Experimental investigation of the static and fatigue behavior of hybrid ductile adhesive-RSWelded joints in a DP 1000 steel

Hybrid joining is gaining wide space in automotive industry thanks to the possibility of concentrating advantages of different joining methods in a unique technique. Producers’ main interest is indeed to obtain quality joints, which are able to maintain their properties under severe load conditions, increasing the life of their components and, thus, safety for the final users. In particular, the use of adhesive-bonding combined with resistance spot welding (RSW) offers several advantages both over adhesive joints, increasing stiffness and static strength of the assemblies, and over the welded-only joints extending fatigue life of the components. This work relates the properties of hybrid RSWeld-bonded joints in an Advanced High-Strength Steel (AHSS) to the performance of joints made by using the two joining techniques separately, i.e. spot welding only and adhesive-bonding using a semi-structural epoxy-polyurethane adhesive. The experimental findings showed that this hybrid system presents excellent static and dynamic qualities over the two more conventional techniques and also suggest its use in production.