Crack Initiation/Propagation of Perforated Plate Under Displacement-Controlled Creep-Fatigue Test at Elevated Temperature

In structures having stress concentration under cyclic and holding loading, a small crack initiates and it grows and propagates. The present paper shows the experimental results of the perforated plate having the different diameters and the prescribed different strain amplitude. In the specimens having a circular hole, a crack initiates at the hole side having the most severe stress concentration in the specimen, and then the other crack also starts to initiate at the opposite hole side. Growth of both cracks is observed from the photographs taken at each cycle to study the relation between crack growth and load decrease. The feature of crack growth initiating of creep-fatigue test from multiple origins will be discussed for those of fatigue test.