Theoretical, Experimental and Numerical Analysis of Behavior of Adhesive Bonded Joints Thin-Walled Aluminum-Composite Structures Under Axial Loading

Aluminum-composite hybrid structures have the ability to absorb high energy under crushing axial load. In this research, by using the advantages of adhesive bonding, the local reinforcement of square aluminum energy absorber has been done by composite. In this regard, a theoretical analysis has been proposed to predict the average collapse force of hybrid structures. The validity of the theoretical model has been confirmed by experimental results. In this study, four L-shaped composites are locally attached to the rectangle from inside the aluminum structure using Araldite 2015 glue. Finite element model is developed to analyze these hybrid structures. Five different modes of fiber arrangement angle [15,-15], [45,-45], [90,90], [0,90] and [0,90] are considered for the composite. Similarly, the number of composite layers varies from 2 to 8 layers. The proposed theoretical model can quickly predict the average collapse force and dissipated energy of the structure when the geometrical parameters and mechanical properties of the composite and metals are given. The results showed that compared to aluminum and aluminum-composite energy absorbers, due to the adhesive connection between aluminum and composite in the locally reinforced aluminum-composite sample, the composite absorbed energy by following the aluminum collapse pattern and creating continuous failure and collapse modes. It increased only 155.75% for aluminum and 22.99% for aluminum-composite. Among the selected cases, the optimal number of composite layers for locally reinforced aluminum-composite energy absorber is 4 layers and the optimal angle for internal reinforcement is [0,90].