[工学]NX_CAE讲座.ppt

NX CAE讲座之 陆海燕 高级技术顾问 西门子产品管理软件公司 NX Advanced FEM+ Nastran结构分析 linear static solution Linear static analysis is used to determine the displacements, stresses, strains, and forces in structures or components caused by static loads. Elements that can be used for a linear static analysis include: 3D tetrahedral or hexahedral solid elements 2D quadrilateral or triangular thin shell elements 1D bar, beam, rod, rigid link, and spring elements 0D concentrated mass elements Gap elements Isotropic material properties are the same in all directions. Orthotropic material properties are defined relative to three perpendicular directions. Anisotropic materials also have properties that depend on direction. When an anisotropic material is fully defined (21 independent elastic constants), there is coupling between the shear and normal terms and between the shear terms. Fluid materials define material properties for liquids and gases. Hyperelastic materials specify material properties for use in a fully nonlinear hyperelastic analysis. Natural frequencies and mode shapes are the primary results for a modal solution. The results are ordered by frequency, with the lowest natural frequency being the first mode shape, the next highest being the second mode, and so on. The normal modes represent dynamic states in which the elastic and inertial forces are balanced when no external loads are applied. The magnitude of the mode shapes is arbitrary. The amplitude of the displacement is not significant, but the relative displacement of the nodes is significant. Mode shapes help you determine what load locations and directions will excite the structure. Thermal analysis: Can verify the design of a part that must function over a broad range of temperatures. Can simulate conduction, convection, and simple radiation. There is no view factor calculation. Assumes a steady state, meaning that temperatures do not vary with time. Materials used in thermal analysis include properties such as the following: Reference Temperature Use this to calculate the delta T used with the thermal expansion coefficient. If reference temperature is not specified, the default solution temperature is used. Thermal Expansion Coefficient Use this if you plan to calculate thermal strain in a later linear static analysis. Thermal Conductivity Use this to calculate energy transfer through the material. You can define these properties as tables to make them temperature-dependent. Thermal stress analysis A thermal stress analysis can optionally use thermal results as pre-load input for a structural analysis. To use the pre-load attributes for NX Nastran: In the Simulation Navigator, right-click the subcase in the structural solution, and choose Edit Solution Step. Under Temperature Pre-Load, choose NASTRAN Temperatures. Browse and select the NX Nastran *.op2 file, which contains the temperature results. For results from NX Thermal, set the Temperature Pre-Load type to NX Thermal Temperatures. Understanding a pre-load When you specify a pre-load, the solver: Reads the nodal temperature data from the selected output file. Applies the temperatures to the nodes of the structure. The meshes must be identical for NX Nastran, but are not required for NX Thermal. Uses the strain free temperature from the material data or the solution attributes for the delta T calculation. Uses the structural material properties, together with any existing structural loads. Buckling analysis: Determines buckling loads and buckled mode shapes. A buckling load is the critical load at which a structure becomes unstable. A buckled mode shape is the characteristic shape associated with a structures buckled response. Identifies the critical load factor, which is the value that can be multiplied by the applied load to cause buckling. The buckling analysis incorporates the stiffness due to the part geometry, material properties, and the applied loads and constraints. represents the stiffness of the initial configuration, and is computed from the initial part geometry and the linear material stiffness. represents the stress stiffness due to the applied loads and constraints. represents the critical load factor multiplier (eigenvalue). represents the buckled mode shape (eigenvector). In NX Nastran, a buckling solution includes a buckling loads subcase and a buckling methods subcase An SESTATIC 101 linear static solution: Calculates the element stiffness (K) matrix once at the beginning of the solution. Assumes Hookes law, Force = K U, to calculate displacements (U). Does not account for large displacements and rotation. Will not update pressure load directions. An NLSTATIC 106 or ADVNL 601, 106 solution with geometry nonlinear conditions: Iterates to follow a nonlinear force/displacement path. Periodically updates the element stiffness matrix while following the nonlinear force/displacement path. Uses a strain definition which accounts for large displacements and rotations. Uses the current configuration of a deformed structure to determine the direction of pressure loads. A stiffness change may be a result of both geometry and material nonlinear effects if both are included in the analysis. Boundary conditions for solution types NLSTATIC 106 and ADVNL 601, 106 can be geometry-based or finite element-based. Examples include: Displacement constraints. All loads, but only pressure loads are updated in geometry nonlinear. Surface-to-surface gluing. Surface-to-surface contact is supported for ADVNL 601, 106, but not for NLSTATIC 106. 议程 NX 高级有限元仿真流程简介 NX CAE结构分析案例 NX Nastran结构分析功能介绍 Page 14SIEMENS PLM Software Any Design SeatAny Design Seat Add-on Simulation to any Mach Design Seat NX Best Practice Design Wizards NX Design Simulation NX Motion Simulation NX6 CAE产品全貌 NX Advanced Simulation NX Advanced FEM Standalone No Solver Standalone With Solver Add-on Advanced Simulation to any Mach Simulation Seat NX Nastran Simulation Environments NX Thermal Simulation NX Flow Simulation NX Electronic Systems Cooling NX Laminate Composites NX Response Simulation NX Advanced Thermal Simulation NX Advanced Flow Simulation NX Space Systems Thermal NX Simulation Process Studio Standalone Simulation SeatsStandalone Simulation Seats NX Advanced NX Advanced FEMFEM NX Advanced NX Advanced SimulationSimulation NX Motion Control NX Model Correlation Page 15SIEMENS PLM Software NX 高级仿真分析包功能 前处理：网格+边界条件+求解设定 NX Advanced FEM Ansys NX&MSC/Nastran Abaqus LSDYNA 求解功能 （NX Nastran 无求解规模限制）： 线性静态分析（含惯性释放） 模态分析 屈曲分析 稳态热传导 瞬态热传导 点焊分析 后处理 云图 XY图线 分析向导 强度分析向 导 振动分析向 导 Page 16SIEMENS PLM Software 缩短FE建模/网格划分时间 改进FEA求解时间 跟踪工程数据 提早开始系统级CAE分析 NX CAE的价值流程创新 Solve Mesh Look for inform ation Create geome try Loads BCs Mesh Create geometry Look for information Loads BCs Part Design Create geometry Export & repair design geometry CAE分析流程对比 NX CAE分析流程给企业带来的价值 Page 17SIEMENS PLM Software NX 高级仿真独创 CAD&CAE一体化流程 几何 CAE 模型 求解 结果查看 载荷和边界 报告与结论 迭代与优化（ 如果有需要） 理想化模型 前处理后处理 CAD数据无需转化到CAE平台 几何处理方式多样灵活 网格划分高效 CAE模型与CAD参数关联更新! 高级仿真和设计仿真提供分级解决方案 Page 18SIEMENS PLM Software NX CAE的价值结构创新 NX NX 软件最先提出多级仿真数据结构软件最先提出多级仿真数据结构 优点： 1 各层数据柔性映射 2 追踪简化模型与主模型的变更关系 3 柔性化数据管理和模型重用 4 为有效的CAE数据管理提供保证 主模型CAD文件 理想化CAD文件 FEM文件(网格） 仿真文件（载荷， 工况等） Page 19SIEMENS PLM Software NX-Advanced Simulation文件结构 分级数据结构支持有效的数据管理 Master Part Idealize Part FEM 1 FEM 2 SIM1 Idealize Part SIM2 FEM 3 FEM 4 Page 20SIEMENS PLM Software NXCAE 曲柄仿真分析流程演示 Page 21SIEMENS PLM Software NX CAE的价值网格划分 装配有限元提高效率 5x 10x 更快的进程 团队可以同时在装配体不同的部件上 工作 系统集成器可以集成供应商提供的模 型 自动映射组件位置和方向 x 4 多个共用组件只需要一个网格模型 如何才能像重用几何体一样重用分析模型？ Page 22SIEMENS PLM Software NX解决方案 参数化概念从CAD延伸到CAE领域！ CADCAE 设计特征 参数/表达式 模型历史 装配树 设计意图 版本历史 无缝 传递 仿真结果 边界 网格参数驱动 自动更新 NX Pro/E, Catia, SE 后参数化 快捷重用 CAE模型 我们期望是 突破常规CAE流程壁垒！ （后）参数化 CAD建模 数据管理平台TC for Simulation Page 23SIEMENS PLM Software 热成像仪结构分析案例 零件级结构分析 组件结构振动分析 Page 24SIEMENS PLM Software NX CAE分析向导动画演示 Page 25SIEMENS PLM Software 通过重用提高效率 为什么需要等待几何体被改变？ 更加直观的按照意愿修 改几何体意味着更快的 反馈 模型按照期望的形式更新，并且 几何数据和分析模型保持关联 同步建模只需选择 面 点击两次鼠标 就可以改变或移动 特征 Page 26SIEMENS PLM Software NX Response Simulation振动分析 分析类型 瞬态响应 频域响应 随机响应 冲击谱响应 DDAM响应 传递函数 独特优势 GUI驱动计算 快速得到结果 图表与云图显示 支持与实验的校验 激励载荷生成工具 实验载荷转化工具 Page 27SIEMENS PLM Software 动力响应分析 NX特有的快速方便地动力响应工具 1: 准备有限元模型 创建或者读入 施加边界条件 2: 模态模型建立 计算用于动力响应的模态SOL 103RS （新增模态算法） 3: 定义事件 瞬态,频率，随机，谱分析 激励：点载荷，分布载荷，强迫运动等 4: 评估响应 云图 or XY-plots NX 前后处理器 NX Nastran NX 动力响应 分析 Page 28SIEMENS PLM Software NX动力响应分析 n响应分析 u Attaches RS to OP2 file u Define damping n函数管理器 Create, edit, copy functions to be used for loading n传感器 u Set of pre-defined locations for response calculation n事件 u Define dynamic analysis type n函数工具 Function operators for creation, conversion, import, other processing Java toolkit Allows user-defined function operators n激励 u Concentrated loads u Distributed loads u DDAM loads n函数数学运算 (FTK) Single math Multi math Overall math Min/Max Generators Page 29SIEMENS PLM Software 振动分析演示动画 Page 30SIEMENS PLM Software NX Nastran 企业版和桌面版 独立的解算器,采用浮动的授权许可证 版本历史 NX Nastran 1 20032003年年 9 9 月月 NX Nastran 2 20042004年年 4 4 月月 NX Nastran 3 20042004年年1212月月 NX Nastran 4 20052005年年1010月月 NX Nastran 4.1 20062006年年 2 2 月月 NX Nastran 5 20072007年年 2 2 月月 NX Nastran 5.1 20072007年年 9 9 月月 NX Nastran 6 20082008年年 4 4 月月 NX Nastran Page 31SIEMENS PLM Software 分析类型 Steady state or Transient Material, Large deflection, Contact Static Buckling Fluid-flow Thermal Acoustics Electromagnetic Response Time domain Frequency domain Structural Non-structural Linear Nonlinear Linear Nonlinear Dynamics Durability Time domain Frequency domain FEA Direct Modal Normal ModesComplex ModesEigenvalue Optimization Page 32SIEMENS PLM Software NX NastranNX Nastran所支持的求解类型所支持的求解类型 Steady state or Transient Material, Large deflection, Contact Static Buckling Fluid-flow Thermal Acoustics Electromagnetic Eigenvalue Response Time domain Frequency domain Structural Non-structural Linear Nonlinear Linear Nonlinear Dynamics Durability Time domain Frequency domain FEA Direct Modal Normal ModesComplex Modes Supported by NX Nastran Add-on Option Optimization Page 33SIEMENS PLM Software NX/NASTRAN的独特优势 极高的软件可靠性 NASTRAN是一具有高度可靠性的结构有限元分析软件, 有着40年的开发和改进 历史, 并通过50,000多个最终用户的长期工程应用的验证。 NX NASTRAN的整个研制及测试过程 是在 Siemens 公司的QA部门、美国国防 部、国家宇航局、联邦航空管理委员会(FAA)及核能委员会 等有关机构的严 格控制下完成的,每一版的发行都要经过4个级别5,000个以上测试题目的检验 。 Page 34SIEMENS PLM Software NX/NASTRAN的独特优势 优秀的软件品质 NX NASTRAN的计算结果与其它质量规范相比已成为最高质量标准, 得到有限 元业界的一致公认。通过无数考题和大量工程实践的比较,众多重视产品质量 的大公司和工业行业都用NASTRAN的计算结果作为标准代替其它质量规范。 Page 35SIEMENS PLM Software NX/NASTRAN的独特优势 作为工业标准的输入/输出格式 NX NASTRAN 被人们如此推崇而广泛应用使其输入输出格式及计算结果成为当 今CAE工业标准,几乎所有的CAD/CAM系统都竞相开发了其与NASTRAN的直接接 口, NASTRAN的计算结果通常被视为评估其它有限元分析软件精度的参照标准 ,同时也是处理大型工程项目和国际招标的首选有限元分析软件。 Page 36SIEMENS PLM Software NX/NASTRAN的独特优势 强大的软件功能 NX NASTRAN不但容易使用而且具有十分强大的软件功能。 通过不断地完善, 如增加新的单元类型和分析功能、提供更先进的用户界面和数据管理手段、 进一步提高解题精度和矩阵运算效益等等 。 Page 37SIEMENS PLM Software NX/NASTRAN的独特优势 高度灵活的开放式结构 NX NASTRAN全模块化的组织结构使其不但拥有很强的分析功能而又保证很好 的灵活性, 用户可针对根据自己的工程问题和系统需求通过模块选择、组合 获取最佳的应用系统。此外, NX NASTRAN的全开放式系统还为用户提供了其 它同类程序所无法比拟开发工具DMAP语言。 Page 38SIEMENS PLM Software NX/NASTRAN的独特优势 无限的解题能力 NX