The Law of Response of LCR Wave in the Plastic and Elastic Deformation in A36 Steel

Abstract

Nowadays the method of the longitudinal critical refraction wave (LCR wave) is an effective method to nondestructively measure the on-line stress in the huge steel structures. The present study and research of the method of LCR wave are mainly focused on measuring the residual stress in the steel structures, in contrast to the few research findings related to the on-line stress measurement in steel structures (including the elastic and plastic deformation). Based on the Acoustoelastic effect, the LCR wave stress measurement system is built to measure the change of time of LCR wave propagating, stress coefficient and the energy of LCR wave in A36 steel test specimens from the elastic deformation to the plastic deformation. The conclusion is: At the free-stress condition, the flight time of LCR wave and stress coefficient show an obvious change between the elastically deformed test stage and plastically deformed stage. The change of flight time and the intensity attenuation of LCR wave show a turning point, when the specimen undergoes the process from elastic deformation to plastic deformation. And the extent of plastic deformation in the steel structure can be evaluated by the extent of intensity attenuation of LCR wave. The experimental method will be showed in this paper for measuring the extent of plastic deformation in the steel structures in service on construction scene using the LCR wave method.