熱弾性応力測定に基づく微細粒ペーストの疲労き裂進展抑制効果の検証

Fatigue cracks have been detected in numerous infrastructures, such as steel bridges and cranes. Therefore, various repair and retrofit such fatigue cracks have been proposed. Many technical examinations and construction reports have been published who developed repair and retrofit techniques for fatigue cracks, however research reports of repair and retrofit from of non-destructive evaluation have not been published so many. We focused on fine grain paste for repair and retrofit fatigue cracks based on the reduction of stress intensity factor range. In this paper, we examined techniques to confirm retrofit treatment using the fine grain paste method. First, we studied a simple evaluation method using stress amplitude representative points near cracks. It was found that the applied fine grain paste method was effective for decelerating the growth of fatigue cracks. Further, we investigated the precise evaluation method using stress intensity factor range ΔK near the crack tip. It was found that the precise evaluation method was also effective for evaluating the fine grain paste method.