Development of a generalized fatigue assessment approach for steel castings.

Abstract

The objective of this project was to develop a generalized fatigue assessment approach for steel castings for a range of internal casting quality details. In particular, this project examined the effect of quality details on the fatigue performance of steel castings using linear elastic fracture mechanics (LEFM) analysis. This is a research effort to address issues common in the casting industry, as current fatigue assessment approaches can be too conservative leading to overdesigned parts and the use of computationally expensive methods. The model was shown to conservatively capture experimental data in the high cycle fatigue regime using Murakami’s effective area method for quality details and LEFM estimated crack growth constants. A main outcome of this study found that the minimum indication size using an industry accessible non-destructive evaluation (NDE) technique, such as phased array ultrasonic testing (PAUT), correlated to the proposed lower limits of the LEFM fatigue design approach.