Research On Self-pierce Riveting Process And Riveting Detection Mechanism Of Semi-tubular Rivets

As a rapid mechanical cold forming technology,self-piercing riveting(SPR)is suitable for connecting two or more layers,same or different materials,was widely used in the automobile industry.At present,researches on SPR of three layer aluminum are few.In this paper,test method is used to analyze the process of three-layer aluminum alloy SPR,study the static and dynamic mechanical properties of three-layer aluminum alloy riveted joints,and propose the online monitoring method of rivets failure in the riveting process.In this paper,the fixture of SPR is designed based on CMT5205 electronic universal testing machine.Which is processing,assembly and commissioning,and then complete fixture design.Thus,SPR is realized of 2-3 layers and 6-8mm aluminum alloy,which lays a solid foundation for the subsequent test.Secondly,the experimental method is used to analyze the process of SPR of threelayer aluminum alloy,and then the influence of rivet strength and length,plate strength on the force displacement curve of SPR process is studied.And a method of online detection of rivet yield and rivet pier diameter in riveting process is proposed,which based on the force displacement curve of riveting process.Then,the influence of the overlap method on the static performance of the riveted joints is studied,and it is concluded that the riveted joints with the S111 overlap method have the maximum failure load,stiffness and energy absorption value.Then the dynamic mechanical properties of the riveted joints with the S111 overlap method are studied at 0.2 ? 10 m/s five tensile-shear rates.By analyzing the maximum failure load,stiffness and energy absorption values,it can be conclude the influence of impact load with different rate on the mechanical properties of riveted joints,which will provides theoretical basis for the popularization and application of SPR.Finally,the influence of rivet failure form on the riveting process is studied.By analyzing the rivet failure form,rivet button and force-displacement curve,A method is proposed for online detection of rivet failure by force-displacement curve.