椭圆件全缩口模缩口锥角的确定

以塑性理论为依据，讨论了一般缩口工艺难以解决的椭圆件全缩口问题，在保证周边不起皱的前提下，提出了椭圆件各次缩口凹模缩口锥角的确定方法。     

桶形件缩口成形工艺与模具设计

介绍了缩口工艺的概念、特点、主要工艺缺陷及影响缩口变形程度的因素。分析了桶形件的特点,通过比较传统缩口工艺模具设计特点,设计了桶形件缩口工艺的模具。在此基础上,对缩口模具的工作原理、模具主要零件相互关系及其作用做了详细的论述。实践表明,采用此工艺方案和模具结构,模具生产的零件符合精度要求,显著提高了桶形件生产效率和产品质量。     

7A04合金筒件缩口成形工艺研究

针对某7A04合金筒件的缩口结构,根据筒件缩口形状特点,结合7A04合金成形特性,设计了等温成形工艺方案和工艺工装,在此基础上进行了相应的工艺试验研究.结果表明,通过此工艺和模具,筒件缩口达到了要求尺寸,且缩口变形部位未出现裂纹、起皱等缺陷,成形效果好,从而为铝合金筒件缩口成形技术的应用提供了参考.     

双封闭球头筒缩口工艺与模具设计

介绍了缩口工艺的概念、特点、主要工艺缺陷及影响缩口变形程度的因素。分析了双封闭球头筒零件加工的工艺性，经过比较确定用缩口工艺来完成该件的加工制造。在此基础上，对所给零件的缩口工艺计算的内容和步骤做了详尽的介绍，给出缩口工序的次数、各次缩口工序的变形程度、毛坯的高度、工序件的尺寸并进行了压力机的选择。结合零件的试制。进行缩口模具的结构设计，并对模具的工作原理、模具主要零件相互关系及其作用做了详细的论述。通过对试件的质量分析，说明了缩口工艺计算和模具结构设计的结果能满足所给零件的加工工艺，试件基本达到了设计的要求。最后还指出了缩口工艺中常被忽略的变形对工艺过程的影响以及改进这一问题还需要进行的研究。     

风帽缩口加工工艺研究

通过风帽零件的加工工艺分析,确定采用缩口工艺加工该零件.介绍了风帽毛坯缩口模具结构及成形过程,进行了工艺设计,提出了缩口凹模的设计方法,保证了风帽缩口成形的顺利进行.     

壳体缩口工艺及模具设计

通过对壳体零件缩口工艺进行分析,介绍了零件的工艺参数的计算方法及缩口凹模的设计,同时介绍了模具结构及模具的工作过程,并对该零件缩口过程中出现的问题,给出了解决措施,保证了该零件缩口的顺利进行。     

厚壁筒形件弧形缩口工艺设计研究

邓厚壁筒形件弧形缩口工艺设计进行讨论，认为采取等体积原则设计变薄引伸弧形模对壁厚进行预成形，完全可以保证最终产品缩口后的尺寸要求，从而取消铰内孔切削加工，该工艺方法在几个产品多年生产实践中应用，取得了较好的经济效益。     

冷滚压钢管缩口工艺及工具设计

提出了一种简易的钢管缩口工艺实施方案,即利用闲置的旧车床,采用冷滚压法实现钢管的端部缩径;介绍了实现该工艺所需的缩口工具的设计与制造方法。实际应用表明,冷滚压钢管缩口工艺简易可行,缩口工具装卸方便,经缩口的钢管变形均匀。     

CPE机组缩口钳孔型设计

通过分析武钢集团汉口轧钢厂Ф114mmCPE机组径向滑块式缩口机的工艺特点,提出了缩口钳孔型的设计方法。经生产验证,该缩口机缩口效果较好,其顶管成材率和作业率均有较大提高。     

基于轴对称屈曲失稳的缩口力与临界缩口尺寸

采用主应力法和能量法对缩口成形工艺中的两个主要技术参数——缩口力和缩口尺寸进行分析，导出了以轴对称屈曲失稳作为破坏形式的临界缩口尺寸和缩口力的工程计算公式，所得结果对缩口工艺的拟定具有重要的参考价值。     

基于知识与CAX智能集成技术的收口工艺设计优化

收口工艺成形复杂,通常要对工艺设计进行CAE分析并根据分析结果对设计进行修改。采用基于知识与CAX(计算机辅助技术)智能集成技术,能较大的提高数值模拟的智能化水平,减少数值模拟软件对用户的要求。通过智能向导,模拟案例模板等技术将模拟参数选择、有限元模型确立等过程智能化,指导和帮助设计人员准确迅速地将收口工艺的设计从CAD开发环境转换到CAE分析环境中,并对有限元分析结果智能分析,利用节点回溯算法将CAE结果反映到CAD模型上,从而指导收口工艺的再设计过程。文章以自主开发的收口工艺设计优化系统为背景,通过实际案例,对基于知识与CAX智能集成的优化技术进行了阐述,实现了CAD/CAE的无缝集成,提高了收口工艺设计的质量和效率。     

Development of a methodology to form net-shape nosing shells by the backwards tracing scheme of the rigid-plastic FEM

A preform is designed by the backwards tracing scheme of the rigid-plastic finite element method (FEM) for net-shape shell nosing components without machining after formation. The current process of producing the shell nosing requires costly machining to produce the final product. Here the backwards tracing scheme of the rigid-plastic FEM, a novel method for preform design of metal forming processes, derives a sound preform for a net-shape shell nosing product. The current process is simulated by the rigid-plastic finite element analysis to check the metal flow involved in the forming with a trial preform and its modified preform. The two preforms are found to be inadequate for a net-shape shell nosing product. The first application of the backwards tracing scheme derives a preform producing a net-shape product numerically, but it is difficult to be formed economically. Thus an improved preform is designed by the backwards tracing scheme, which is suitable for net-shape manufacturing of the shell nosing components in view of production economy and the forming characteristics of the product.     

An analysis of the eccentric nosing process of metal tubes

In this paper, the finite-element method is used to investigate the cold eccentric nosing process of metal tubes with an eccentric conical die from circular tube billets. A series of simulations on the eccentric tube nosing using the program DEFORM-3D was carried out. The influences of the process parameters such as tube length, tube thickness, die fillet radius, die angle, friction factor, strength coefficient and strain-hardening exponent of the billet material on the critical nosing ratio of the tube are examined.     

热收口智能优化设计系统中的CAD/CAE集成技术研究

以自主开发的热收口工艺知识优化设计系统为背景,论述了基于知识对象模型的CAD/CAE集成技术,通过知识对象的桥梁作用,实现基于知识的CAE建模和基于知识的CAE智能反馈,应用CAE分析的结果指导改进工艺设计,实现CAD/CAM无缝集成。     

管件壁厚对收口影响的研究

建立了管件收口工艺的刚塑性有限元模型,运用DEFORM-2D软件对不同的管件壁厚进行收口成形的模拟研究,分析了不同的壁厚对收口质量、应力应变分布规律和行程载荷变化以及可能产生的缺陷等。结果表明：为了满足管件收口的尺寸要求,必须严格控制在该模具下的收口,应该保证管件的壁厚大于5mm而小于15mm。     

金属管接头复合成形过程有限元模拟及实验研究

针对凸筋类金属管接头提出了一种新的管接头复合成形工艺：“缩口－轴压－胀形”复合成形工艺,分析了该复合成形的工艺特点,利用刚塑性有限元方法对复合成形过程进行了模拟,得出了不同时刻的网格变形图和等效应变的等值线分布图,讨论了缩口半锥角和摩擦因子对成形极限的影响,将刚塑性有限元计算的结果与实验结果进行了比较,并得出了一些对生产实际有价值的结论     

钢管收口代替方钢热冲拔弹体毛坯加工工艺研究

重点介绍了炮弹新产品弹体毛坯由钢管收口代替传统的方钢热冲拔加工工艺,弹体一次收口工艺研究过程。确定的弹体生产工艺,工艺过程简单,产品质量得到大幅度提高,改善了工作环境,降低了劳动强度,在同行业处于领先水平,并为新型薄壁弹种的研发奠定了工艺基础。     

Analyzing the cold-nosing process using elasto-plastic and rigid-plastic methods

This paper used the rigid-plastic and elasto-plastic finite-element method in conjuction with eight-node and nine-node quadrilateral elements to develop a computer program to simulate cold-nosing processes.

In the course of the study, simulation was carried out not only on cold nosing a curve die, with the results compared with available experimental data from Battelle Columbus Laboratories to verify the accuracy of the FEM program, but also on cold nosing using a straight die, analysed by means of the rigid-plastic FEM program to enlarge application of the latter.

The results of the cold-nosing simulation were obtained in terms of load-displacement curves, thickness distributions, elongations, strain distributions and die-pressure distributions. According to these findings, the final shape and possible defects of the product can be predicted, thus facilitating better understanding of this type of metal-forming process.     

收口筒节锻造工艺研究

针对收口筒节在生产过程中经常出现尺寸超差、椭圆、长短面不齐、薄厚不均等质量问题,通过研究工艺编制及生产实践来提高锻件质量。     

Modified looping technique for remeshing of forming simulations with free surface folding

In finite element simulations of forming processes with a complex geometry, free surface folding phenomenon is likely during simulations when die design or the size of initial billet is inappropriately determined. In such cases, free surface geometry becomes so acute that mesh generation may be impossible with a conventional looping technique automatically. In order to solve this kind of problem, looping technique was modified to generate boundary elements for the acute geometry with a better mesh quality. The developed technique was implemented to the in-house bulk metal forming simulation program CAMPform and applied for forming simulations of ring gear forging and nosing in which surface folding defects occur. It was found that folding phenomenon was successfully handled with the currently developed algorithm and suitable process conditions to eliminate the free surface folding were determined through numerical simulations.