汽车覆盖件设计全流程CAD/CAE系统开发与应用

为解决目前CAD/CAE系统中数据转换精度损失和设计变更引起分析模型重复建模的问题,基于UGSNX平台开发了面向汽车覆盖件设计全流程的CAD/CAE集成系统FASTAMP-NX,该系统完全集成于NX环境,并基于特征造型技术建立了设计和分析相统一的关联参数化模型,避免了数据转换引起的精度损失和重复建模问题.系统求解器基于有限元逆算法和改进的动力显式算法,可应用于产品设计、工艺设计和虚拟试模的全流程,真正实现了"设计-分析-修改-优化"的闭式循环,极大地提高了汽车覆盖件产品和模具设计与分析的效率.     

汽车覆盖件成形工艺参数多方案管理系统

基于Siemens NX平台开发了汽车覆盖件冲压成形同步模拟系统Forming Analysis Wizard（FAW）,采用UDO关联技术与参数化关联技术,实现了工艺参数多方案管理功能。该系统可以在同一工序中定义多种方案,并对不同方案的工艺参数进行有效管理,为工艺优化提供参考依据。以某后排座靠背支架模型为实例,设置多...     

基于SolidWorks的包装容器结构参数化设计实现

探讨了通过Visual Basic6.0(VB)用户界面对SolidWorks进行尺寸驱动,以实现中空塑料瓶的结构三维参数化设计的思路,利用SolidWorks提供的应用程序接口(API),通过直接输入相关设计参数,自动实现产品的三维建模。对包装容器结构的结构设计有一定的借鉴作用。     

装配体的参数化设计研究

通过参数化零件的数据关联分析,并将机械产品的装配模型抽象成两个两件的逐层级联关系,从而对零件模型数据进行装配适应性重构,建立起装配节点上的数据继承、传递和零件驱动关系,实现设计参数和几何模型参数的匹配和连接,从而达到整机产品的参数化设计目的,并以减速箱产品为实例,采用Pro/E系统实现了该装配体的参数化设计.     

滚动轴承参数化设计关键技术研究

Pro/ENGINEER是应用广泛的CAD/CAM/CAE集成软件系统,在Pro/ENGINEER系统中,骨架模型可以完成产品的自顶向下设计,Program可以完成产品的参数化自动生成.通过将骨架模型技术和Program相结合,研究滚动轴承参数化建模的产品结构定义和模型控制过程,进而结合设计实例给出滚动轴承参数化设计的详细步骤.结果表明这种设计方法能够实现滚动轴承的多样化和系列化设计,大大缩短滚动轴承的产品开发周期.     

汽轮发电机定子绕组参数化建模方法研究及系统开发

针对汽轮发电机定子端部绕组结构的复杂性提出了用圆锥面展开图实现空间三维形状的线棒建模方法.通过分析绕组的结构及设计成型和组装原理,建立了线棒参数化建模及装配的数学模型,并给出了三维建模的关键步骤,在此基础上结合二次开发技术、计算机编程技术以及数据库技术设计开发了基于UG/NX平台的汽轮发电机定子端部绕组参数化自动建模系统.以某百万千瓦级汽轮发电机定子端部绕组为例,验证了该建模方法及参数化自动建模系统的有效性和可行性.     

小卫星装配建模与仿真的实现

采用基于模板的参数化特征建模方法，基于数据库驱动，主控零件驱动以及系统全关联数据结构的变形设计方法，基于装配规划和动画技术的装配仿真方法，基于多媒体技术和一次开发技术的用户界设计方法，在Pro/ENGINEER环境下实现了小卫星的参数化特征建模、变形设计、零件与装配的联动设计、装配仿真、干涉性检验和用户界面设计等。     

基于参数化设计的三维桥梁模型构建

参数化设计是几何体建模的重要手段,而桥梁的三维可视化是当今桥梁信息化的发展趋势。论文针对桥梁外观参数化模型可视化的需要,对几何体参数化建模的原理和方法进行了深入探讨。结合桥梁结构特点,分析了主要桥梁组件结构(如T梁、盖梁柱式墩、轻型桥台等)构件图的几何和拓扑关系,对组件进行了参数化设计,实现组件的三维建模;并对组件中特殊图元(如圆弧倒角形墩柱、桥台近似锥面护坡)的绘制算法进行详细研究;根据各组件间空间位置的拓扑关系,利用参数化变量驱动计算各组件空间位置坐标,进行桥梁的快速拼接。完成的桥梁三维参数化建模以参数为驱动,用户可以对设计结果进行可视化修改。所实现的三维参数桥梁可视化系统具有模型构建精致,参数化建模彻底、建模速度快,参数分类清晰,可视化效果好的特点。     

利用关联关系的标准件参数化设计方法

分析了产品几何建模的参数化设计方法,提出了一种基于关联关系的标准件参数化设计方法。阐述了参数化设计方法的原理,即采用关联参数建立多个组件间的关联,以实现标准件的参数化设计。利用CATIA平台,给出了圆锥滚子轴承基于关联关系的参数化设计过程,证明了该设计方法的可行性。     

基于参数化建模的控温包装传热仿真系统开发

目的 开发控温包装传热仿真系统Tpackage,通过参数化建模和传热仿真,对控温包装的保温效果进行有效分析。方法 以典型控温包装为研究对象,基于OpenCASCADE、QT与VTK设计控温包装参数化建模模块;分析包装内外热量传递规律,开发控温包装传热求解器模块。集成2个模块实现控温包装的参数化建模和传热过程的数值模拟。结果 使用Tpakcage在30、40 ℃ 2个环境温度下对2套控温包装系统(TC1、TC2)进行传热仿真,并采用Comsol进行同条件模拟,产品测温点到达8 ℃所经过时间的最大误差分别为7.04%(TC1-30 ℃)、9.87%(TC1-40 ℃)、8.82%(TC2-30 ℃)、9.73%(TC2-40 ℃);在30 ℃条件下进行实际验证实验,通过Tpackage进行同条件对比验证,产品测温点到达8 ℃所用时间的最大误差为9.47%。结论 Tpackage能够实现典型控温包装的参数化建模,并有效评估控温包装的温度场分布。该研究可为控温包装优化设计提供参考,提高控温包装设计效率。     

汽车制造业中的CAD/CAE/CAM集成应用

以研究院所和企业的合作事例为基础,将汽车车身覆盖件拉深模具CAE分析模型的几何信息到通用CAD/CAM平台的顺畅传递,以及应用CAM系统对模具进行数控加工建模与仿真的实现过程做实例,表明了在国内汽车设计制造企业中实现CAD/CAE/CAM集成应用的可行性和有效性.     

Simulation-enabled casting product defect prediction in die casting process

In current casting industries, product development paradigm is shifting from traditional trial-and-error in the workshop to CAE-enabled simulation and ‘proof-of-concept’ by computer. The product development paradigm shift is thus from heuristic know-how and experience to more scientific simulation, evaluation, analysis and calculation. CAE simulation plays an important role in the new product development paradigm as it models the entire casting process and reveals the dynamic behaviour of the casting system in working conditions. In addition, the product quality panorama and product defects are explored via simulation in such a way that the root-causes of casting defects are pinpointed and the solutions to avoid them can be determined. In this paper, the CAE technology for casting process simulation is presented. The modelling of the casting process is first articulated and the detailed simulation issues are then described. The information related to the filling and solidification process and after-ejection behaviour are revealed by CAE simulation. Through case studies, how the CAE simulation helps identify and predict the process-related defects is illustrated and its efficiency is finally validated.     

CAE FOR THE MANUFACTURING ENGINEER: THE ROLE OF PROCESS SIMULATION IN CONCURRENT ENGINEERING

As America refocuses its attention on the factory, design and manufacturing engineers must work together closely to design the appropriate products, and matching production process in a team effort. By building off the designer's CAE tools that predict product performance, the manufacturing engineer is today able to simulate the proposed production process. Process simulations for the following manufacturing processes are available or being developed:

▪Forging, ▪Machining, ▪Injection Molding, ▪Die Casting, ▪Investment Casting, ▪Metal Forming, ▪Heat Treating, ▪Assembly Tolerancing

By utilizing the same 3-D solid model and finite element modeling tools used by the designer, coupled to powerful analysis simulation tools to predict the transient nonlinear heat transfer and plastic material flow found in many manufacturing processes, the manufacturing engineer is able to explore alternative processing plans, evaluate trade-offs and even influence the design to produce superior products.

Process simulation brings a science to support the manufacturing engineers experience for reduced lead time, lower cost, increase product quality and better understanding of the process. The next step will be to directly link the process simulation to an expert system.

This paper describes the current state of technology in the area of manufacturing process computer simulation for a number of manufacturing operations and suggests how these tools can be used “up-front” and lead to concurrent engineering.     

气囊着陆缓冲系统冲击动力学模型修正方法

针对气囊着陆缓冲系统的冲击动力学模型修正问题,首先建立了典型气囊着陆缓冲系统的冲击动力学仿真分析模型,考虑到结构动力学模型和气囊模型的相互独立性,提出对回收舱模型和气囊系统模型分别进行修正的分级修正思路;其次定义了关键点处冲击响应,解决了试验数据采样频率和试验触发不一致带来的计算结果与试验结果比较问题;就气囊着陆缓冲系统冲击动力学响应的典型特征,定义冲击响应置信因子评价计算结果与试验结果之间的吻合程度;以关键点冲击响应的试验数据与计算结果之间的误差范数作为修正目标函数,引入增广径向基函数构造修正变量关于修正目标的代理模型,将模型修正问题转换为优化问题进行求解;最后,通过典型气囊着陆缓冲系统冲击动力学试验和计算验证了所提方法的有效性。     

汽车前地板纵梁高强钢应用及回弹控制技术

目的研究造型相对复杂的前地板纵梁高强钢(HSS)应用回弹变形特点,探寻回弹控制方法。方法借助CAE分析技术,对零件进行全工序和回弹仿真分析,深入探讨零件回弹特点,提出回弹整改控制措施。结果通过整改措施的落实,样件尺寸精度达到1 mm控制要求,零件平均合格率达到90%以上,满足质量要求。结论数值仿真分析可以对零件的成形性及回弹进行预测,为工艺设计及模具开发提供有益参考。提出的回控制技术可用于指导同类型高强钢零件的模具开发工作。     

动态仿真在车身覆盖件成形中的应用

阐述了动态仿真在车身覆盖件成形领域实用化的三个关键要素：成功案例的数字化,高效的优化算法,新型的等效拉深筋阻力模型,给出了动态仿真在成形性评价,汽车板选材,拉深筋优化设计方面的应用实例,以期有助于汽车界更好地动态仿真这个先进的CAE分析工具。     

Feature-based CAD-CAE integration model for injection-moulded product design

One prominent characteristic of product design for injection-moulded parts is that design and analysis (e.g. flow simulation) go hand in hand to ensure that the design is manufacturable by the injection-moulding process. Despite the wide use of CAD and CAE systems, the two processes are still not integrated. There is no generic, unified model that allows both design and analysis information to be specified. In this paper, a feature-based CAD-CAE integration model is proposed to tackle the problem. The model comprises a hierarchy of CAD-CAE features such as part, wall, hole, rib, boss and treatment. The features are defined by their attributes and behaviours. With this model, information relating to both design and analysis can be specified and modified. The specified information from the design process is used to activate relevant CAE analysis routines, thus supporting integration from the CAD to the CAE process. If any of the specified design constraints is not satisfied from the CAE results, the initial model can be modified and the CAE analysis executed again. Hence, the model also supports integration from the CAE to the CAD process. A design case illustrates the bidirectional integration process.     

基于HyperWorks的CAE流程自动化系统设计开发

针对企业应用HyperWorks进行CAE分析时存在操作复杂和操作者需熟悉系统功能的问题,给出了基于HyperWorks、Process Manager和Process Studio的HyperWorks CAE流程自动化系统的结构及其开发流程,应用Tcl/Tk程序设计技术开发出产品零件CAE流程自动化系统。并以某零件CAE分析实例,验证自动化系统可操作性。为产品设计、分析提供一种快捷方法,缩短了企业产品设计分析周期。对企业开发工作具有一定的指导意义。