ADAMS_Vibration

Current methods are expensive
Industry Efforts and Metrics

NVH involves both objective and subjective development

Part of process can be quantified with analytical tools
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。

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

Issues often discovered late in prototype development result in money and time loss

Value in designing right way
The Nபைடு நூலகம்ed


A way to study system-level vibrations the same way you can now study system-level motion problems …much faster!
Analyze System Modes Including Attachment Characteristics

Automotive Example:

Engine mount displacements due to combustion forces in dependency of


Engine mount characteristics Engine mount position

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
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

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
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
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?
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
Industry Efforts and Metrics

Good vibration characteristics are purchase motivator and improve customer satisfaction

Need good way to measure design


This shift affects attitude control margin, pointing jitter magnitude, and structural loading conditions
Analyze Vibratory Behavior in Different Configurations
习题

Help文档中的例子
ADAMS/Vibration Walk-Through

Step 1

Create input channels, output channels, and actuators
Actuator associated with an input channel
Spline defines PSD
ADAMS/Vibration Walk-Through

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
Analyze Vibratory Behavior in Different Configurations

Satellite Example:

System eigenvalues shift according to

Panel deployment angle Locking condition Contact condition Actual spring rates
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