Investigating the effect of spew and chamfer size on the stresses in metal/plastics adhesive joints

Regarding the optimisation of adhesive lap joints, several authors have proposed the use of adhesive spews (i.e. shoulders of adhesive connecting the unloaded ends of the adherends) and of chamfers at the ends of the adherends to reduce stress concentrations. Considering a hybrid joint between steel and FRP, this paper analyses in detail the effect of such solutions on the stress field, in order to identify the optimal condition and to assess design rules. It has been found that spew and chamfer angles of about 45° are sufficient to obtain a considerable reduction of the stress peaks.