ADAMS Vibration 振动分析模块教程

Analyze System Modes Including Attachment Characteristics
Automotive Example:
Engine mount displacements due to combustion forces in dependency of
Engine mount characteristics Engine mount position
How Does It Work? Simplified/Unified Approach
Solution
Motion or Vibration Simulation Process
Input
Post-Processing
Time or Frequency Domain Inputs
Plots, Animation, Tables, other time and frequency data
Frequency domain analysis helps designers improve
ADAMS/Vibration 11.0 Capabilities
Frequency domain input forcing functions Frequency response function calculations Modal participation tables Forced vibration animation Forced vibration plotting Generate linear subsystems
Step 2
Run analysis
Define operating point, frequency range, and steps
Define inputs/outputs to use
ADAMS/Vibration Walk-Through
Step 3
Post-processing System Modes Frequency Response Functions Power Spectral Density Modal Participation Tables
This shift affects attitude control margin, pointing jitter magnitude, and structural loading conditions
Analyze Vibratory Behavior in Different Configurations
ADAMS/Vibration 振动分析模块 教程
内容
了解模块功能； 了解Vibration与Linear模块的区别； 使用Vibration模块进行虚拟振动试验及 方案设计。
Vibration Issues Facing Engineers and Designers
How comfortable is ride, whether in automobile, airplane, railcar, or off-road machinery? Will excitations in one part of system interact with another part of system? When problems occur, how can they be isolated?
Solution: Extend Scope of Virtual Prototyping
Motion/ Performance Safety Durability/ Fatigue Noise/ Vibration
Three Reasons to Use ADAMS/Vibration
1 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 characteristics 3 Analyze system modes including attachment and other nonlinear characteristics
Suppliers must “tune” their systems/components (right the first time) to prototype vehicle or else they are responsible for NVH resolution
Need way to study system
例子：卫星振动特性分析
例子：卫星振动特性分析
系统的模态分析，且模态、振型变化
例子：卫星振动特性分析
仪器的力学环境。
例子：卫星振动特性分析
卫星适配器刚度阻尼如何选取？
回顾及问题
了解模块功能； 了解Vibration与Linear模块的区别； 使用Vibration模块进行虚拟振动试验及 方案设计。
习题
Help文档中的例子
Railcar Example:
System eigenvalues shift according to
Equivalent conicity Suspension stiffnesses Damper characteristics
This shift affects railcar stability and running comfort
注意
在Win2000下需安装ADAMS Vibration补 丁才可使用； 需设置两个系统环境变量：
MDI_VIBRATION_LINEAR_SOLVE=VIBSOLVE2 MDI_VIBRATION_MODAL_PARTICIPATION =INPUT_SCALING
注意：
请安装Compaq Visual Fortran6.1A
Include Effects of Hydraulics and Controls on System Behavior
Hydraulics Example:
Apply input vibration to control valve and see effect at cylinder pressure and boom movement in frequency response function plots and animations
Analyze Vibratory Behavior in Different Configurations
Satellite Example:
System eigenvalues shift according to
Panel deployment angle Locking condition Contact condition Actual spring rates
ADAMS/Vibration Walk-Through
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Create input channels, output channels, and actuators
Actuator associated with an input channel
Spline defines PSD
ADAMS/Vibration Walk-Through
Current methods are expensive
Industry Efforts and Metrics
NVH involves both objective and subjective development
Part of process can be quantified with analytical tools
Issues often discovered late in prototype development result in money and time loss
Value in designing right way
The Need
A way to study system-level vibrations the same way you can now study system-level motion problems …much faster!
Industry Efforts and Metrics
Good vibration characteristics are purchase motivator and improve customer satisfaction
Need good way to measure design
Optimum NVH often conflicts with other attributes such as durability or vehicle dynamic performance
Need way to balance competing requirements
Significant effort spent to understand and quantify customer NVH requirements into objective terms and define specific tests relating to customer events