【作者】 王映品；

【导师】 夏琴香；

【作者基本信息】 华南理工大学 ， 机械制造及其自动化， 2011， 硕士

【摘要】 本课题来源于国家自然科学基金项目(50775076)“非圆截面空心零件旋压成形方法及变形机理研究”。为了推广非圆旋压的应用领域及加深理论研究,本论文主要以五边形横截面空心零件为研究对象,对其旋压成形过程进行数值模拟及试验研究,主要工作如下:1、运用ADAMS求出五边形截面空心零件旋压成形的旋轮轨迹,并分析相应的参数设置。运用MSC.MARC建立五边形截面空心零件旋压成形的有限元数值模型,对有限元建模网格的划分、时间步长的设定及常见错误类型等进行了探讨。2、对比分析不同形状的五边形零件与不同边数的圆弧形零件旋压成形后的应力应变分布情况,研究非圆截面空心零件旋压成形的特点。基于正交试验分析了主要工艺参数对工件最大减薄率及最大旋压力的影响规律;并通过单因素的数值模拟研究了主要工艺参数对五直边圆弧形零件的壁厚分布及回弹角的影响规律。3、通过分析旋压过程旋轮与芯模的接触情况及偏差,对比非对称解析法与离散数据点的B样条曲线拟合法所设计靠模型面的误差。由于这两种方法的误差较大,结合误差的特点研制出“虚设滚子法”,经验证该方法较为灵活,且误差较小。4、通过对比零件的外形尺寸、壁厚分布及旋压力的结果,验证了所建模拟与试验相符合。采用正交试验验证了影响壁厚最大减薄率的主次因素为:相对高度>旋轮圆角半径>进给比。对三向旋压力进行测量,并分析了主要工艺参数对轴向旋压力的影响。综上所述,本文利用数值模拟与工艺试验相结合的方法,探索出了五直边圆弧形截面空心零件旋压的成形机理,达到了理论指导实践、预防产品缺陷的目的。为后续多种非圆横截面空心零件旋压成形方法以及旋压成形机理的探索奠定基础,其研究具有较高的理论意义和实践应用价值。更多还原

【Abstract】 This paper is financially supported by the National Natural Science Foundation of China“Research on spinning forming method and deformation mechanism of the hollow part with non-circular section”(No. 50775076). In order to spread the application of non-circular cross-section part spinning and enhance the theory research., the numerical simulations and experiments for the pentagonal cross-section hollow-parts were mainly studied, the following works were carried out:Firstly, the pentagonal cross-section hollow-parts spinning FEM models with MSC.MARC was built, and the meshing, step time setting and some Exit numbers in building the models was analyzed. ADAMS was ddopted to solve the roller’s track of pentagonal cross-section hollow-parts spinning, and the setting of relevant parameters were discussed. Secondly, compared the stress-strain distribution of different kinds of pentagonal cross-section hollow-parts spinning, and different arc cross-section parts, try to research the mechanism of non-circular cross-section parts spinning. Based on orthogonal test method to analyze the influence laws of main parameter effected the maximum thickness reduction and maximum spinning force; from single factor to analyze the parameter affected of wall thickness distribution and rebound angle.Thirdly, analyzed the roller and mandrel’s contact situation and deviation, compared the errors of profiling mandrel designed by the asymmetry analysis method and the method of B-spine curves fitting of the scatter data. The error both are too large, then develop the“nominal roller method”, after validate the method is agility and tiny error.Fourthly, compared the outline, thickness distribution and spinning force to validate simulation is consistent with experiment. Based on orthogonal test, the influence sequence on the maximum thickness reduction being the relative height of workpiece, feed rate and roundness radius of roller was validated. Measured the three directions spinning force Fn, Fz and Fy, and then analyzed the parameters influence law of axial spinning force Fz.To sum up, this paper through the numerical simulation and the technology testing, obtained the spinning forming theory of the pentagonal cross-section hollow-part, and the project of spinning faults prevention is realized. The research provides theoretic foundation for the spinning forming method and forming mechanism of the other kinds of non-circular cross-section hollow parts. This paper is valuable on both theory and practical application.更多还原