ボルト結合部の接線方向変位の挙動

正負方向に繰返し接線方向荷重が作用する場合

抄録

Deformation properties of the jointed surfaces are important in designing the machine tool structures, so in this paper considering the bolted joint as an example of jointed surfaces, the behaviour of the tangential displacement which are in close relation with the damping capacity of jointed surfaces, have been experimentally studied by applying the repeated cyclic tangential load to the jointed surface, also changing the joint materials and surface roughness. Even before the tangential displacement on a bolted joint shows a macroscopic sliding, a microslip can be found, and thereby the tangential load-displacement curve demonstrates a hysteresis loop under the repeated loading cycles, because the tangential displacement is a direct sum of the micro-slip and the tangential elastic displacement. The results obtained from this study are as follows. (1) The tangential displacement decreases with the repeated number of loading cycles, and the decreasing rate of the displacement depends on the joint materials and also on the joint surface roughness. (2) Both of the amount of the micro-slip and the tangen-tial elastic displacement increase with the increase of surface roughness. (3) The tangential elastic displacement on the jointed surfaces is, in general, in linear relation with the p=P/Q, which is the ratio of the tangential load P to the normal load Q. In addition, the tangential elastic displacement changes by the materials, surface roughness and the diameter of the jointed surface.