Research On Methods Of Inverse Calculation And Optimization For The Weld Line Position Of Laser Tailor-welded Blanks

Due to the characteristics of Tailor Welded Blank, the weld line drifts inevitably in the process of forming, which will cause the deviation of the design and the actual location of weld line. The deviation will affect the formability of Tailor Welded Blank, distribution of material, wear performance of mold surface and even cause the thin side material shrinkage defects such as wrinkling and so on. At the present stage,the Tailor Welded Blank weld line deviation mainly depends on the control of process and process parameters adjustment measures, but the effect is limited and sometimes the process and process parameters will affect the sheet metal forming quality.Aiming at thees above mentioned problems of the deviation of the design and the actual location of weld line and the forming quality, which caused by weld line drift in the process of forming. This thesis makes in-depth analysis in order to improve weld line position precision and the Tailor Welded Blank formability, and the main work was carried out as follows:Based on the grid mapping, the weld line position for sheet metal is inversely optimized, the initial position of weld line is appropriately decorated and the weld line position precision as well as Tailor Welded Blank formability are properly controlled by adjusting process parameters, after which a car door panel model simulation and physical experiment are verified. The results show that through this direct reverse weld line location of Tailor Welded Blank method, which can obviously improve weld line position accuracy and overall sheet formability, the high accuracy of car door panel model simulation and physical experiment verifies the validity of the proposed method in this thesis.Based on grid mapping, uniform Latin Square and genetic algorithm, this thesis proposed a method to optimize the weld line position. The grid mapping firstly ensure the original limit position of weld line and the uniform Latin Square then ensure the end point position of the weld line. The objective of genetic algorithm is to minimize the weld line position deviation, which is subject to the sheet’s no-wrinkling and no-cracking.Combining with the car door panel model simulation and physical experiment, the results show that the optimized weld panel performs better in the stamping process,meanwhile the weld line position accuracy and the forming quality are greatly improved. This method can inversely obtain the weld line to controlaccuracy of the weld line position and can also directly prove the feasibility of inverse method.