Study On Predict Technology Of Optimal Discharge Voltage In Low-voltage Electromagnetic Riveting

Electromagnetic riveting is a new type of riveting process with high-speed andhigh-energy, its riveting quality is better compared to conventional riveting process, itcan effectively solve the technical problems of riveting process in the difficult moldingmaterial or sensitive strain rate material as well as large-diameter rivets, electromagneticriveting has the characteristics of safer operation, faster riveting speed and betterriveting quality. It can greatly improve operational efficiency, and promote thedevelopment of aviation and aerospace industries. Therefore this paper studies onpredict technology of optimal discharge voltage in low-voltage electromagnetic rivetingand has important theoretical significance and practical value.This paper theoretical establish and analysis of the model of electromagneticriveting, studies the strain characteristics of the electromagnetic riveting based on theprocess of adiabatic shear, simplifies the model and established the double-loop circuitmodel of electromagnetic riveting equipment, and derives the current equations. Bysolving the mutual inductance between two ring coils, then obtains the magnetic forceequations on the driving chip, also analyzes the propagation of stress wave in a taperedamplifier by electromagnetic riveting.Based on the ANSYS software, electromagnetic field of electromagnetic riveting issimulated by the module of ASNSYS/Multiphasic. The model of electromagnetic fieldexcited by current density is established to research the impact on induced magneticfield strength by the different process parameters, and studies the method of driving thevortex repulsion into the surface electromagnetic force, also presents the specificmethods against the skin effect of driven plate, besides researches the distribution ofmagnetic pressure and the influence on discharge current and magnetic pressure bydifferent discharge parameters.Based on the ABAQUS software, the model of rivet deformation processes inelectromagnetic riveting is established and simulated, and research on the impact of thetime response parameters of rivet deformation by different discharge voltage andanalysis of the influence on the shape dimensions of upset head, rivet shank radialdisplacement and the amount of interference effects by the voltage parameters.Eventually fit data to obtain the correspondence between discharge voltage and thediameter of the upset head, and predict the optimal discharge voltage of forming size inthe upsetting rivet head by the ideal range of interference in riveting process.This paper conducts electromagnetic riveting process tests; riveted joints shearstrength tests and pull-off strength tests. Electromagnetic riveting process tests prove therationality of the relationship between the discharge voltage parameters and the upsethead forming dimensions. According to riveted joints shear strength tests and pull-off strength tests, prove that the intensity of riveted joints is close to the ideal peak by thepredicted voltage, also prove that the model of electromagnetic riveting and the methodof fitting calculation are accurate.