The authors are investigating the joint structure that can be applied only from the upper surface of the composite deck using high strength stud bolt. The bottom steel plate is 6mm steel plate, which limits the axial force that can be introduced by the stud bolts to about half that of high-strength bolts. We focused on the tendency of friction coefficient to decrease with increasing contact pressure when the joint surface treatment is inorganic zinc. In this study, FEM was conducted to increase the slip coefficient of stud bolt friction joint by cutting around the bolt holes on the top side of the splice plate. It is found that the contact area increased and the contact pressure decreased as the splice plate cloud follow the deformation of the main plate. It is also concluded that the cutting the splice plate improved slip coefficient.
