Study On Nonlinear Weld Lines Arrangement For HSS Laser Welded Blanks With Different Thickness

Recently, the development of light car body has become main trend in the auto industry for the safety, economical and environmental consideration. The high strength steel laser tailor welded blanks have been applied, because those take the both advantages of these two technologies. Due to the flexible design weld on the part of panel with complex geometry and size, the tailor welded blank with nonlinear welds will be the future development aim of TWBs. But the phenomenon that the weld location has a strong influence on the formability in TWBs forming has been found. So, it is necessary to study the relationship between nonlinear weld location and forming formability in order to guide the arrangement of welds on the TWBs.The followings are the main content done in this paper:1) The deformation theories on uniaxial tensile with different kind of weld location and their results are presented. The finite element simulation process concerning sheet metal forming and simulation model set-up about tailor welded blanks forming are discussed. The simulation process for HSS laser tailor welded blanks with nonlinear welds forming is obtained at last.2) By locating the different nonlinear welds which have the relationship with main stretch direction and draw-in direction individually to form the U part, the law of the relationship between welds location and formability is studied. And the guidelines for welds arrangement are presented by the law.3) By locating 5 different nonlinear welds to form the part of rectangular box, the law of the relationship between welds location and formability is studied under the complex deforming condition. The law obtained in the U part forming is proved. The forming characteristics of the rectangular box have certain influence on the formability.4) On the base of above research, the tailor weld blanks with nonlinear welds are used to form the rectangular box in the experiment. The results of experiment and numerical simulation are compared. The numerical simulation process is validated and the law obtained form previous study is proved by the analysis.