| Electromagnetic riveting(EMR)is a new kind of riveting process that the deformation of rivet can be accomplished by electromagnetic energy conversion into mechanical energy.The technology can solve the problem of insufficient riveting force.It has been widely used in the aerospace industry and will also be gradually promoted in the automotive industry.Numerical simulation and process test of electromagnetic riveting for 2A10 aluminum rivet and Q235 common carbon steel rivet are carried out based on the potential application of EMR technology in this paper.And the microstructure,mechanical properties,shear and fatigue fracture of rivet were analyzed and comparedFirstly,the loosely coupled model of electromagnetic-structure field and the sequential coupling model of force-temperature field are established respectively by finite element analysis software ANSYS and ABAQUS.The results show that the error of the punch speed and the simulation results is small,and the rivet deformation can be divided into the overall expansion of the rivet rod and the local upsetting of the upsetting head.The variation trend of magnetic pressure and discharge current shows the same attenuation distribution and the magnetic pressure reaches the peak at the 3/4 radius of the drive plate.Secondly,the riveting structure(EMR)and regular pressure riveting(RPR)of 2A10 aluminum rivets and Q235carbon steel rivets were tested for mechanical properties and microstructure and fracture analysis.The results show that the maximum shear and pull-out load of the EMR structure are higher than those of the RPR structure.The fatigue life of Q235 carbon rivet of EMR structures is 3 times higher than the RPR structure at various stress levels.The micro-topography shows that the deformation of EMR upseting head is more severe than that of RPR,and the hardness is also much higher than that of RPR.Finally,a series of schemes to replace bolt by riveting are put forward in order to explore the feasibility of rivet connection instead of bolt connection in the frame of medium and heavy truck.The connection strength and fatigue life of bolt structure and various riveted structures are studied,and the lightweight and cost analysis of the connection structure are also carried out.The riveted structure improves the shear resistance by 38.5%compared with the bolt structure,and the anti-fatigue performance of the riveted structure can be much better than that of the bolt.In addition,the riveted structure can achieve significant weight loss and reduce costs,which has practical application prospects. |
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