Description
The integrity of CFRP to steel and Fe-SMA to steel adhesively bonded structural strengthening patch must be maintained to ensure a durable application. The influence of the adhesive thickness, surface preparation, and adherend material behavior on the joint fracture has been well documented in the literature. The influence of mode-mixity has yet to be investigated and is studied experimentally and analytically in this study. Lap-shear involving mixed-mode fracture of bonded CFRP and Fe-SMA were conducted. The mode-mixity is introduced via an eccentricity between the loading axis and the adhesive plane. Furthermore, a novel theoretical model has been developed considering (i) adherend material behavior and (ii) mode-mixity. Experiments show that loading eccentricity decreases the joint capacity, up to 70% for CFRP and 32% for Fe-SMA. Analysis supported by the proposed model shows this difference is caused by the Fe-SMA material nonlinearity. The local mixity contains more Mode II in the Fe-SMA case than the CFRP. Fe-SMA yielding hinders the development of opening forces at the crack tip.
These findings hold significant meaning relative to the structural resilience and robustness of repair joint. A strengthening solution can benefit from material ductility to hinder the influence of loading eccentricity.
