基于电磁加载的铝板残余应力在线检测方法研究

Based on the principle of acoustic elastic effects of longitudinal critically refracted (LCR) waves, non-destructive measurement of residual stress in metal can be achieved, which has broad application prospects. However, the organizational structure and the in-service environment of metal materials have a great influence on the propagation mechanism and acoustic elasticity response characteristics of critical refracting longitudinal waves, resulting in low accuracy of in-service detection of metal residual stress in engineering practice. Aiming at this problem, this paper proposed to apply electromagnetic pulling force and electromagnetic pressure to the metal plate by an electromagnetic loading device, and measured the metal acoustic elastic coefficient online. Based on the correspondence between LCR wave velocity and stress, and considering the elastic deformation of aluminum plate under the electromagnetic force, the online calculation equations of metal acoustic elastic coefficients and residual stress were derived, and the on-line detection method of metal acoustic elasticity coefficients and residual stress based on electromagnetic loading was given. Through the electromagnetic loading test of the aluminum plate, the on-line detection of the acoustic elastic coefficient and the residual stress was realized. The experimentally measured stress error value is about 4.8%, which verifies the feasibility of the on-line detection method of residual stress.