Experimental and Theoretical Investigation of Creep Rupture of Model Structures

The creep rupture experiments were performed on a spherical shell with a radial nozzle under cyclic loading conditions, to investigate the creep rupture behavior of structures and the validity of inelastic analysis. Inconel 617 was employed as a test material and the tests were performed at 950°C. The following two methods were used to predict the rupture life of specimens. One is a finite element method. The general purpose program MARC and an in-house special purpose program for axisymmetric shells were used for calculation. The linear creep fatigue interaction rule was applied for rupture life prediction. The other is a simplified inelastic analysis method for creep rupture of structures. The collapse load and corresponding stress field obtained by the finite element computer program were employed in the simplified methods. Experimental results were compared with the calculated values. It was confirmed that the detailed and the simplified inelastic analysis methods gave reasonable prediction.