外花键冷滚压成形过程单位平均压力

对外花键冷滚压精密成形的变形过程进行理论分析,用图解法建立了外花键冷滚压过程的塑性变形区滑移线场。在不同接触区域采用不同的摩擦条件,真实地反映了成形过程实际情况。根据滑移线场的应力场理论得到冷滚压成形过程中接触面上平均单位压力的封闭解。通过适当假设建立花键冷滚压有限元模型,应用有限元软件DEFORM对成形过程进行了数值模拟。将不同参数条件下平均单位压力的数值模拟结果与理论分析结果进行比较,两者吻合较好。     

渐开线花键冷滚压精密成形工艺分析及试验研究

花键冷滚压精密成形技术是一种高效、精密、少无切削的先进制造技术,具有成形效率高、节能、节材和零件成形性能好等特点.分析渐开线花键冷滚压精密成形工艺过程及原理,对成形过程的单位平均压力、接触面积、滚压坯料直径、滚压力及滚压力矩等进行求解.对渐开线花键进行冷滚压精密成形试验,分析零件变形区的金属流动规律,组织形成机理及塑性变形对成形性能的影响.试验结果表明,在花键冷滚压精密成形过程中,工件表层发生剧烈的塑性变形,晶粒沿齿廓呈连续的流线型分布,塑性变形区为细长的纤维组织,齿形截面硬度分布具有一定的规律性.试验所得零件无缺陷,硬度、耐磨性等较传统的切削加工花键大大提高,可满足使用要求.     

基于ANSYS/LS-DYNA的花键冷滚轧成形数值模拟

利用显式中心差分算法,借助有限元分析软件ANSYS／LS-DYNA,通过数值模拟,实现了花键冷滚轧成形过程的可视化。根据数值模拟的结果,讨论了齿形误差及其成因;揭示了滚轧过程中金属流动规律和应力变化情况;分析了冷滚轧前轴坯直径与成形后花键最大外径的关系,提出了轴坯直径的修改建议。研究结果为花键改进设计提供了定量依据,同时也为深入研究花键冷滚轧成形机理奠定了基础。     

板式翅片滚压成型的数值模拟

针对板式翅片加工现状,提出一种板式翅片滚压成型新方法。阐述了该方法的成形原理;在三维软件中建立了滚压刀具和工件的有限元分析模型,采用Deform-3D有限元分析软件对板式翅片滚压成型过程进行了数值仿真,获得了理想的翅片形状;分析了成形过程中工件的应力状态及滚压刀具的受力情况,为板式翅片滚压成型方法的研究和应用提供了重要理论依据。     

以DEFORM-3D实现花键轴精密冷滚轧成形模拟

使用有限元仿真软件DEFORM-3D,实现渐开线花键冷滚轧成形整个过程的数值模拟;针对金属大变形问题,DEFORM-3D提供了一个全自动的、优化的网格再划分功能,为充分利用此功能,采用间接方法实现渐开线花键冷滚轧成形过程的数值模拟,并对成形过程中工件与模具之间的相互关系、成形力和变形特点进行分析与研究,为模具及成形设备的设计提供了可靠依据.     

冷拉伸滚压塑性成形轧制力计算

应用ls-dyna对冷拉伸滚压成形过程进行数值模拟,得到冷拉伸滚压成形的变形力可分为径向进给力、切向滚压力和轴向拉伸力。研究表明,合理控制、匹配三者的大小有利于拉伸滚压成形,获得最佳的成形效果。分析、研究冷拉伸滚压成形的变形力能更好地掌握工件的变形情况,为合理设计工艺参数提供参考,为装备的动力选型提供依据。     

矩形花键冷挤成形的试验研究

本文对汽车后轿传动轴矩形花键采用冷挤成形工艺生产,进行了工艺分析。设计了矩形花键冷挤成形用齿形组合凹模。对花键采用冷挤工艺成形时的变形载荷、合理毛坯尺寸、花键齿形流动充填情况等,进行了试验研究。试验结果表明:用冷挤工艺生产的花键,表面粗糙度、尺寸精度均满足设计要求,是一种投资少、效率高的少无切削加工花键的先进工艺。本文以IVECO车和跃进车后桥传动轴的矩形花键冷挤成形为例,进行了冷挤组合凹模的设计,试验分析了花键冷挤成形工艺的变形特点。     

渐开线花键冷搓成形数值模拟关键技术研究

依据大变形弹塑性有限元理论和接触理论,借助于有限元软件ANSYS对渐开线花键冷搓成形的过程进行了数值模拟,对其中一些关键技术进行了研究,并通过模拟的顺利实现证实了其有效性。     

成形辊齿数对蜂窝半格结构件成形影响研究

高强度金属蜂窝芯的制备方法是将金属箔材滚压成为蜂窝半格结构件,然后将其胶结或点焊成为蜂窝芯。基于蜂窝半格结构件滚压成形的工艺特点,利用ANSYS/LS-DYNA有限元软件对蜂窝半格结构件滚压成形进行有限元建模及弹塑性分析,得到了箔材成形过程中成形辊齿数对成形件形状尺寸、应力应变的影响规律。将有限元弹塑性分析结果应用于成形辊设计及制造,并将成形件的仿真数值与实验数值进行比较。结果表明:运用有限元分析来解决传统箔材滚压成形的缺陷是有效的。     

外螺纹滚压过程有限元仿真模型研究综述

传统的外螺纹滚压过程参数优化大多采用试错法,依赖个人经验进行模具设计和工艺摸索,不仅费时费力,而且试验效率和经济价值极低。针对外螺纹滚压成形过程有限元模型进行研究已越来越受到人们的广泛关注,建立外螺纹滚压有限元模型,能够从应力-应变、滚丝轮最大成形力及最大成形扭矩等多角度深入理解外螺纹滚压成形过程中金属塑性流动规律。首次针对外螺纹滚压成形过程有限元仿真模型的研究进行综述,对外螺纹滚压模型进行分类,阐述了多个有限元仿真模型的特点及验证方法,并给出了相应研究结论及后续研究建议。     

基于ANSYS渐开线花键冷搓成形全过程的数值模拟

依据大变形弹塑性有限元理论和接触理论，综合考虑成形中的几何非线性、状态非线性、材料非线性以及工件与刀具的接触摩擦因素，借助有限元软件ANSYS对渐开线花键冷搓成形的过程进行数值模拟，方法新颖独特，其应用将对刀具的设计有参考作用。     

Metal flowing of involute spline cold roll-beating forming

The present research on involute spline cold roll-beating forming is mainly about the principles and motion relations of cold roll-beating,the theory of roller design,and the stress and strain field analysis of cold roll-beating,etc.However,the research on law of metal flow in the forming process of involute spline cold roll-beating is rare.According to the principle of involute spline cold roll-beating,the contact model between the rollers and the spline shaft blank in the process of cold roll-beating forming is established,and the theoretical analysis of metal flow in the cold roll-beating deforming region is proceeded.A finite element model of the spline cold roll-beating process is established,the formation mechanism of the involute spline tooth profile in cold roll-beating forming process is studied,and the node flow tracks of the deformation area are analyzed.The experimental research on the metal flow of cold roll-beating spline is conducted,and the metallographic structure variation,grain characteristics and metal flow line of the different tooth profile area are analyzed.The experimental results show that the particle flow directions of the deformable bodies in cold roll-beating deformation area are determined by the minimum moving resistance.There are five types of metal flow rules of the deforming region in the process of cold roll-beating forming.The characteristics of involute spline cold roll-beating forming are given,and the forming mechanism of involute spline cold roll-beating is revealed.This paper researches the law of metal flow in the forming process of involute spline cold roll-beating,which provides theoretical supports for solving the tooth profile forming quality problem.     

VISUAL SIMULATION OF COLD ROLL-FORMING BASED ON OBJECT ORIENTED PROGRAMMING

To simulate the process of cold roll-forming process, a new method is adopted. The theoretical foundation of this method is an elastic-plastic large deformation spline finite strip method based on object-oriented programming. Combined with the computer graphics technology, the visual simulation of cold roll-forming is completed and the system is established. By analyzing common channel steel, the process is shown and explained including theory method, model and result display. So the simulation system is already a kind of mature and effective tool to analyze the process of cold roll forming.     

矩形花键轴冷挤压的数值模拟分析

采用金属成形有限元分析软件DEFORM,模拟CG125摩托车发动机主轴的矩形花键冷挤压成形过程,得到挤压过程中的模具受力图及坯料的应力分布图.结合数值计算的结果,探讨冷挤压过程中的塌角与金属堆积现象.工艺实验表明,该冷挤压工艺与模具设计合理,数值模拟分析对冷挤压模具设计具有一定的指导意义.     

MECHANICS ANALYSIS ON PRECISE FORMING PROCESS OF EXTERNAL SPLINE COLD ROLLING

According to the suitable assumption, the deformation process of external spline cold rolling is analyzed. By the graphing method, the slip-line field of plastically deforming area in process of external spline cold rolling is set up. Different friction-conditions are used in different contact areas in order to realistically reflect the actual situation. The unit average pressure on contact surface of the rolling process is solved according to the stress filed theory of slip-line. And the formulae of the rolling-force and rolling-moment are established. The theoretical result is well consistent with the finite element analysis. A theoretical basis is provided for the precise forming process of spline cold rolling and the production of external splined shafts.     

矩形管冷弯成形的辊花设计及成形规律

依据矩形管冷弯成形的多道次孔型轧制特点,考虑轧前圆管坯与轧后矩形管存在的拓扑等价关系,建立了两者之间的形心映射数学模型,实现了矩形管冷弯成形过程的辊花设计,并进行了轧制实验。轧后产品满足GB/T 6728-2002的要求。基于弹塑性有限元法建立了矩形管冷弯成形的仿真模型,研究了冷弯成形的金属流动、纵向延伸和残余应力分布,确定了变形过程开裂危险区位置。     

花键冷滚压成形力测试与分析

根据花键冷滚压加工原理,按机床受力,将加工过程中的滚压力分为主轴转矩和径向进给力两部分。设计测试方案,用计算机数据采集系统测得了主轴转矩和径向进给力在滚压过程中的实时变化曲线,分析了它们的变化特征,得出压入阶段结束时滚压力取最大值。对不同的工艺参数进行实验,得到了工艺参数对最大滚压力的影响规律。     

准双曲面齿轮冷摆辗加工新方法及其数值模拟

针对目前准双曲面齿轮冷摆辗技术存在模具结构复杂、摆辗力相对较大等问题,提出了一种新型的冷摆辗方法。该方法简化了模具结构,采用局部线接触连续塑性成形。基于刚塑性有限元法基本理论,借助通用三维有限元软件DEFORM-3D对准双曲齿轮摆辗成形全过程进行了三维动态分析,研究了速度场量、接触区以及模具受力的分布和变化规律。研究结果揭示了准双曲面齿轮冷摆辗的变形规律。     

辊弯成型数值研究综述及全流程仿真关键问题

综述了辊弯成型数值研究的现状 ,总结了半解析法、有限条法、有限元法 3种研究方法的应用情况。指出动态显式有限元方法是建立辊弯成型全流程仿真系统的有效手段 ,并对其中的关键问题包括算法选择、引入各向异性和包辛格效应的材料本构模型、板带皱曲预示、接触回弹、轧辊强度校核等进行了探讨。     

Finite element simulation of plate or sheet metal forming processes using tetrahedral MINI-elements

In this paper, finite element prediction of sheet metal forming process is investigated using solid elements. A three-dimensional rigidviscoplastic finite element method with linear tetrahedral MINI-elements is employed. This technique has traditionally been used for bulk metal forming simulations. The solid element approach with remeshing capability is applied to simulating a plate metal forming process to reveal its possible problems. The similar approach is also applied to a typical sheet forming process. Both single- and double-layer finite element mesh systems are studied, with particular attention to their effect on the deformed shape of the workpiece and thickness variation of a cold sheet forming process. The procedure is applied to the well-known problem of the NUMISHEET93 international benchmark. The resulting predictions are compared with experimental observations found in the literature, and good agreement is noted.