UG有限元高级仿真--真正有用的资料.doc

高级仿真高级仿真1NX Nastran structural analysis and solution types2NX Nastran thermal analysis and solution types4线性静态分析4Supported linear static analysis types4Using materials for a linear static analysis5Defining boundary conditions for a linear static analysis5Using the iterative solver5模态分析6Supported modal analysis types6Using materials for a modal analysis7Defining boundary conditions for a modal analysis7Setting modal solution attributes7Reviewing modal analysis results8如何判断模态的频率9线性曲屈分析9Buckling analysis introduction9Linear buckling assumptions10Supported buckling analysis types10Using materials for a buckling analysis10Defining boundary conditions for a buckling analysis10Reviewing buckling analysis results11Nonlinear static analysis introduction11Supported nonlinear solution types12Whether to use a nonlinear solution12Using elements for solution type NLSTATIC 10613Using elements for solution type ADVNL 601, 10613Using materials for solution types NLSTATIC 106 and ADVNL 601, 10614Entering stress/strain data for solution types NLSTATIC 106 and ADVNL 601, 10614Defining boundary conditions for solution types NLSTATIC 106 and ADVNL 601, 10615NLSTATIC 106的求解设置15ADVNL 601, 106的求解设置16响应仿真17仿真步骤17Special boundary conditions18Solution attributes for Response Simulation20FRF and Transmissibility20Analysis events21Excitation loads22Function tools for Response Simulation utility22Sensors23Strain gages23产生整个模型在极值点处的响应24柔体分析24Flexible bodies workflow24Advanced Simulation steps24Motion Simulation steps25Connecting the flexible body FEM to the mechanism25Defining connection and load degrees of freedom25NX Nastran structural analysis and solution typesAnalysis typeSolution typeDescriptionLinear StaticSESTATIC101 Single ConstraintSESTATIC101 Multi-ConstraintSESTATIC101 SuperelementStructural solve used to solve linear and some nonlinear problems, such as gaps and contact elements. Modal AnalysisSEMODES103 SEMODES103 Response SimulationSEMODES103 SuperelementSEMODES103 Flexible BodyEvaluates normal modes and natural frequencies. Linear BucklingSEBUCKL105Determines buckling loads and buckled mode shapes. Nonlinear StaticsNLSTATIC106Considers geometric and material nonlinear behavior. Direct Frequency ResponseSEDFREQ 108Frequency response is calculated directly (without normal modes). Direct Transient ResponseSEDTRAN 109Transient response is calculated directly (without normal modes). Modal Frequency ResponseSEMFREQ 111Frequency response is based on previously solved normal modes. Modal Transient ResponseSEMTRAN 112Transient response is based on previously solved normal modes. Nonlinear Transient ResponseNLTRAN 129Dynamic transient response is calculated, which includes (NLSTATIC 106) nonlinear conditions.Advanced Nonlinear Statics (implicit)ADVNL 601,106Considers geometric and material nonlinear behavior. Advanced Nonlinear Transient Response (implicit)ADVNL 601,129Dynamic transient response is calculated, which includes nonlinear conditions.Advanced Nonlinear Dynamic Analysis (explicit)ADVNL 701Calculates dynamic responses with nonlinear effects.Design OptimizationDESOPT 200Adjusts the defined design variables within the limits you specify as it searches for the optimum conditions, while working in the scope of your overall optimization objective and output constraints.Axisymmetric StructuralSESTATIC101 - Multi-ConstraintNLSTATIC106ADVNL 601,106ADVNL 601,129Solves an FE model that is defined for only a section cut on one side of the axis of an axisymmetric part. This greatly reduces the degrees of freedom (DOF) and hence also significantly reduces solution time.NX Nastran thermal analysis and solution typesAnalysis typeSolution typeDescriptionSteady State Heat TransferNLSCSH153Thermal analysis.Axisymmetric ThermalNLSCSH153 Thermal analysis for an FE model that is defined for only a section cut on one side of the axis of an axisymmetric part. 线性静态分析Supported linear static analysis typesIn Advanced Simulation, you can choose from the following linear static analysis types when you create a structural solution. SolverSolution typeNX NastranMSC NastranSESTATIC101 - Single ConstraintNX NastranMSC NastranSESTATIC101 - Multi-ConstraintANSYSLinear StaticsABAQUSStatic Perturbation substepUsing materials for a linear static analysisMaterial types that can be used in a linear static analysis include: Isotropic Orthotropic Anisotropic Laminate Defining boundary conditions for a linear static analysisBoundary conditions for linear static analysis can be geometry-based or finite element-based. Examples include: Point and edge forces Face loads Temperature loads Displacement constraints Coupled degrees of freedom Using the iterative solverYou can turn on the Element Iterative Solver option on the Solution dialog box, or when you are prompted after you start a solve. The iterative solver: Can be faster, uses less memory, and has fewer disk requirements than the standard sparse matrix solver. Can be used for a linear static analysis that does not include contact. Shows the best performance gain with models composed mostly of solid elements. Is very efficient for models composed mostly of parabolic tetrahedral elements. 模态分析Supported modal analysis typesIn Advanced Simulation, you can choose from the following modal analysis types when you create a structural solution: SolverSolution typeNX NastranSEMODES 103SEMODES 103 - Response SimulationSEMODES 103 - SuperelementSEMODES 103 - Flexible BodyMSC NastranSEMODES 103SEMODES 103 - SuperelementANSYSModalABAQUSFrequency Perturbation substepUsing materials for a modal analysisMaterial types that can be used in a modal analysis include: Isotropic Orthotropic Anisotropic FluidDefining boundary conditions for a modal analysisBoundary conditions for modal analysis include constraints and gluing, such as: Displacement constraints. Coupled degrees of freedom. Surface-to-surface gluingSetting modal solution attributesFor a modal analysis, some of the NX Nastran solution attributes include: Max Job Time Output Requests Real Eigenvalue Extraction Data. Identifies the type of solve: Lanczos or Householder. Lanczos Method or Householder Method. The method specifies the real eigenvalue extraction options for the solution. Eigenvalue extraction options are stored as a solver-specific object. Lanczos is the recommended method for most models; Householder is recommended for smaller models. The options include frequency range lower and upper limits, and the number of desired modes. Default TemperatureFor more information, see Solvers and SolutionsSetting Nastran Solution Options in the Advanced Simulation online Help. Reviewing modal analysis resultsNatural 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.如何判断模态的频率The first 6 modes have extremely low frequencies. These are rigid body modes. Mode 7 represents the first flexible mode with a natural frequency of about 133 Hz.线性曲屈分析Buckling analysis introductionBuckling analysis: Determines buckling loads and buckled mode shapes. o A buckling load is the critical load at which a structure becomes unstable.o 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. Linear buckling assumptionsThe buckling analysis uses linear theory. The following assumptions and limitations apply: The deflections prior to buckling are small. The reference equilibrium configuration is the initial geometry of the part. The response of the structure prior to buckling exhibits a linear relationship between stress and strain. Post-buckling behavior is not predictedSupported buckling analysis typesIn Advanced Simulation, you can choose from the following buckling analysis types when you create a buckling solution:SolverSolution typeNX NastranMSC NastranSEBUCKL 105ANSYSBucklingABAQUSBuckling Perturbation SubstepUsing materials for a buckling analysisMaterial types that can be used in a buckling analysis include: Isotropic Orthotropic Anisotropic Defining boundary conditions for a buckling analysisFor a buckling analysis:1. Define constraints. Constrain the model as you would for a linear static analysis.2. Apply loads. The load set can contain more than one load type (Force, Pressure), but every load will be scaled by the load factor. A magnitude of 1 is often used when a single load type will cause the model to buckle.Reviewing buckling analysis resultsFor NX Nastran results, buckling analysis results are listed as: A set of static analysis results for the buckling loads subcase. A set of modes for the buckling methods subcase. o Each mode has an eigenvalue (load factor) listed.o The applied load multiplied by the buckling load factor is the load at which the part will buckle. o The first mode has the lowest buckling load factor and is usually the mode of most interest. o If the buckling load factor is below 1, the part has buckled. 如果eigenvalue小于1，那么这个模型就已经发生曲屈。The critical load is the product of the applied load and the eigenvalue for Mode 1.比如在本例中施加的载荷为1N,而Mode 1的对应值为1380，那么这个临界载荷为1x1380N.Nonlinear static analysis introductionThe nonlinear solution types NLSTATIC 106 and ADVNL 601, 106 are capable of simulating the following conditions: geometric nonlinear, material plasticity, and hyperelasticity.This introduction presents two of these nonlinear conditions: Material plasticity Material data is entered that describes both the linear elastic and the plastic yield portion of the stress strain curve. Geometric nonlinear Pressure loads and element stiffness are updated as the solution iterates. Large geometry displacements and rotation are supported.NLSTATIC 106 and ADVNL 601, 106 solutions can include material plasticity and geometric conditions separately or simultaneously.Supported nonlinear solution typesIn Advanced Simulation, you can choose from the following nonlinear solution types when the Analysis Type is set to Structural. SolverSolution typeNX NastranNLSTATIC 106ADVNL 601, 106ADVNL 601, 129ADVNL 701MSC NastranNLSTATIC 106ANSYSNonlinear StaticsABAQUSGeneral AnalysisWhether to use a nonlinear solutionAn 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 geometric nonlinear conditions: Iterates (迭代)to follow a nonlinear force/displacement path. Periodically （定期的）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.几何非线性Using elements for solution type NLSTATIC 106For solution type NLSTATIC 106, nonlinear elements may be combined with linear elements for computational efficiency if the nonlinear effects can be localized.The supported nonlinear elements include: 3D 4-noded and 10-noded tetrahedral solid elements. 3D 8-noded hexahedral solid elements. 3D 6-noded pentagonal solid elements. 2D 4-noded quadrilateral or 3-noded triangular thin shell elements. 1D 2-noded bar, beam, rod, and spring elements. GAP elements are created when “contact mesh” or “surface contact mesh” mesh mating conditions are defined. NLSTATIC 106 solution treats the GAP element as a nonlinear gap element in which the gap conditions update as the nonlinear solution iterates.Using elements for solution type ADVNL 601, 106For solution type ADVNL 601, 106, the supported nonlinear elements include: 3D 4-noded and 10-noded tetrahedral solid elements. 3D 8-noded and 20-noded hexahedral solid elements. 3D 6-noded and 15-noded pentagonal solid elements. 3D 5-noded and 13-noded pyramid solid elements. 3D 4-noded and 8-noded or 3-noded and 6-noded axisymmetric thin shell elements. 2D 4-noded and 8-noded quadrilateral or 3-noded and 6-noded triangular thin shell elements. 1D 2-noded bar, beam, rod, and spring elements. RBE2 and RBE3 elements. 0D concentrated mass elements. Gap elements.Using materials for solution types NLSTATIC 106 and ADVNL 601, 106Material types that can be used in the solution type NLSTATIC 106 include: Isotropic with or without elastic/plastic properties. Anisotropic for geometric nonlinear only. Hyperelastic properties that can be assigned directly to the physical properties for PLPLANE (2D elements) or PLSOLID (3D elements).Material types that can be used in the solution type ADVNL 601, 106 include: Isotropic. Orthotropic. Hyperelastic properties that can be assigned directly to the physical properties for PLPLANE (2D elements) or PLSOLID (3D elements).Entering stress/strain data for solution types NLSTATIC 106 and ADVNL 601, 1061. Create a new isotropic material.2. In the Stress-Strain Related Properties group, select Field from the Stress-Strain (H) list. 3. From the Specify Field list, select Table Constructor . 4. Enter a value of 0,0 for the first data point. For the second point, enter a value that corresponds to the yield point. You can also define additional data points.5. In the Isotropic Material dialog box, enter an Initial Yield Point (LIMIT 1) value. This value must match the second stress value in the stress-strain table. Defining boundary conditions for solution types NLSTATIC 106 and ADVNL 601, 106Boundary conditions for solution types NLSTATIC 106 and ADVNL 601, 106 can be geometry-based or finite element-based. Examples include: Displacement constraints. All loads. Only pressure loads are updated in geometric nonlinear. Surface-to-surface gluing.Surface-to-surface contact is supported for ADVNL 601, 106, but not for NLSTATIC 106.NLSTATIC 106的求解设置 Large Displacements Includes nonlinear geometry effects. Intermediate Output Determines if output is stored for every converged load increment, or only at the final increment for each subcase. Number of Increments Subdivides all subcase loads by the value entered. This can be increased if a solution has problems converging. ADVNL 601, 106的求解设置solution control and strategy in ADVNL 601,106 are set under the Case Control tab/Strategy Parameters. Some examples are: Analysis Control Setting the Automatic Incrementation Scheme to ATS automatically subdivides time steps that fail to converge. Equilibrium Can be used to adjust the default convergence options and tolerances. Also, the line search iteration scheme can be selected here. Contact Controls contact options for all contact sets. 响应仿真主要就是用于确定结构模型对于一系列载荷工况的动态或静态响应仿真步骤StepSummary1. Build the finite element (FE) model.Define the geometry, material properties, mesh, and constraints, as you would for other structural solution types. Also, specify the locations of your excitations and define any static and dynamic loads. 2. Create the NX Nastran solution.Create an NX Nastran SEMODES 103 Response Simulation solution. You can also use an SEMODES 103 solution, but it generates only the normal modes. 3. Solve the model.NX Nastran generates normal modes, constraint modes, attachment modes, and other modal information.4. Create the Response Simulation. After solving the model, create the Response Simulation solution process. 5. Review the mode shapes.Review the mode shapes in the Post-Processing Navigator or in the Response Simulation Details View subpanel in the Simulation Navigator. 6. Define the damping values for each mode. In the Response Simulation Details View subpanel, you can add viscous and hysteretic damping. 7. Create an event.Define the type of response simulation you will perform, such as transient or frequency. The event combines the modal model and your excitation functions. 8. Create excitation functions.Excitations define the loading for the response simulation, such as a vehicles tires following a bumps profile. 9. Analyze the models dynamic responses to the excitations.Depending on the type of response you are evaluating, the software calculates and stores the results in response functions or response results sets. Response functions each contain one response (for example, stress at one node) as a function of time or frequency. You can plot these function records in the NX graphics window. Response results sets each contain responses for multiple nodes or el