The Numerical Simulation Analysis Of The Rectangular Box Straight Springback Law

Springback is one of the main factors which affect the quality of sheet metal deepdrawing, also it is one of the most common defects during the process of sheet metal forming.Rupture and springback are the two main flaws during the sheet metal forming, andspringback is the most difficult one to be controlled. The form of springback can have animpact on the surface quality and accuracy of shape and size of the stamping parts directly.Since springback is a real problem in industrial production and can not be avoided, to explorethe regularity of parts springback and the control method to reduce springback becomes animportant part in the process of sheet metal forming. Mean while, it is one of the hot issueswhich was concerned about the academic for a long term.By referring to large numbers of relevant literatures, the article expounds the researchbackground of the study, and by the study on the forming mechanism of box-shaped pieces,we analyzed the impact factors affecting the amount of springback, and discoursed thecalculation method of springback. We took a simulation of the rectangular box model withdifferent aspect ratio, radius of die, die corner radius and draw depth using ETA/DYNAFORM finite element software, and get the associated springback law. Finally,introduced some method to control the springback, and controlled the springback ofrectangular box using optimized process parameters and mold surface compensation method.The studies of the paper showed that: The rounded area of the rectangular box partsspringback outward after unloading.The straight edge part depressed inward when the sizewas small, and bulged outward in a larger size.Whether the straight edge rebounded inward oroutward only associated with the length of straight edge and have nothing to do with theaspect ratio of the part.When the draw depth is small, the middle region of straight edgebulged outward and part of the area between the two regions will recess inward; when thedraw depth is large, the middle region of straight edge recessed inward.When the die radius islarge, the middle region of the straight edge bulged outward, the part near the fillet area recessed inward; when the die radius is small, the middle region of straight edge recessedinward. When the die radius is large, the middle region of the straight edge rebounded inward;when the draw depth is small, the middle region of the straight edge bulged outward, and partof the area between the two regions will rebound inward.In the paper, we studied on the straight edge springback law of long rectangular boxparts and combined with the mold surface compensation method control the straight-edgespringback. These studies have an important guiding significance on the stamping process anddie design of rectangular box parts.