Numerical Simulation Of Multi-point Forming Of Sheet Metal With Flexible Blank-holder

Sheet metal forming technology has been occupied an important position in themanufacturing industry. As the sheet metal forming applications in various industries areincreasingly mature, people also try to improve the sheet manufacturing process. However,the traditional varieties of processing method is difficult to adapt to many varieties of smallbatch production because its production preparation cycle is too long and has a highcost.Therefore, a forming technology with highly flexible and highly efficient way of nomold forming gradually become the main trend of development of stamping technology andequipment in the world. At the same time, the3-d surface large deformation partsprocessing forming is got more and more people’s attention.This kind of parts have a bigrequriment to machining methods and forming quality. Therefore, the forming method withflexible blank-holder in multi-point forming (MPF) have started to be used in dailyproduction and manufacturing life. This kind of method has a great superiority comparedwith the traditional way of rigid blank holder.In this study, the wrinkle and flaw are studied when shaped in rigid blank holder andflexible blank-holder. At the same time, the comparison and analysis of sheet formingquality and flexiblity of blank-holders are made when shaped with flexible blank holderapplying uniform and non-uniform blank-holder force by setting up two models of rigidand flexible blank-holder.The influence on the quality of blank is made by analysisingthickness of the sheet,the material of the sheet,the thickness of the blank-holder. the Usingimplycit calculation method to calculate the sheet springback amount under the threeforming modes and making a longitudinal comparison of the rigid and flexible blankholderof the sheet in springback amount,at the same time,making a horizontal comparison of theflexible blank-holder way to uniform and non-uniform blank-holder force in springback amount.In conclusion,the wrinckle and flaw phenomenon can be avoided by using flexibleblank-holder,which is useful for forming large deformation parts.At the same time,aappropriate load force is the key factor when using flexible blank-holder. The thicknessof blank-holder and sheet influence the flexibility of the blank-holder.By makinganalysis of springback numerical simulation,we know that it can decrease the springbackby using flexible blankholder and the distribution of load force have little influence onspringback. However, when forming with non-uniform blank-holder force,the shaped partcan release the stress more thoroughly and leave a more uniform stress distribution.