【作者】 林乔荣；

【导师】 周杰；

【作者基本信息】 重庆大学 ， 材料加工工程， 2003， 硕士

【摘要】 异形管件液压胀形是利用液体介质在管坯内部施加高压，从而使管材沿径向局部扩张变形的一种金属塑性成形工艺，它属于管材深加工技术范畴。该技术始于二十世纪60年代，近10年来由于汽车工业发展的需要，国外对这种技术日益重视。该技术不仅简化了模具结构，而且可以制造出采用其它成形方法所不能制造的复杂曲面工件，它对提高汽车零部件的稳定性、零部件综合机械性能、减少零件加工数量、减少工序、节省材料、降低成本和减少汽车自重有十分重要的意义。而且由于异形管件液压胀形时良好的应力状态，它可以比其它成形方法获得更大的变形程度。它可以与弯曲、压印、冲孔等工序复合，取得更大的经济效益。异形管件液压胀形可以在普通液压机或专用液压胀形压力机上配以专用模具装置完成。所谓异形管件，是指相对于直管而言形状不规则的管形零件，实际应用中通常有T型管、多通管、异径管、凸筋管、波纹管等。本课题主要研究异径管，这些异形管产品在工业中广泛应用，需求量大。在消化吸收国内外文献资料的基础上，利用动力显式有限元模拟软件DYNAFORM在国内首次模拟出胀形比达1.8的胀形结果。分析了异形管液压成形过程和成形规律，研究了胀形介质的选择、原始管坯尺寸的确定、管材的成形性能、液压成形工艺的实施方法等关键技术问题。运用有限变形理论，以运动方程和边界条件为基础，推导出模拟异形管液压胀形的动力分析有限元计算列式，给出了基于时间中心差分的位移场的显式求解法，并对数值积分法、应力应变的计算、边界条件的处理等关键问题进行了深入研究。采用动力显式有限元模拟软件DYNAFORM模拟了加载路径对成形过程影响规律、最小圆角半径与成形内压关系、不同材质对成形影响规律、摩擦系数与管壁厚度分布关系、通过分析异形管件成形过程缺陷得出胀形工作图。同时，提出了异形管件截面设计原则，模具设计原则以及管件材质特性确定方法。本文的分析方法和结论对于空心零件的成形将具有较为普遍的指导和参考意义。更多还原

【Abstract】 The hydroforming of Abnormity Tube using liquid to apply high internal pressure to the tube so as to make the tube deformed along radial is a new forming process of plastic forming, which belong to the tube deep process technique.category. it iniatiated in the years of 60th of 20th century and with the increasing demands of auto industry in the past 10 years, many foreign countries have paid more and more attention to the technique. It not only simplified the tooling structure, but also can manufacture many parts with complex surface such can not be manufactured by other forming process. It has the significant meanings in improving the stability and the integrative mechanical performance of the auto components, reducing the amount of process and working procedure, saving material, reducing costs and lessening the deadweight of the automobile. Further more because of the well stress state when hydroforming, it can achieve greater deformation than other forming process. It can compound with other working procedure such as bending, marking, and punching so as to achieve greater economy benefit. The hydroforming of Abnormity Tube can carry through in common hydraulic press or special hydroforming press.The so-called Abnormity Tube is the anomalistic shape tube relativing to the straight tube and in the practical application the T-shape tube, multibarrel tube, different diameter tube, protruding rib tube and corrugation tube are the familiar shape. This paper deals with the different diameter tube, all the Abnormity Tube are widely applied in the industry.On the base of absorbing domestic and overseas literature information, the result of expanding rate reaching 1.8 has been first time simulated in domestic. The hydroforming process and the forming rule has been analysed, the choice of the expanding medium, the confirmation of the origin tube size, the material forming capability, the implement method of tube hydroforming of has been investigated. By using finite deform theory, movement equation and boundary condition, the finite element calculate formulas for Abnormity Tube Hydroforming has been induced and the explict solution method of the displacement field based on the time middle difference has been given. In addition, some other key issues such as numerical integral method, stress-strain calculation and the disposal of boundary condition have also been lucubrated. By using the dynamic explict finite element simulation software -<WP=6>DYNAFORM, the results that the effect of the loading path on the forming process and the relationship between the friction coefficient and the distributing of the thickness of the tube have been achieved. And also achieved the expanding working chart by analyzing the forming failures. Meanwhile, the design principle of the cross section of the abnormity tube, the principle of mould design and the confirmation method of the tube material characteristic have been brought forward too.The analysis method and the conclusion of this paper has relatively universal guidance and reference meanings to the forming of hollow parts.更多还原