圆锥形件拉深成形侧壁起皱预测

发布时间：2019-04-12 13:02

【摘要】：圆锥形件是最典型的曲面拉深类零件。其拉深成形过程中,侧壁材料处于悬空状态,易发生起皱。侧壁起皱的存在严重影响着成形零件的使用和外观、甚至可能损坏模具。因此,研究侧壁起皱的成形机理,分析材料参数和工艺参数对侧壁起皱的影响规律,对预防起皱的发生有很重要的意义。首先分析了圆锥形零件成形的特点,将成形毛坯在变形过程中分为五个区域:锥形底部区、凸模圆角区、模具间隙的悬空侧壁区、凹模圆角区、法兰区。运用主应力法,推导了悬空侧壁部分和法兰的应力公式,讨论了悬空侧壁部分和法兰的应力分布规律。给出了侧壁起皱可能发生的位置在侧壁靠近凹模圆角半径处。基于ABAQUS/Explicit模块对圆锥形件拉深成形过程进行了数值模拟。给出单元选择、材料模形、网格的划分、接触与摩擦的处理、载荷的施加与边界条件等关键技术的处理方法。数值模拟的应力结果与理论分析相符合,证明了数值模拟的方法是正确的。运用能量法和增量理论建立了圆锥形侧壁起皱的理论,得到了悬空侧壁起皱的临界表达式。并提出了满足求解边界条件的新挠度函数。通过Matlab编写程序和ABAQUS有限元模拟相结合,实现了侧壁起皱的预测。预测了挠度函数、屈服准则、毛坯材料参数(弹性模量、泊松比、硬化系数、应变强度系数、厚向异性系数以及板料厚度等)及拉深成形工艺参数(压边力、凹模圆角半径、模具间隙、摩擦因数等)等因素对圆锥件侧壁起皱的影响规律。本文研究为圆锥形件在拉深过程中预防侧壁起皱的发生提供了良好的参考价值。
[Abstract]:Conical part is the most typical surface drawing part. In the deep drawing process, the side wall material is in the state of suspension, which is prone to wrinkle. Side wall wrinkling seriously affects the use and appearance of forming parts, and may even damage the mold. Therefore, it is of great significance to study the forming mechanism of side wall wrinkling and analyze the influence of material parameters and process parameters on side wall wrinkle, which is of great significance to the prevention of side wall wrinkling. Firstly, the forming characteristics of conical parts are analyzed. During the deformation process, the forming blank is divided into five regions: conical bottom area, punch fillet area, hanging side wall area of die clearance, concave die fillet area and flange area. By using the principal stress method, the stress formulas of the suspended side wall and flange are derived, and the stress distribution law of the suspended side wall and flange is discussed. The possible location of side wall wrinkling is given near the radius of the die fillet. Based on the ABAQUS/Explicit module, the deep drawing process of conical parts is numerically simulated. Some key techniques, such as element selection, material shape, mesh division, contact and friction treatment, load application and boundary conditions, are presented. The results of numerical simulation are in good agreement with the theoretical analysis, and the method of numerical simulation is proved to be correct. The theory of cone side wall wrinkling is established by means of energy method and increment theory, and the critical expression of hanging side wall wrinkle is obtained. A new deflection function satisfying the boundary conditions is proposed. Through the combination of Matlab program and ABAQUS finite element simulation, the side wall wrinkle prediction is realized. The deflection function, yield criterion, blank material parameters (elastic modulus, Poisson ratio, hardening coefficient, strain intensity coefficient, thickness anisotropy coefficient and sheet thickness, etc.) and drawing process parameters (blank holder force, die fillet radius, etc.) are predicted. Effects of die clearance, friction factor and other factors on side wall wrinkle of conical parts. This study provides a good reference value for the prevention of side wall wrinkle in the drawing process of cone-shaped parts.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG386.32

【共引文献】