Effects of low-energy impact at different temperatures on residual properties of adhesively bonded single-lap joints with composites substrates

This paper evaluates the influence of temperature, stiffness combination and impact energy on residual tensile properties of adhesive single-lap joints (SLJs) with composite substrates. High-strength steel (HSS), glass and carbon fiber reinforced plastics (GFRP and CFRP) were chosen as adherends, while Araldite® 2015 was the adhesive. The effects of four temperatures (−40, 23, 50 and 80 °C) were taken into account for the transverse impact loading with three different energy levels of 0.5, 1.5 and 2.5 J. Residual behavior and failure modes were investigated through secondary tensile tests at ambient temperature. The results indicate that impact energy and temperature both have a strong correlation with residual static properties. The degradation of mechanical strength, induced by the combined effect of low-energy impact loading and temperature, is particularly pertinent for the joints with dissimilar substrates. Furthermore, increasing the relative stiffness ratio can enhance the residual tensile strength of the SLJs with composites.