Multi-scale concurrent analysis for bio-inspired helicoidal CFRP laminates and experimental investigation

The bio-inspired helicoidal structure has been proved to exhibit excellent load-bearing capacity and damage resistance performance. However, there are few relevant researches to analyze its failure process from microscale. In this study, three types of carbon fiber reinforced plastics (CFRP) laminate structures were prepared-cross-ply, quasi-isotropic, and helicoidal. The mechanical performance of the laminates was tested using an indentation test. The experiment results verified the excellent mechanical performance of the helicoidal structure. In order to analyze its intrinsic enhancement mechanism, a multi-scale damage model for self-consistent clustering analysis method was proposed, and the damage evolution process of the laminates was simulated at both macro and micro scales. The results indicated that owing to the small rotation angle between adjacent layers in the helicoidal structure, the stress distribution along the thickness direction was more uniform. Moreover, the laminate was more likely to be divided into several sub-laminates by primary delamination. The fibers of each sub-laminate would be cracked in sequence from top to bottom, accompanied by the subprime delamination, resulting in the failure of the laminate. Besides, a twisted crack path could be generated, making the helicoidal structure exhibit excellent load-bearing capacity and damage resistance.

Automated summary

This study investigates the mechanical performance of a bio-inspired helicoidal structure, and finds that it exhibits excellent load-bearing capacity and damage resistance through indentation tests and simulation analysis. The small rotation angle between adjacent layers in the helicoidal structure enables a more uniform stress distribution and the generation of a twisted crack path, enhancing its load-bearing capacity and damage resistance.