Abstract
The effect of the plain washer's thickness on the contact stress distributions and the plastic displacements (permanent set) at the bearing surfaces are analyzed using elasto-plastic FEM analyses in case of the initial bolt clamping state. It is found that the contact stress and the plastic deformation decrease as the thickness of washer increases. It is shown that the plastic displacements at the bearing surfaces in case of hexagon bolts with flanges are smaller than in case of hexagon head bolts. Also even if the average contact stress is the same at the bearing surface, the plastic displacements are smaller in case of smaller bolt holes of clamped parts.
