An effective method for predicting the shape of doubly curved sheet metal in continuous roll forming
An effective method for predicting the shape of doubly curved sheet metal in continuous roll forming
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DOI：
10.1007/s00170-023-10825-3
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
Jia-xin Gao;Z. Cai;Xi Zhang;Ming-wei Wang;Weiguang Zhang;Qing-min Chen
中科院分区：
文献类型：
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作者：
Jia-xin Gao;Z. Cai;Xi Zhang;Ming-wei Wang;Weiguang Zhang;Qing-min Chen
连续辊轧成形（CRF）是一种创新的、功能强大的工艺，仅使用一对可弯曲辊就可制造三维（3D）表面。通过调整轧辊的弯曲形状和辊缝的大小，可以形成不同类型和形状的双曲面零件。本文提出了一种在CRF中预测双曲面板料形状的有效方法，即分别处理由塑性和弹性变形引起的板料曲率，并将两者的影响叠加，从而求解实际的横向和纵向曲率。在推导基本方程时忽略了重力的影响，并通过有限差分法验证了基本方程的合理性。为了验证曲率计算公式的适用性，对两种典型的双曲面进行了有限元模拟和成形实验。模拟结果与实验数据非常接近，证明了有限元模拟的准确性。在不同的最大压缩比、坯料宽度和辊缝中心线半径条件下，理论计算得到的成形曲面与有限元模拟得到的成形曲面吻合较好，证明了推导公式的正确性。将该方法推广到基于刚性变截面轧辊的三维曲面轧制过程，发现该方法同样适用于中心压下量较小的情况。
Continuous roll forming (CRF) is an innovative and powerful process for manufacturing three-dimensional (3D) surfaces using only one pair of bendable rolls. By adjusting the bending shapes of the rolls and the size of the roll gap, doubly curved parts with different types and shapes can be formed. This paper presents an effective method for predicting the shape of doubly curved sheet metal in CRF, that is, the sheet curvatures caused by plastic and elastic deformation are tackled separately, and the effects of the two are superimposed, so as to solve the actual transverse and longitudinal curvatures. The influence of gravity is ignored in the derivation of the basic equation, whose rationality is verified by the finite difference method (FDM). In order to confirm the applicability of the curvature calculation formulas, finite element simulations and forming experiments for two typical doubly curved surfaces are carried out. The simulated results are extremely close to the experimental data, demonstrating the accuracy of the finite element simulation. Under the conditions of different maximum compression ratios, blank widths and radii of the roll gap centerline, the forming surfaces gained by theoretical calculation fit well with those obtained by finite element simulation, thus proving the validity of the derived formulas. The method presented in this study is extended to the process of 3D surface rolling based on rigid variable-section rolls (TSRRAR), and it is found that the method is also applicable in the case of small central reduction.