Determining the third-order elastic constants with the thermal induced velocity change of bulk and Rayleigh wave

Abstract

This paper presents a new method to determine the third-order elastic constants (l, m, and n) using thermally induced ultrasonic bulk (longitudinal and shear) and Rayleigh wave velocity changes. The equations of relative wave velocity changes of bulk and Rayleigh waves caused by homogeneous temperature variation in an isotropic medium are presented. Two materials (Aluminum 6061 and SS304 stainless steel) were tested using the thermal modulation test and the uniaxial compression test. The measured relative velocity changes in the thermal modulation test were used to correct the temperature effect on the results of the compression test. The results show that the third-order elastic constants determined from the thermal modulation test agree with the experimental values from the uniaxial compression acoustoelastic test.