抄録
Sacrificial specimen is a small sized fatigue specimen which is designed so that fatigue damage may be produced in the specimen sufficiently earlier than in a structural member when it is secured onto the structural member. The purpose is to make a diagnosis of structural safety based on the monitoring result of sacrificial specimen. In the previous study, a sacrificial specimen was developed for the purpose of fatigue life prediction of structural members. In this study, a high-sensitivity sacrificial specimen is developed for the purpose of estimating the characteristics of long-term stress distribution working on structural members. In order to increase the fatigue sensitivity, a mechanism to amplify the member stress is newly applied. The sacrificial specimen is cemented onto a smooth specimen, and fatigue tests are carried out under constant stress amplitude and block loading. It is found that new sacrificial specimen can amplify the member stress appropriately and shows stable fatigue property. Further, the sacrificial specimen is applied to a structural member of actual ship. Stress monitoring is carried out during the period of fourteen months under the service condition. At the same time, stress measurement by strain gage is conducted near the sacrificial specimen. It is found that the characteristics of long-term stress distribution estimated by sacrificial specimen agrees well with that of strain gage.
