抄録
The results of fatigure testing of high strength bolts are prsented herein. And the results are presented in the S-N curue or modified goodman-diagram which are regards as the fundamental data of fatigue design for high strength bolted joints. In this paper, five different types of bolts are tested. These are F8T-M22, F10T-M22, F11T-M22, F10T-M16, F11T-M16 and are prescribed in JIS-B-1186. When a high strength bolt is subjected to a fatigue loading, for easily estimating its fatigue strength from the modified goodman-diagram, the diagram is indicated in some numerical equations. On the purpose, the author proposed one method for estimating a modified goodman-diagram by making experiments as few as possible. Comparing between experiments and the results from a proposed method, the prosperity of a proposed method is concidered. The outline of a proposed method is followings. If a modified goodman-diagram of one type of high strength bolt is obtained by experiments, making this diagram non-dimensional form by the tensile stress of the bolt, the non-dimensional modified goodman-diagram is obtained for the same diameter bolts as which are fatigue tested. And from the non-dimensional goodman-diagram, a estimated modified goodman-diagram for a bolt having the same diameter but a different tensile stress is obtained by multipling the non-dimensional modified goodman-diagram by the tensile stress of the bolt of which we want to know modified goodman-diagram. The estimated goodman-diagram according to this method is regarded as the significant and convenient data in engineering judgement.
