| The non-rivet connection can realize the non-auxiliary connection between different plates,with Lightweight,low cost,high efficiency,and simple process,making it one of the most promising connection technologies in the world.However,due to the large differences in performance of different types of plates,problems such as difficult connection,unstable joint quality or fracture failure,etc.occur frequently.Therefore,by studying the non-riveting joint plastic deformation mechanism of heterogeneous metal plates,formulating the reasonable joint process and designing the optimal die structure,the theoretical basis and technical reference can be provided for the non-riveting joint forming of heterogeneous metal plates.In this paper,6061 aluminum alloy and 304 stainless steel are formed without riveting connection as a research object.The model of non-riveting connection was established by using DEFORM-2D,the influence of punch diameter,die depth,groove depth,die fillet and friction coefficient on joint forming was revealed.And through the orthogonal test method to determine the best mold parameters:punch diameter Dp=5.6mm,punch radius R1=0.3mm,die diameter Dd=8.2mm,die depth H=2.0mm,groove depth h=0.8mm,die radius R2=R3=0.5mm,the groove radius is R4=0.5mm.Through the ABAQUS finite element analysis of the stress and strain of the plate and the metal flow at different deformation stages,the forming mechanism of the dissimilar metal plate without riveting connection is obtained:during the initial deformation stage,When the punch begins to press,large strain and stress are generated in the fillet transition zone of the upper and lower sheet.As the punch continues to punch,the strain of the upper sheet increases constantly,the stress of the lower sheet penetrates to the bottom and continues to increase,and the upper and lower sheets tend to deform simultaneously.Subsequently,Under the joint action of the convex and concave die,the sheet material is filled into the groove,limited by the space of the die,the flow of the sheet material is blocked,and the reflow phenomenon occurs,The upper and lower sheets are effectively interlocked and the joints are fully formed.Combining the ABAQUS/Fe-Safe finite element and performance experiments,it is obtained that:（1）The maximum tensile and shear failure loads of the joint are 1.4k N and1.8k N respectively,The main failure modes of the joint are neck fracture,trip and comprehensive failure;（2）As the tensile rate increases,the shear failure load of the joint tends to increase first and then decrease,and the maximum failure load occurs when the tensile rate is 10mm/min;（3）The fatigue life is from tension to compression in order from high to low,Undulation type,tension and compression undulation type;（4）With the increase of joint stress,the fatigue life of the joint shows a downward trend,and the damage location appears in the stress concentration area;（5）When there is residual compressive stress on the surface of the joint,the fatigue life increases;（6）The greater the stress concentration factor,the shorter the fatigue life of the joint. |
