Experimental investigation on the mechanical behavior of hybrid bonded (rivet/adhesive) tubular lap joint (composite to metal) under pure torsion

The hybrid joints being used in the design of mechanical structures because of their significant advantages. The tubular lap joints are used widely in aerospace, naval, and transport industries such as rudder and elevator rods, driving shafts, pull push rods, anti-roll bar and stabilizer bar in cars, trucks and trains. The torsional behavior of mechanical, adhesively bonded, and hybrid tubular lap joints for aluminum to aluminum, and composite to aluminum subjected to pure torsion have been investigated experimentally. The effect of outer tube material and thickness, the joint's type, and cured and post-cured temperature (room temperature and 40 degrees C), have been investigated experimentally. A fixture and a torsional set-up device have been designed and manufactured to apply the required torque to the joint. The outcomes from composite to aluminum joints confirm that the hybrid joint has 39.5% and 276.6% higher torque capacity than the mechanical joint and adhesively bonded joint, respectively. Furthermore, the cured and post-cured process at 40 degrees C, increased the maximum torque to failure, 37.6% and 57.1% for adhesively bonded and hybrid (rivet/bonded) joint, respectively. It has been observed that by upgrading the mechanical joint and adhesively bonded joint to the hybrid (rivet/bonded) joint, increasing the amount of joint's strength and torque capacity in comparison with the increase in the weight of the structure is affordable.