Fatigue and Creep-Fatigue Testing of Bellows at Elevated Temperature

Fatigue and creep-fatigue tests at elevated temperature were conducted on two different-sized bellows, φ 1100 mm and φ 300 mm in nominal inner diameter, to investigate the fatigue life and the creep-fatigue interaction in a bellows, and also to provide test data for developing a life prediction method and design-by-analysis rules for bellows in elevated temperature service. A series of tests consisted of strain behavior and fatigue tests at room temperature, and fatigue and creep-fatigue tests at elevated temperature. Also, inelastic finite element analyses were performed on a bellows under internal pressure and cyclic axial deflections. Analytical results were compared with the measured data obtained in the room temperature testing to verify the strain prediction method.