultras-scanning. A non-linear finite element model (FEM) based on 2D shell element mesh was developed to predict the load distribution and failure modes of bolt joints between composite and titanium alloys. The results show that the shear failure load reaches 365.95 kN. The shear failure occurs on the outside edges of composites plate, and the delamination extends to the vicinity of the fixture bolts. The new FEM that requires very small computational cost can evaluate the structure strength and predict destruction area. The deviation between the predicted shear failure responses and the testing results is less than 10%. The failure mode and location are consistent with the testing results, which verifies the validity of the finite element model. It suggests that this model is applicable on large scale structures and suitable to use in conjunction with iterative schemes.