| Sheet metal forming is a very important plastic working technology which has been widely used in such industrial domains as motorcar, aviation and spaceflight, etc.. Automotive industry plays an important role in China, and it's an important marker to measure the industrial level of a country. In recent years, there are three major issues of energy, pollution and safety in the all world's automotive industry. So it's an inevitable trend to use High-Strength Steel(HSS) instead of common plate. HSS can reduce vehicle weight and increase security, but because of its own material properties, there is the biggest problem of poor formability and more springback. At present, most domestic and foreign scholars mainly control the forming quality of HSS by means of variable holder force technology,thermal and hydraulic forming technology. So this paper puts forward a new forming technological method——the controllable drawbead(CD) technology in order to improve the formability of HSS. Now there is not yet relevant research in China, and only Michigan Technological University has been preliminary studying the CD technology.Firstly, the CD technology was put forward by the laws of box drawing forming with semicircle straight fix and discontinuous drawbead in order to improve the formability of HSS. The finite element model of CD-JAC590Y HSS box deep drawing was established by numerical simulation Dynaform. Six different cross section and end shape CDs and three different CD movement paths were designed. The test scheme was determined by orthogonal test design. By means of the evaluation criteria of HSS forming limit diagram and optimization theory, different CDs and their moving paths influenced by box forming formability were discussed. The following conclusions are obtained:The limit drawing depths,the optimal moving path(ascent——halt——descent) and the optimal combinations in different CD moving paths are obtained. Besides, the maximum limit drawing depths of six different CDs in different test groups respectively increase 25%,10.34%,31.51%,12.85%,20.80%,10.01% compared to those of 5mm fix drawbead. Main influence factor H1 and H2 of the optimization moving path by range analysis are found. Meanwhile, the increasing rate of punch drawing force and CD resistance with deep drawing is from lager to small, finally begins to decline. The results show that the different CD moving paths have little effect on the strain paths of box sidewall and die corner, which have significant effect on punch corner. Eventually, the response surfaces composed of the CD main influence factor H1,H2 and limit drawing depth are established by the combination of GA-BP neural network and Latin Hypercube.Secondly, in order to verify the correctness of simulation result, it is necessary to design the experimental device to check and analyze the simulation result. The CD-HSS box drawing experimental device included four parts of die structure,lever mechanism,hydraulic and electric control system were designed based on the CD movement principle.Finally, the CD forming laws were applied to the deep drawing simulation of HSS automobile panel based on CD technology. The automobile engine tunnel-side panel was selected as an example. At the same time, the model of CD-JAC590Y HSS deep drawing was established. The results show that part smallest thickness significantly influenced by CD is determined. Then two different test groups are selected to research the whole part thickness distribution law. It is verified of part smallest thickness significantly influenced by CD. The main influence factor H2 and CD optimization moving path combination by range analysis of part average smallest thickness are found. Meanwhile, the model of GA-BP neural network is established to research part forming influence law of the factor H2. In the end the influence law curve and regression equation are obtained.
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