Abstract
This paper deals with the effect of each factor in the reinforcement on the fatigue limit of welded joint. Fatigue specimens were made by using an electrospark machining for changing only one factor of the reinforcement without leaving any residual stress, increasing hardness and so on. As the toe radius of welded joint is very small, the fatigue limit of welded joint is decided by the condition that a non-propagating crack starts to propagate. Therefore it was investigated whether the fatigue limit is given by a critical stress intensity factor or not. The stress intensity factor was calculated by use of a program of boundary element method. The following conclusions are obtained: The fatigue limit of welded joint is predictable by using a stress intensity factor. The height of reinforcement (h) does not affect the fatigue limit when h is greater than 2mm in case of plate thickness being 4mm. The effect of width in the reinforcement on the fatigue limit depends on the loading condition of fatigue test. The flank angle (θ) does not affect the fatigue limit in case of θ being greater than 60 degree.
