Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2769
標題: 相位移法在光彈上的應用
Application of Phase-Shifting Method in photoelasticity
作者: 黃兆宏
Hwang , Zhao-Hong
關鍵字: photoelasticity;光彈;phase-shifting method;isoclinic;isochromatic;plane polariscope dark field;相位移法;等傾角線;等色線;平面偏極暗場
出版社: 機械工程學系
摘要: 
本文的主旨有三。一、提出一個新的相移方法來求出主應力角。二、提出三個不堅固區偵測方式來解決相位還原時的問題。三、說明相位還原時在奇異點所面臨的問題及應對方式。在以往尋求等傾角的方法中大砥上都是採用平面偏極場與圓偏極場相除,然而在圓偏極場中有太多的參數必須考慮,故此法不甚精確,而當引入了相位移法觀念後,已可直接由數張平面偏極場求出等傾角,這個方法使我們不須考慮圓偏極場下眾多參數的變化問題;而以往國外的相關文獻均是以固定的四張或三張影像的相位移法來求得等傾角,選擇性較不高;而本文則開發出一個新的選擇方式,在理論上是可以任意角度的四張或三張影像。另外文中也採用了Dennis先生所開發的細胞自動化相位還原機[1]來做相位還原的工作,這是一個二維的相位還原機,還原結果十分完美幾乎沒有斷層產生,惟使用此還原機前必須針對不堅固區作一偵測,然而Dennis所提出的不堅固區偵測方式只有一種,並無法確實地偵測出所有的不堅固區及產生在邊界處的不堅固區,故針對此本文再另外提出三個不堅固區偵測方式以補Dennis先生之不足。另外在實驗時發現影響Dennis細胞自動化相位還原機的成功與否不僅僅是不堅固區的問題而已,還有奇異點問題,這是無可厚非的因為奇異點的等傾角原本就無法定義,故一般的方法均是將奇異點部分及其「周圍大半區域」去除,這使得我們必須犧牲奇點周圍的大半資訊,本篇論文也將提出一個奇異點的應對原則,使用此原則相信可保留大半資訊並不受奇異點問題困擾。
另外本文中對於光彈基本理論及還原理論上有淺顯深入的說明,全文的主要架構便是以理論為基礎,從而程式模擬,進而應用於實驗上。

ABSTRACT
The goal of this thesis is to propose an automatic fringe counting algorithm for photoelastic pattern, including the isoclinic as well as isochomatic fringes of photoelasticity stress pattern. There are three main tasks in the thesis. Firstly, we proposed a general formula for ordering of isoclinic and isochromatic fringes of plane polariscope. On the second, we proposed a novel approach to search the inconsistent area in the wrapped data for overcoming the divergence of celluar automata phase unwrapping. Finally, we overcame the unwrapping problem caused by the singular point of the wrapped data. By this newly developed automatic fringe counting algorithm for photoelasticity, we have successfully and easily got the orders of the isoclinic as well as isochromatic fringes, that is to say, we can obtain the principal stress angle and principal stress difference of the whole stressed sample in an automatic manner.
URI: http://hdl.handle.net/11455/2769
Appears in Collections:機械工程學系所

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