Bearing-Type Bolted Hybrid Joints

The results of an analytical study of hybrid steel bolted joints of A36, A440, and A514 steel are presented. The joints were fastened by either A325 or A490 bolts. The studies were designed to determine the effect of variables on the joint strength. The major variables studied were joint length and the ratio of the net plate area, A_n, to the total fastener shear area, A_s. The studies indicated that the average shear strength of hybrid joints was equal or greater than the average shear strength of homogeneous joints. Hybrid joints behaved similarly to homogeneous joints in that as the joint length was increased, the average shear strength decreased. Also, a decrease in A_n/A_s ratio in hybrid joints was accompanied by the decrease in average shear strength experienced with homogeneous joints. Currently used (1966) design stresses were examined and it was demonstrated that increasing allowable stresses in both A325 and A490 bolts would have little effect on the minimum factor of safety in bearing-type connection.