Fatigue testing is a time and resource-consuming task. Historically, SN testing was conducted at many stress levels on simple representative specimen in order to determine an SN curve, which could then be used to design a component from the same type of material. Recently, an energy-based fatigue life prediction method has been in development. The goal of this method is to quickly determine a material’s fatigue characteristics using simple test procedures. The main theory behind the energy-based fatigue life prediction method is that the strain energy in a monotonic tensile test is equal to the cumulative hysteresis energy of a cyclic test. This theory has always been tested using a single stress level on each specimen. The hysteresis loop information was then used to make fatigue life predictions at other stress levels. Further testing has been done to learn more about the hysteresis energy behavior throughout the lifetime of a specimen, but only for a single stress value. In this study, several stress levels were tested on a single specimen. This new information will help make fatigue life predictions by completely removing the difficult and inconsistent process of determining experimental curve fit coefficients traditionally used in the energy-based fatigue life prediction method.

This content is only available via PDF.
You do not currently have access to this content.