Experimental Study On How The Structural Parameters Of Drawbead Impacting On The Subsequent Forming Properties Of High Strength Steel Plates

Growing environmental problems lead to lightweight car body becoming the development trend of auto industry. At present, the main method of reducing weight is using high strength steel instead of common steel plate. Decrease the thickness of the plate on the premise of meeting the stiffness of car body to achieve weight loss. Because the car body stamping parts are in complicated shape,so the drawbeads should be installed to control flowing sheet. The formability of high strength steel sheet is poorer than common plate. When high strength steel sheet goes through the drawbead, Complex bending and reverse bending process will happen. The formability of high strength steel sheet changes greatly, and high strength steel sheet is easier to rupture. so, the subsequent forming performance of high strength steel plate must be considered when drawbeads are designed.Designs a drawbead test system independently for study of the subsequent forming performance of high strength steel sheet. The test system is fully functional, and the structure is reasonable, which provides reliable guarantee for the experiment.Designs orthogonal experiment to study that how the structural parameters of semicircular drawbead impact on the subsequent forming performance of three kinds of commonly using automobile high strength steel plate. The results show that the radius R is the most significant parameter to influence the subsequent forming performance. The influence degree of other parameters changing with plate yield strength presents different significance but show the phenomenon that with yield strength increasing the influence degree improves. Use experimental regression analysis method to deduce the regression equation for structure parameters of semicircular drawbead and the subsequent forming performance parameters of high strength steel plate DP590. Combine orthogonal experiment with regression equation to deduce design principles of semicircular drawbead for high strength steel plate DP590Design regression orthogonal test to study that how the trapezoidal drawbead affects the subsequent forming performance of high strength steel plate DP590. The results show that notch radius r1 and r2 are the most significant structure parameters that influence the subsequent forming performance. Deduce the regression equation for structure parameters of trapezoidal drawbead and the subsequent forming performance parameters of high strength steel plate DP590. The design principles of trapezoidal drawbead are concluded according to the results of the regression orthogonal test analysis for high strength steel plate DP590.