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In recent years, the adhesive bonding method has gained increased attention, especially in the automotive industry, for constructing efficient body structures from dissimilar and lightweight materials such as aluminum and polymeric composites. Adhesively bonded automotive structures endure complicated loading conditions, including tensile and bending loading, during their service lives. To the best of the authors’ knowledge, there is no published work on the assessment of bending strength in single-lap adhesive joints (SLJs) when considering dissimilar adherends under three-point bending. In this study, three-point bend experiments were carried on the bending strength and the failure mechanisms of dissimilar SLJs made of carbon-fiber-reinforced polymer (CFRP) and aluminum substrates bonded with Araldite 2015 adhesive. Additional experiments were conducted individually on similar SLJs, including aluminum/aluminum and CFRP/CFRP, to investigate and compare the effects of adherend material type on the bending strength and failure behavior of SLJs. The results indicate that a CFRP/CFRP single-lap adhesive joint exhibits significantly higher joint strength in comparison to an aluminum/aluminum single-lap adhesive joint under three-point bending. The strength of dissimilar CFRP/aluminum single-lap joints usually falls between that of an aluminum/aluminum and that of a CFRP/CFRP single-lap adhesive joint. When the CFRP adherend is situated at the bottom of the joint in three-point bending, it imparts significantly greater joint strength and deformation compared to situations where the aluminum adherend is placed at the bottom.

Prediction of fatigue life is particularly crucial in magnetorheological elastomer (MRE) based rubber components, especially when are exposed to repetitive magnetic and cyclic loading. MREs are smart composites that contain soft elastomer matrix and carbonyl iron particles (CIPs). In this research, silicon rubber was mixed with 20% of CIPs in the absence of an external magnetic field to produce MREs. Firstly, for the determination of material constants (including hyper elastic, magnetic, and viscoelastic), two types of tests such as uniaxial compression and relaxation, were performed on the samples. Then, fatigue tests were performed by a servo-hydraulic fatigue testing machine with cyclic loading in a repetitive magnetic field. Fatigue equations were obtained based on the number of fatigue life and maximum stress. The results confirmed that maximum stress could be used as a trustworthy fatigue life predictor for MREs when they are subjected to a combination of repetitive magnetic and cyclic loading. Scanning electron microscopy images from fatigue crack showed that the internal structure of MREs became stronger in the direction of the magnetic field. The maximum stress of the MRE was smaller in the absence of a magnetic field and decreased as the number of fatigue cycles increased with and without the magnetic field. [ABSTRACT FROM AUTHOR]

Highlights 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. 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. [ABSTRACT FROM AUTHOR]