Surface forming mechanism and numerical simulation study in four-roll flexible rolling forming.

This study investigates the surface forming mechanism in four-roll flexible rolling forming processes, addressing issues of low efficiency and significant residual stresses, particularly when dealing with lightweight high-strength materials such as LY12 aluminum alloy. Initially, the study systematically analyzes the variation in sheet curvature radius under different forming methods, considering the separate and combined actions of side rolls and flexible rolls in the pre-bending forming process. Subsequently, actual forming data is obtained by conducting four-roll flexible rolling forming on LY12 aluminum alloy experimental material. A numerical model is then established using finite element analysis to simulate key parameters such as stress, deformation, and temperature distribution during the forming process. Adjustments to process parameters are made based on the analysis of numerical simulation results to achieve optimized forming. Additionally, the uniformity of four-roll flexible rolling forming of LY12 aluminum alloy with different hardness and thickness is examined. The research findings reveal that optimizing process parameters leads to a 14.95 % improvement in forming accuracy and a 30.52 % reduction in residual stress for LY12 aluminum alloy sheets, significantly enhancing product quality and efficiency. This study not only deepens the understanding of the four-roll flexible rolling forming process but also provides a feasible optimization parameter scheme. The results offer specific guidance for the application of lightweight high-strength materials such as LY12 aluminum alloy in actual production, thereby providing important technical support for improving forming efficiency and quality.