Abstract
For the design of mechanical structures, the fatigue limit is indispensable. Therefore, it has been developed the simple evaluation method with thermography. In this method, the temperature change can be measured for the specimen under cyclic load, and the fatigue limit is corresponding to the inflection point the temperature starts to rise rapidly. This method has been studied widely, the thermography system is used the lock-in type thermography which synchronize the signal with the cyclic load. However, it has a problem that the equipment is expensive. In this study, we performed the estimation of fatigue limit by using the non-lock-in type thermography for rotate bending fatigue testing, in particular, examines the following three points, i) the validity of applying the non-lock-in type thermography for rotate bending fatigue test, ii) determination of the inflection point in the stress-temperature change curve, iii) relationship between temperature and time.
