Improvement of Low-Temperature Strength of Composite Bonded Joints Based on Residual Plastic Strain in Adhesive Layers

Abstract

In this study, an improvement in the low-temperature strength of composite double-lap bonded joints was developed based on the residual plastic strain through preloading at room temperature. The finite element method was employed to calculate the adhesive layer stress and energy release rate between the adhesive layer and the inner adherent of the bonded joint at low temperatures. In the calculation, the residual plastic strain of the adhesive layer was considered. The numerical results indicated that the residual strain of the adhesive layer could increase the low-temperature strength of the composite bonded joints. The strength improvement of the bonded joints was experimentally evaluated at -150^ºC. From the experimental results, the low-temperature strength of the bonded joint preloaded at room temperature increased by approximately 7%.