Assessment of Material Dislocation Damage by Nonlinear Ultrasound

¹ State Key Laboratory of Power System, Department of Electrical Engineering, Tsinghua University, 100084 Beijing, China
² Inspection and Research Institute, China Special Equipment, 100084 Beijing, China

^a Corresponding author: wangshen@mail.tsinghua.edu.cn

Abstract

Under harsh environment or during service, the mechanical properties of materials or structure will deteriorate. Most of the simulations exhibit the phenomenon of nonlinearity by introducing the actual small defects, without considering dislocation. In this manuscript, subroutines are written to change the mechanical constitutive behaviour of materials. When the mechanical constitutive behaviour of the material is not linear any more, it is found that the propagation of ultrasonic wave in the material will show more obvious nonlinear phenomenon. Furthermore, the nonlinear detection coefficient is used to characterize the increase of harmonic components. This work provides a new idea for nonlinear ultrasonic testing.