Temperature correction in acoustoelastic coefficient measurements

Abstract

Acoustoelastic coefficients (AECs) of a material are used for determining third-order elastic constants (TOECs), measuring residual stress, and evaluating damage and deterioration by analyzing the change of wave velocity with stress. However, wave velocity measurements are highly sensitive to ambient or load-induced temperature changes. In this study, we proposed a temperature correction method that uses the measured temperature history and the temperature–velocity relationship of the test specimen. Acoustoelastic tests were performed in various ambient temperature conditions on three types of metals: 6063-T5 aluminum alloy (Al6063), 304 stainless steel (SS304), and 1018 low-carbon steel (S1018). Before temperature correction, the AEC measurements varied significantly, due to changes in the temperature of the specimen caused by both the ambient environment and mechanical loading. The results after the correction demonstrate that the proposed self-temperature correction method reduces temperature induced error, enabling highly accurate AEC measurements.