Differential Slab Roll Forming Simulation Study

Roll forming is a kind energy saving and efficient sheet metal forming process. Quality of products could be improved and the product development of the cycle time could be shorten by Roll forming.Production efficiency could be improved.Laser welding blank metal, with different thickness and different materials, can be welded together by Laser. The performance of parts of the body would be improved by Laser welding technology, reducing the vehicle mass and improving the reliability of the vehicle structure and safety. Tailored welded blanks would have broad prospects in the automotive field because of these excellent performances. The feasibility of roll forming was discussed. Many technical problems of Tailor welded blanks in the roll forming need to be solved. Some preliminary study of tailor welded blanks in roll forming would be put into practice.In this paper, FEA software MSC.MARC was used to simulate roll forming process of tailor welded blanks with different thickness. Roll forming process of different thickness and strength ratio tailor welded blanks were simulated. The cause of the residual equivalent stress uneven distribution on thin and thick sides was analyzed. And the rolling force during the process was analyzed, and the springback after forming are compared in order to find the law of blanks with the appropriate strength ratio and thickness ratio. The results show that:(1) Both sides of the forming force are asymmetric because of different thickness and material strength. Peak residual stress is in the bending corner.Large residual stress concentration is distributed on area where is nearby bending corner on; there will be relatively large and uneven distribution equivalent residual stress on flange legs border.A little residual stress is distributed in the web. (2) During forming process, each bending angle increment is proportional to the total force (3) Thickness ratio and strength ratio would have a great effect on both sides Springback.Some theoretical guidance for actual difference thickness of tailor welded blanks roll forming process design has been given in this paper. It is great significance for designing a reasonable thickness and strength ratio to get a better shape results and to avoid product defects, reducing production costs.