抄録
In this paper, low cycle fatigue characteristics of the lead free solder Sn-3.0Ag-0.5Cu material with a very sharp notch were discussed with tests at 100℃ and the numerical simulation. At the 1,000 cycle, the fatigue reduction factors β' were derived as 1.60. Inelastic numerical simulation depending on time was carried out under low cycle fatigue test conditions for lead free solder test piece with V notch with the tip radius of 30μm and 50μm at 100℃. It was shown that the depths from the bottom of the V notch with the radius of 30μm and 50μm, where calculated strain ranges agree with the low cycle fatigue life by test pieces with V notch, were almost same as the tip radius. For the life prediction, the equivalent depth from the notch bottom depends on the notch shape. However, the equivalent depth from the notch bottom was independent them the load level.
