Numerical shape, thickness and stacking sequence optimisation and experimental study of hybrid composite plates under in-plane shear loading. (May 2023)

• Record Type: Journal Article
• Authors: Damghani, Mahdi; Matthews, Jason; Murphy, Adrian; Featherston, Carol
• Is Part Of: Structures. Volume 51(2023)
• Page Start: 372
• Page End: 390
• Publication Date: 2023-05
• Subjects: Free size optimisation -- Hybrid composites -- Buckling -- Post-buckling -- Shear loading; Structural engineering -- Periodicals; 624.1
• DOI: 10.1016/j.istruc.2023.03.066
• Languages: English
• ISSNs: 2352-0124

Abstract

Abstract: Shape, thickness and stacking sequence optimisation of a damage tolerant hybrid (GFRP-CFRP) composite laminate is performed using the commercial Optistruct solver. The results of the optimisation study are compared to both a benchmark non-damage tolerant CFRP laminate (without protective surface GFRP plies known as type 1 laminate) and a damage tolerant traditionally optimised hybrid CFRP-GFRP laminate (having X shape CFRP plies known as type 2 laminate), designed and tested in a previous study. The optimised laminate is manufactured using three different manufacturing techniques. The experimental buckling and post-buckling performance of the manufactured laminates are investigated. The optimised hybrid laminate is approximately 8 % heavier than the type 1 but 17 % lighter than type 2, but with the benefit of protective surface GFRP plies in favour of a damage tolerant design as shown in a previous study. Both numerical and experimental buckling and post-buckling performance studies show that the optimised laminates demonstrate higher pre-buckling stiffness compared to the type 1 design. However, the experimental buckling and failure/collapse loads, unlike the numerically predicted loads, are 24.31 % and 26.70 % lower, respectively. This is due to the significant number of ply drop-offs in the hybrid laminate design, and hence geometric imperfections and stress concentration effects at these locations leading to early buckling and failure in the post-buckling region.