Influence Of Die And Process Parameters On Mechanical Properties Of Steel/Aluminum Sheet Mechanical Clinching Joints

The development of new energy vehicles has drawn increasing attention to the issue of light-weighting the vehicle body.Using a steel-aluminum hybrid body is an effective solution to reduce the weight of the vehicle body.However,due to differences in their properties,the connection between steel and aluminum plates has been a long-standing issue that needs to be resolved.As a new type of cold forming connection,the mechanical clinch technology has gradually gained attention due to its simple process,low cost,energy conservation,environmental protection,and other advantages.This article takes 5052 aluminum alloy,low carbon steel,and medium carbon steel as research subjects,and designs a set of split die to facilitate the change of die depth.The overall mold is designed,and combined with universal testing machine and pressure sensors to build a mechanical clinch experimental platform,establish the entire experimental process,and successfully achieve the effective connection between aluminum alloy and steel through experiments.Establish a finite element model of mechanical clinch using ABAQUS software,and perform numerical simulation on the forming process of mechanical clinch.According to the cross-sectional topography characteristics,the forming process is divided into three stages: initial deformation,interlocking and over-extrusion.The stress and cross-sectional topography characteristics of each stage are analyzed,and the changes of cross-sectional topography parameters during the joint forming process are sorted out.Simulate the influence of material parameters,and compare the stress state and topography parameters of joints with different stacking sequences and material strength.Simulate the influence of mold parameters by changing the punch diameter and die depth,and analyze the effect of cross-sectional topography.Through experiments,the cross-sectional topography parameters of joints with different connection parameters were measured,and the credibility of the simulation results was verified.The shear strength and peel strength of joints were measured,and the influence of joint cross-sectional topography parameters and material parameters on joint mechanical properties was analyzed.The surface of steel was oxidized,and the effect of oxidation on joint topography and strength was compared.