抄録
High-cycle fatigue properties until 108 cycles of non-load-carrying cruciform welded joints of JIS-SM490B rolled steel for welded structure were investigated by R=0 and σmax=σy tests which examine effects of plate thickness in welded structures. The plate thickness was 9, 20, 40, 80 and 160mm. The fatigue strengths at 108 cycles for thickness of 80 and 160mm were markedly decreased by σmax=σy test in comparison with those at 107 cycles. Therefore, fatigue limits could not be decided by fatigue strength at 107 cycles.
