ボルトの引張特性に及ぼす遊びねじ部の影響

抄録

ISO 898-1 is now in the course of revision, in which the tensile testing for full-size bolts using load/elongation curve will be introduced. However, the consistency of the properties obtained from the test for full-size bolts with those for the material has not fully been discussed. In this paper, the tensile test and the elastic-plastic FEM analysis were performed to clarify the effect of the free-threaded portion of a bolt on its tensile property including the issue on the stress area. Experimental results show that the free-threaded length affects the tensile properties for full-size bolts, and such behavior can be simulated by FEM analysis very well. Finally, it is clarified that the tensile property of a full-size bolt is strongly affected by the permanent strain distribution in the free-threaded portion, and hence it is advised that we should notice on this fact to specify the testing conditions and the values.