The Experimental Study And Numerical Simulation To The Self-piercing Riveting Of The Sheet

Self-piercing riveting is a new type of mechanical deformation to sheet metal connec- tions.It is mainly include mid-air self-piercing riveting and solid self-piercing riveting.The principle is that,in the normal temperature state, through the punch and die to squeeze piec- es of metal plates to produce plastic deformation, the realization of the mosaic panels and between the pieces complete the connection. The technology has been gradually applied in China's automobile industry, the subject of the Ministry of Education pilot research "Chu- nhui Plan" projects.In this paper, we do the following work to the mid-air self-piercing riveting:Design and processing of several different half-empty heart rivet and die to self-piercing riveting,analysis of rivets and die size of various parts of the shape of the impact of the quality of connection,in accordance with different materials, the corresponding specific heat to connecting st14 steel plate of the rivets, the half-empty heart rivet of the heat treatment process is: 840℃water quenching, tempering 450℃,and then connecting the L3 plate, the rivets do not have heat treatment, at the same time,to connect pieces to do the strength testing and comparison, L3 self-piercing riveting strength is lower than st14 self-piercing riveting.To mid-air the self-piercing riveted,make the numerically simulated to the to forming process use of finite element software LS-DYNA,obtained the equivalent field,study the trip pressure curve,boss of the die impact the closed of the connection point , pressure lap board warpage edge pieces of a great influence, analysis the various factors that affect the connection.Mid-air self-piercing riveted forming process simulation, simulation results with the actual forming process has a good consistency, simulation curves of the pressure of travel itinerary and the actual pressure curve has smaller difference.In addition, Design and processing of several different solid rivet and die to the solid self-piercing riveting,analysis of the rivet and the die size of various parts of the shape of the impact of the quality of connection. the corresponding specific heat to connecting st14 steel plate of the rivets, the solid rivets is the heat treatment process: 840℃water quench- ing, tempering 400℃,and then studied the impact of solid self-piercing riveting intensity of the main factors,the half-empty self-piercing riveting strength and solid self-piercing riveted strength were compared,the half-empty self-piercing riveting shear strength is higher than the solid self-piercing riveted shear strength. the half-empty self-piercing riveting strip strength is higher than the solid self-piercing riveted strip strength.