Bending characteristics of partially reinforced aluminum/<scp>CFRP</scp> hybrid hat‐section beam structures with an adhesively bonded joint: An experimental, numerical, and analytical study

In this study, the axial crushing response and energy‐absorbing mechanisms of circular composite tubes, which were reinforced by carbon fiber (C10) and carbon/glass hybrids (C3G4C3), were investigated experimentally and numerically. Both samples exhibited similar crushing responses comprising delamination and intralayer shear failure. The impact kinetic energy is primarily converted into frictional and composite damage energies. C3G4C3 had poorer crashworthiness with a mean crushing force and specific energy absorption of 313.3 kN and 58.0 kJ/kg, which are by 39.3% and 30.8% less, respectively, than those of C10. The influence of glass fiber reinforced polymers (GFRP) content (hybrid ratio) and stacking sequence on tubal crashworthiness was investigated numerically. For composite tubes with a hybrid ratio of 40%, the central distribution of GFRP (C3G4C3) achieved optimal energy absorption performance. Additionally, when GFRP layers were centralized stacked, a reduction of the hybrid ratio from 60% (G3C4G3) to 20% (GC8G) helped improve the crashworthiness of the hybrid tubes, where the mean crushing force increased by 23%.Highlights Impact responses of composite tubes reinforced by carbon fiber and carbon/glass hybrids were investigated experimentally and numerically. Carbon/glass hybrid tubes exhibited lower crashworthiness. The effects of stacking sequence and hybrid ratio on the energy absorption performance were studied.

Crushing responses of carbon/glass hybrid composite tubes under dynamic compressive loads

Wang,

Chen,

Xiao

et al. 2024

On the role of local reinforcement in an adhesively bonded AL/CFRP energy absorber under axial loading: A theoretical investigation and optimization

Rahmani,

Keshavarzi,

Googarchin

2024

This paper aims to develop a novel theoretical model that incorporates the effects of local composite reinforcement using adhesive bonding on the energy absorption of aluminum structures under axial loading. The goal is to optimize energy absorption prior to any connection failures and to prevent uneven structural deformation. Moreover, it strives to reduce the structure's weight and material usage, achieving superior results compared to traditional global reinforcement techniques. The theoretical model was validated through experimental testing and finite element analysis, demonstrating good agreement with the predicted results. The results reveal that increasing the CFRP fiber angle, layer thickness, and number of layers generally leads to improved energy absorption capacity. An optimization analysis was performed to determine the optimal design parameters, yielding a fiber angle of 80°–90°, composite thickness of 1.5 mm, and aluminum thickness of 2.5 is the best configuration, offering the highest specific energy absorption and adequate peak load capacity for maximized energy absorption. The proposed model offers significant improvements over existing approaches, enhancing the predictive capabilities and practical applicability of energy absorption predictions in engineering design.Highlights A novel theoretical model for energy absorption in locally reinforced hybrid AL/CFRP structures. The influence of design parameters, such as CFRP layer count, fiber orientation, and thickness ratio. Optimization to maximize the average crushing force while meeting weight and geometric constraints. Findings can inform the design of safer and more efficient energy‐absorbing structures in various applications.

Induced structure and its gradient design on energy absorption properties and failure behavior of aluminum/carbon fiber reinforced polypropylene super hybrid tube

Huaguan,

Siyi,

Xianglong

et al. 2024

The metal/fiber super hybrid tube is a mixture of pure metal and carbon fiber structure, featuring both stable energy dissipation of the metal and good energy absorption efficiency of the composite, with greatly improved lightweight. However, the failure mode of the hybrid tube is unstable and prone to Eulerian buckling, which affects its energy absorption performance. In this work, aluminum alloy/carbon fiber reinforced polypropylene super hybrid tube (Al/CFPP super hybrid tube) have been obtained through the addition of an induced structures, which aims at reducing the maximum peak load generated during collision. The effects of induced grooves and holes structure (number of holes, diameter and row number) on the damage and energy absorption were discussed. The results showed that the initial peak load can be effectively reduced by adding an induction groove structure. When the number of induction holes is 4, the diameter is 5 mm, and the number of rows is 1, the initial peak load decreases by 14.06%, and the total energy absorption is basically unchanged. Additionally, the gradient design of the hole diameter and spacing significantly helped guide the gradual failure of the structure, with the initial peak load decreased by 21.98% and the total absorption energy increased by 20.26%.Highlights Super hybrid structures were developed to improve crashworthiness. The effect of induced grooves energy absorption was analyzed. The effect of hole size and quantity energy absorption were analyzed. A gradient design of hole size and spacing was proposed. The combined of the induction hole and trigger angle was demonstrated.