The effects of surface roughness and bond thickness on the fatigue life ofadhesively bonded tubular single lap joints

Since the surface roughness of adherends greatly affects the strength of ad hesively bonded joints, the effect of surface roughness on the fatigue life of adhesively bonded tubular single lap joints was investigated analytical ly and experimentally by a fatigue torsion test. The stiffness of the inter facial layer between the adherends and the adhesive was modelled as a norma l statistical distribution function of the surface roughness of the adheren ds. From the investigation, it was found that the optimum surface roughness of the adherends for the fatigue strength of tubular single lap joints was dependent on the bond thickness and applied load.