Creep analysis in smart single-strap adhesive joints reinforced by shape memory alloys-Experimental study

The mechanical properties of adhesive joints are very sensitive to temperature and these types of joints which are subjected to high temperature, lose their strength. Therefore, the improvement of adhesive joints' thermal resistance is highly desired. In this study, creep phenomena in single-strap adhesive joints are considered and the effect of reinforcing the joints by shape memory alloy (SMA) on the creep behavior and the lifetime of the joints are studied experimentally. The effects of temperature and wires volume fraction on the joints creep behavior are also considered. For this purpose, several single-strap adhesive joints are reinforced by SMA in the shape of wires. The epoxy used in the adhesive joints is Araldite 2015 and NiTi shape memory wires with various volume fractions ranges from 0.5% to 2% are embedded into the adhesive. The creep tests are conducted at temperatures of 100 °C, 120 °C and 135 °C which all are above the glass transition temperature of the adhesive. By using SMA wires, a significant improvement in the adhesive joints creep properties could be achieved.