鋼床版試験体へのき裂進展抑制工法の適用

抄録

In accordance with the aging of steel structures, fatigue of metals becomes a serious problem and countermeasures are required, because fatigue crack may lead the structure to catastrophic breakdown. “Crack growth arrester or retardation system”, developed as a versatile and high performance construction method against fatigue crack growth, by using arrester to close fatigue crack and reduce stress concentration at the fatigue crack tip. Arrester was applied to CT (Compact Tension) specimen and steel bridge deck specimen, in order to verify performance of the system and to investigate the range of application. According to the result of fatigue test using CT specimen, fatigue crack growth rate of the specimen with arrester was 2~10 times lower than that of specimen without arrester, and the threshold value of apparent stress intensity factor range was 10~20MPa√m higher than that of specimen without arrester. Specimen with stop hole required high load level to relapse fatigue crack; however, after relapse of fatigue crack, fatigue crack growth rate of the specimen with stop hole was same as that of specimen without arrester. Also, the arrester was applied to the fatigue crack which was introduced in steel bridge deck specimen. Without arrester, fatigue crack extended in accordance with the increase of loading cycles, on the other hand, fatigue crack growth stopped after construction of the arrester.