ADAMS-Vibration-振动分析模块教程.ppt

内容n了解模块功能；n了解Vibration与Linear模块的区别；n使用Vibration模块进行虚拟振动试验及方案设计。Vibration Issues Facing Engineers and DesignersnHow comfortable is ride, whether in automobile, airplane, railcar, or off-road machinery?nWill excitations in one part of system interact with another part of system?nWhen problems occur, how can they be isolated?Industry Efforts and MetricsnGood vibration characteristics are purchase motivator and improve customer satisfactionnNeed good way to measure designnOptimum NVH often conflicts with other attributes such as durability or vehicle dynamic performance n Need way to balance competing requirementsnSignificant effort spent to understand and quantify customer NVH requirements into objective terms and define specific tests relating to customer eventsnCurrent methods are expensiveIndustry Efforts and MetricsnNVH involves both objective and subjective development nPart of process can be quantified with analytical toolsnSuppliers must “tune” their systems/components (right the first time) to prototype vehicle or else they are responsible for NVH resolutionnNeed way to study systemnIssues often discovered late in prototype development result in money and time lossnValue in designing right wayThe NeednA way to study system-level vibrations the same way you can now study system-level motion problemsnmuch faster!Solution: Extend Scope of Virtual PrototypingMotion/ PerformanceSafetyDurability/ FatigueNoise/Vibration1 Take your system to different operating points to analyze vibratory behavior (without having to create new models)2 Include effects of hydraulics, controls, and other subsystems on vibration characteristics3 Analyze system modes including attachment and other nonlinear characteristicsThree Reasons to Use ADAMS/VibrationAnalyze Vibratory Behavior inDifferent ConfigurationsnSatellite Example:nSystem eigenvalues shift according to nPanel deployment anglenLocking conditionnContact conditionnActual spring ratesnThis shift affects attitude control margin, pointing jitter magnitude, and structural loading conditionsAnalyze Vibratory Behavior inDifferent ConfigurationsnRailcar Example: nSystem eigenvalues shift according to nEquivalent conicitynSuspension stiffnessesnDamper characteristicsnThis shift affects railcar stability and running comfortInclude Effects of Hydraulics and Controls on System BehaviornHydraulics Example:nApply input vibration to control valve and see effect at cylinder pressure and boom movement in frequency response function plots and animationsAnalyze System Modes Including Attachment CharacteristicsnAutomotive Example:nEngine mount displacements due to combustion forces in dependency ofnEngine mount characteristicsnEngine mount positionnFrequency domain analysis helps designers improve engine mount installationsADAMS/Vibration 11.0 CapabilitiesnFrequency domain input forcing functionsnFrequency response function calculationsnModal participation tablesnForced vibration animationnForced vibration plottingnGenerate linear subsystemsHow Does It Work?Simplified/Unified ApproachMotion or VibrationSimulation ProcessInputPost-ProcessingSolutionTime or Frequency DomainInputsPlots, Animation, Tables, other time and frequency dataADAMS/Vibration Walk-ThroughnStep 1nCreate input channels, output channels, and actuatorsActuator associated with an input channelSpline defines PSDADAMS/Vibration Walk-ThroughnStep 2nRun analysisDefine inputs/outputs to useDefine operating point, frequency range, and stepsADAMS/Vibration Walk-ThroughnStep 3nPost-processingnSystem ModesnFrequency Response FunctionsnPower Spectral DensitynModal Participation Tables例子：卫星振动特性分析例子：卫星振动特性分析n系统的模态分析，且模态、振型变化例子：卫星振动特性分析n仪器的力学环境。例子：卫星振动特性分析n卫星适配器刚度阻尼如何选取？回顾及问题n了解模块功能；n了解Vibration与Linear模块的区别；n使用Vibration模块进行虚拟振动试验及方案设计。注意n在Win2000下需安装ADAMS Vibration补丁才可使用；n需设置两个系统环境变量： MDI_VIBRATION_LINEAR_SOLVE=VIBSOLVE2 MDI_VIBRATION_MODAL_PARTICIPATION =INPUT_SCALING 注意：n请安装Compaq Visual Fortran6.1A 习题nHelp文档中的例子