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研究目的:验证无芯模旋压工艺可行性,同时深入探究此新型工艺机理,研究并获取旋轮轨迹曲线参数化控制及其对于零件成形精度的影响趋势。创新要点:基于贝塞尔曲线实现对于无芯模旋压旋轮轨迹曲线的参数化控制;通过构建包括成形与回弹工艺过程的无芯模旋压仿真模型,研究参数化轨迹曲线对成形件壁厚及形状精度的影响趋势及关系,同时对成形过程变形区应力应变进行了深入探究分析。研究方法:1.基于三次贝塞尔曲线实现对于旋轮轨迹曲线的拟合以及参数化控制(图3);2.利用LS-DYNA软件实现对无芯模旋压成形及回弹工艺综合仿真及其过程、结果数据的提取;3.研究不同参数化轨迹曲线下成形件壁厚及形状精度变化趋势(图12和13),获取量化轨迹曲线对于零件成形精度影响关系(表3),并通过增加实验组验证所获关系模型;4.提取成形过程中及成形后板料变形区应力及应变数据(图14–19),深入探究上述变形机理。重要结论:凹轨迹曲线下,坯料中部出现最大减薄及变形程度,且降低曲线曲率,形状精度提高;凸轨迹曲线下,最大减薄及变形区域出现在坯料后部,且降低曲线曲率,壁厚及形状精度均提高。
The purpose of this study is to verify the feasibility of a non-core mold spinning process. At the same time, the new process mechanism is explored deeply and the parametric control of the rotary track curve and its influence on the forming accuracy of the part are also studied. Innovative points: based on the Bezier curve for non-core mold spinning wheel curve of the parametric control; by including the forming and rebound process of non-core mold spinning simulation model to study the parametric trajectory of the forming parts Wall thickness and shape accuracy of the trend and the relationship between the deformation of the deformation zone during the stress-strain in-depth exploration and analysis. Research methods: 1. Based on the cubic Bezier curve to achieve the curve of the roller curve fitting and parametric control (Figure 3); 2. Using LS-DYNA software for coreless mold spinning and rebound process simulation And the extraction of the process and result data. (3) To study the variation trend of wall thickness and shape accuracy under different parameters (Fig. 12 and Fig. 13), to obtain the relationship between the quantitative trajectory curve and the part forming accuracy By adding experimental group to verify the relationship between the model obtained; 4. Extraction of forming and forming sheet deformation zone stress and strain data (Figure 14-19), in-depth study of the above deformation mechanism. The main conclusions are as follows: Under the concave trajectory curve, the maximum reduction and deformation of the blank appear in the middle of the blank, and the curve curvature decreases and the shape precision increases. In the convex trajectory curve, the maximum thinning and deformation area appear in the back of the blank, Thickness and shape accuracy are improved.