Numerical Simulation And Experimental Study On Mechanical Clinching Of Dissimilar Metal Sheet

Automobile lightweight is gradually paid attention by automobile manufacturers.It is difficult to meet the requirements of safety and collision resistance of vehicles by adopting a single light alloy body.The combination of different plates can not only meet the strength requirements but also reduce the overall weight of the body.It is one of the important means to realize the lightweight of automobile,but it is difficult to realize effective connection between different kinds of plates.As a new type of cold deformation connection,mechanical clinching technology has been paid more and more attention due to its advantages of simple technology,low cost,energy saving and environmental protection.In this paper,5052 aluminum alloy and low carbon steel are taken as the research objects,and the relationship between the volume of the plate pressed by the punch and the volume of the cavity of the die is approximately equal.The volume relationship in the process of joint deformation is divided again,and the die size is redesigned,and the die parameters suitable for the connection of aluminum alloy and low carbon steel are obtained.The finite element model of mechanical clinching was established by ABAQUS software,and the forming process of mechanical clinching was numerically simulated.The deformation areas on both sides of the joint steel and aluminum were divided,and the stress state changes of each area were analyzed and compared.It was found that the forming of the interlocking structure of the joint mainly depended on the extrusion of aluminum plate and the friction constraint of the die.The metal on the aluminum side fills the concave part formed by plastic deformation on the steel side through radial flow,so as to realize interlocking.Through the analysis of the metal flow and the formation mechanism of the interlocking structure in the joint forming process,it is found that the interlocking amount and neck thickness are the two most important morphological parameters in the joint forming process.The effects of die parameters and friction coefficient on the joint morphology were studied by numerical simulation.Finally,the effective connection between aluminum alloy and low carbon steel is successfully realized through experiments.The feasibility of numerical simulation is proved by comparing the experimental and numerical simulation results.Mechanical clinching experiments were carried out on plates with different surface states,and the results were consistent with the numerical simulation results.Through the analysis of the failure mode and failure load of the joint,the importance of the joint morphology parameters to the strength is further explained,which also provides a certain theoretical basis for engineering practice.