The Study Of Tailor-welded Blank Square Box Deep Drawing And Weld-line Movement Based On Numerical Simulation

In recent years,Tailor welded blank(TWB)forming technology has been used more and more wildly in the automobile industry.Using this technology not only can bring huge economic benefits,but also can reduce body mass of cars and fuel consumption.It will promote the great progress of the automobile industry for the advantages of increasing body structure strength,reducing production costs,improving the body assembly precision,and increasing safety,especially in the aspect of body parts production,manufacture,design.Being similar with traditional sheet metal forming,TWB forming technology still faces many forming defects such as wrinkling,crack etc.Simultaneously,because TWB is a blank made by welding two or more single blanks together with different material type,thickness,the weld line will move adaptively along with the differences in the thickness,material properties in the two blanks on both sides of the weld,thus affecting the forming quality of TWB.Therefore,wrinkling,crack,prediction and control of the weld-line movement in the forming process of TWB need to be studied in order to enhance the property of sheet metal stamping.In this paper,The forming process of square box of steel-aluminum TWB deep drawing is simulated by the finite element analysis software Dynaform,analyzing the results of shaping.Taking mold process parameters as the main object of subject,forming depth and weld-line movement of TWB is analyzed by changing friction coefficient,die gap,the punch and die radius,corner radius.Variations of these parameters will result in the change of the speed of sheet metal flowing into the die,thus affecting the sheet metal forming resistance.The results indicate that friction coefficient,die gap,the punch and die radius,corner radius have different effects on the weld-line movement.Therefore,selecting appropriate mold process parameters can effectively avoid forming defects such as weld-line movement,wrinkling,crack,improving the stamping formability of TWBs.Finally,the methods of controlling the weld-line movement were proposed and optimized.Weld-line movement is effectively controlled by properly distributing drawbead,using split type blankholder,reducing the sheet thickness difference.