Analysis of Stress Drop in Multistage Creep Experiments: Predictions of Exponential Creep Law

摘要

Multistage creep experiments in which the stress or temperature are increased stepwise have been successfully analyzed previously using an exponential transient creep law. The analysis is generalized and implemented for an arbitrary number of stages including stress and temperature drops. Under certain conditions, the simple exponential creep law, evaluated from data for stages following increases in stress and temperature, predicts inverted transients for stages following decreases in stress or temperature. Comparisons of predictions with limited experimental data suggest that the simple exponential creep law is inadequate, and that separate hardening and recovery processes need to be modelled to handle stress or temperature drops. (ERA citation 06:031317)