ボルト・ナット結合におけるナット膨張変形

(単純引張負荷及び締付け負荷の場合の比較)

抄録

It is important to know the radial deformation (dilation) of nut in bolted joints when an axial force is applied since it affects the loadability in terms of thread stripping, fatigue strength and self-loosening. Experimental and analytical results have been reported regarding the deformation behavior of the nut when purely tensile force is applied. The behavior under a tightening load, however, has not been clarified. Therefore, in this study, a new experimental device was designed and prototyped by which both tightening load and purely tensile load can be applied to bolt/nut assembly in the joint to clarify the differences of the behavior due to the type of loading. During the experiment, it was clarified that the relative deformation between nut and measuring device causes significant error in measurement, and that the modification for fixing method of the sensors on the bolt/nut assembly is necessary. The modified device was made, and the performance is checking now.