Investigation Of Geometry Characteristic And Mechanical Property Of Self-piercing Riveted Joints In AA5052

Since its excellent performance in light alloy material connection,the self-piercing riveting(SPR)process has been valued by the automotive industry and aerospace industry.As the research SPR technology in automobile manufacturing industry application prospect,AA5052 aluminum alloy sheet as the research object,based on the SPR technology for AA5052 aluminum alloy can be connectivity,form-ability and mechanical properties was studied,and focus on analysis of joints under various conditions forming performance and static performance,and connecting with the resistance spot welding connection technology,comparison and analysis from riveting connected to the resistance spot welding process of aluminium alloy in AA5052 connection characteristics and mechanical properties.The main research work summarized as follows:1.Using simulation software LS-DYNA analysis from each stage in the process of material flow and rivet riveting forming deformation characteristics,research from SPR forming process;Metallographic and micro-hardness testing,respectively study AA5052 aluminum alloy from SPR connected to the resistance spot welding forming mechanism of the punching riveting test results show that the joint forming process under large plastic deformation and strain hardening;Resistance spot welding joint show that joint metallurgical forming process the structure of the three regions and micro-hardness change,including heat affected zone is the weakest area.2.In the joints meridian plane geometry characteristics research.Research found that the thickness of the base sheet,die process parameters and the length of the rivet on joint has a great influence on the meridian plane geometry characteristics;To deal with load-displacement curve of the original data to quantitative analysis of the forming stage,determine the nail feet by Pierce into the expansion of key point;Build joint forming model,combined with simple geometric relationships determine the mathematical model of the rivet flaring.3.In the riveting head statics performance research.Substrate thickness,connection form,moulding process parameters and rivet height on the rivet head statics performance,such as joint static strength,failure modes and energy absorption value has a certain influence.Compared to two kinds of connection technique show that since the impact,riveting resistance spot welding can obtain higher static strength,including the impact riveting failure,the failure modes are pulled off tear failure modes for resistance spot welding joint surface failure.4.In the riveting head fatigue performance research.Using three parameters of the curve fitting of fatigue data processing,the results show that the impact joints fatigue performance is superior to the resistance spot welding joints;Fracture scanning shows that since the SPR failure for ductile fracture and resistance spot welding joint failure of brittle fracture.