僅自由振動響應之模態分析線上量測系統之發展與應用

Development and Application of On-line Measurement System for Modal Analysis by Free Vibration Response Only

趙天麒(Tien-Chi Chao)

指導教授 ： 王栢村

國立屏東科技大學/工學院/機械工程系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00211

摘要

本文目的在發展僅自由振動響應之模態分析線上量測系統，並實際以量測系統對多自由度系統與懸臂結構進行模態參數之辨識。首先，以前人所發展的僅自由振動響之模態分析(MAFVRO)方法為基礎，結合量測硬體設備，以開發其量測系統，並建置MAFVRO線上量測系統所需之模組，且製作成使用者人機介面，接著以MAFVRO方法來對多自由度系統進行模態參數之辨識，並以實驗模態分析之模態參數為基準，與MAFVRO結果來進行比較；最後，將實際所發展之量測系統應用於懸臂樑結構，探討其MAFVRO線上量測之適應性。本文所發展之MAFVRO線上量測系統，與傳統實驗模態分析之量測形式不同，其突破以往實驗模態分析須有已知外力之限制。本文發展之MAFVRO線上量測系統，整合了硬體與線上檢測自動化功能，往後可應用於結構破壞檢查或健康監測之用。

關鍵字

實驗模態分析 ； 僅自由振動響應之模態分析 ； 模態參數

並列摘要

This work aims to develop on-line measurement system for modal analysis by free vibration response only (MAFVRO). The developed measurement system is used to identify modal parameters of a multiple degree-of-freedom (MDOF) system and a cantilever beam structure. First, base on the theoretical model of MAFVRO the measurement hardware is set up for the measurement module. The graphic user interface (GUI) is then built to integrate the measurement and MAFVRO analysis modules. The modal identification of a MDOF system via the system is then carried out. The modal parameters are compared between experimental modal analysis(EMA) and MAFVRO methods. Finally, the application of the developed system is also applied to the cantilever beam structure for modal identification. The developed methodology does not require the known input and shows the merit other than the conventional EMA. The MAFVRO measurement system integrates the hardware for on-line automatic measurement and analysis and can be employed for future applications in structural damage detection or health monitoring.

並列關鍵字

experimental modal analysis ； modal analysis by free vibration response only (MAFVRO) ； modal parameter

參考文獻

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