Analysis Of Residual Stress Generation Mechanism Of Special Welded Parts And Research On Vibration Aging

Metal welding is an important production mode in industrial production.During the welding process,the heat of the base metal is extremely uneven,the temperature of the weld zone is high and the temperature varies greatly;the temperature far away from the weld zone is low and the temperature varies little,so the welding work piece will inevitably produce residual stress.The existence of welding residual stress seriously affects the mechanical properties and design life of the work piece.In this paper,the special welding parts of circular metal hoop produced in 6916 factory of PLA are taken as the research object.By combining theoretical analysis,ANSYS finite element simulation and experimental verification,the vibration aging process of the metal hoop welding parts is analyzed,the optimum clamping position of the exciter is determined,and the factory pair is improved.Vibration stress relief technology of annular metal hoop welding parts can improve the vibration stress relief and reduce the welding residual stress level.1.The generation mechanism of welding residual stress is analyzed from both macro and micro aspects;the distribution characteristics of residual stress in different welding structures are analyzed and studied based on typical welding examples;and the mechanism of reducing residual stress by vibration aging is analyzed and studied from macro and micro perspectives starting from metal tensile test.2.The three-dimensional model of welding structure is established by SolidWorks software.The typical welding process of special welding parts with ring metal hoop is selected.The temperature field and stress field are analyzed by ANSYS finite element software,which verifies and supplements the previous theoretical analysis.3.Based on the results of finite element analysis of temperature-thermal stress field,the dynamic analysis of special welding parts with ring metal hoop was carried out.The first six natural frequencies and modes of the hoop finite element model are obtained by modal analysis.Four typical different excitation positions are selected to apply the same load through harmonic response analysis technology,and the vibration response clouds of different parts of the finite element model are obtained,and the optimal clamping position of the exciter is preliminarily judged.4.According to the results of harmonic response analysis,the residual stress of welding before and after VSR was measured by blind hole method.Compared with the traditional VSR platform,the results showed that when VSR was carried out by clamping the exciter atthe outer rib of the special welding area of ring metal hoop,compared with the traditional VSR platform.The effect of vibration relief on reducing welding residual stress has been significantly improved,and this position is determined to be the best excitation position.