High Temperature Viscoplastic Fatigue Behavior of IN-100 Using the Bodner-Partom Flow Law

摘要

Few studies have been made on the stress/strain field or plastic zone size ahead of a crack tip in a high temperature environment under varying load frequencies and stress levels. Fewer studies have incorporated compressive loads or analyzed the effect of a negative R-ratio on the fatigue characteristics of the superalloy IN-100. This study involves extending existing analysis of the stress field and plastic zone ahead of a crack tip in a compact tension specimen, through a larger number of load cycles and examining the nearly unexplored area of compressive loading of a crack in a superalloy. A USAF Materials Laboratory finite element computer program named VISCO was used for this study. The Bodner-Partom viscoplastic constitutive equations for describing the material behavior were utilized. Load spectra included various frequencies with R-ratios of 0.1 and -1.0 (zero mean load). (Author)