抄録
This study aims to clarify the effect of incomplete thread of nut on the local stress acting on a bolt thread root which may affect the fatigue strength of a bolt. First, 3-D FE analysis was performed for bolts with single-start thread and with two-start thread to examine the effect of incomplete thread on the local load shared by each thread. Considering the results obtained by 3-D FE analysis, 2-D FE analysis for two types of first thread are performed to obtain local stress distribution on a thread root. The fatigue strengths for two types of bolt were calculated using the local stress and the fatigue strength of the material. Finally, it was clarified that the effect of incomplete thread of nut could not be taken into account by 2-D FE model with constant thickness of first thread. However, Local stress changes by thickness of incomplete thread.
