Experimental investigation on the influence of self-heating effect on the fatigue behavior of aluminum-CFRP riveted-bonded hybrid joints

The self-heating-induced temperature rise in the adhesive layer under fatigue loading plays a significant role in influencing the fatigue behavior of riveted-bonded hybrid joints in aluminum-carbon fiber reinforced polymer composite structures. This study aims to investigate the impact of the self-heating effect on the fatigue life of such hybrid joints. Experimental analysis was conducted to explore the interrelationships between temperature evolution and fatigue behavior at varying frequencies, adhesive thicknesses, and loading levels. Additionally, a theoretical model for predicting self-heating temperature rise in hybrid joints with different parameters was developed. Results show that the self-heating effect is notably affected by loading frequency, loading level, and adhesive thickness. The theoretical model accurately captures temperature variations and predicts critical frequencies for hybrid joints under different loading levels, which are identified as 10, 8, 3, and 1 Hz for loading levels of 35%, 40%, 50%, and 60%, respectively. Critical adhesive thicknesses ranging from 0.5 to 1 mm were also determined. Furthermore, the study predicts the fatigue life at specific self-heating temperatures with an average error within 4%, offering valuable theoretical insights for evaluating the fatigue safety performance of hybrid joints and facilitating optimization strategies. Highlights The interrelationship between the self-heating effect and fatigue behavior was revealed. Quantitative influences of main process parameters on the self-heating effect were discussed. A self-heating temperature rise model considering process parameters was developed. The critical frequency and adhesive thickness of the hybrid joint were determined.