Experimental and numerical investigation of skidline in sheetmetal forming processes

With the increase in competition in the automotive industry, aggressive looking vehicles based on brands gaining superiority over each other are increasing. When vehicles have aggressive style lines, they also bring feasibility problems with them. In this study, experimental and numerical studies were conducted to determine the skidline behavior, which is one of the deformations that occur during forming in the visible sheet metal parts of vehicles. In this direction, 0.73 mm thick CR4 material, which is frequently used in panel parts, 1000 mm x 80 mm sample type was selected. In order to determine the problem, a hydraulic test device was used with the help of 3 pistons in the experimental studies. The upper buffer force was determined as variable (40 kN, 50 kN, 60 kN) to compress the sample. While the upper buffer was holding the sheet metal part, both the pulling steels moved the sheet metal 110 mm in one direction at a speed of 100 mm/s at the same time, and the R8 punch forced the sheet metal to be shaped with a 50 mm stroke and a speed of 100 mm/s. As a result of this study, the deformations formed under and above the sheet were measured. In the finite element analysis program, the Hill48 plasticity model was used with the same speed and force parameters. As a result of this study, the problem was determined with the skidlines, unbending strain and contact pressure outputs in the finite element analysis program. The results of the experimental and numerical methods were compared. As a result of the comparisons, the differences in the experimental results of the skidlines, unbending strain and contact pressure outputs in the finite element software were determined.