建構立體數位影像相關法之基礎理論並應用於結構靜態與動態三維變形精密量測

Abstract

數位影像相關法(DIC)是一種非接觸全場位移量測光學方法，由於其方便性與實用性高，目前在實驗力學領域上是最常被學者研究及應用的量測技術之一。本文主要開發高精度的影像搜尋演算法與具有人機介面的二維數位影像相關法(2D DIC)及立體數位影像相關法(Stereo DIC)程式系統，並分別應用於機械工程(動態量測)、土木工程(靜態量測)與生物力學的領域上。文中首先提出投影形狀函數搭配反向合成高斯牛頓法(IC-GN method)，接著測試與探討一階、二階與投影形狀函數搭配IC-GN method應用於二維搜尋與立體搜尋在各種不同的條件與情況下的量測精度，並介紹自行開發的具有人機介面之2D DIC程式，稱為2D GSPIC，使用SEM DIC Challenge提供測試影像驗證其量測精度，最後介紹自行開發的具有人機介面之Stereo DIC程式，稱為Stereo GSPIC，參考不同形狀函數在不同的情況下的量測精度，決定Stereo GSPIC在二維搜尋與立體搜尋的追蹤策略。 動態量測上，必須使用高速攝影機進行拍攝量測，本文採用一組分光鏡將兩個不同視角影像同時入射到一台高速攝影機，此種架設方法可以同時解決左右影像同步性問題以及雙高速攝影機高成本架設問題，並提出使用帶通濾波法對結構全場暫態量測結果進行濾波得到模態形狀，最後使用一台高速攝影機Stereo DIC系統量測懸臂薄板共振頻率、共振模態以及受到動力負載後的全場暫態面外位移，並與光纖位移計(FS)、理論解析與有限元素法(FEM)模擬結果進行比對。在準靜態量測上，本文分別使用2D DIC與Stereo DIC技術應用於核電廠圍阻體結構受反覆負載下的實驗，首先將Stereo DIC與2D DIC同時量測圍阻體變形結果做比較與驗證，確認Stereo DIC與2D DIC量測的正確性後，利用Stereo DIC量測圍阻體的三維變形與垂直、水平方向應變，從應變較大區域呈現明顯的裂縫產生與擴展，進而量測該區域隨著時間變化的開放裂縫寬度，最後使用2D DIC技術量測圍阻體側面剪切裂縫的位置與滑移量。最後本文針對心臟醫學影像提出一種不規則形狀樣板子集合方法，採用二階變形函數近似心臟肌肉內壁的複雜變形，追蹤心臟肌肉內壁隨著時間的變化，計算內壁面積隨著時間的變化率，使用心臟超音波影像及心臟核磁共振影像進行測試，並與市售軟體WMT及人工分析方式驗證。

Digital image correlation (DIC) is a convenient and practical optical metrology for non-contacting and full-field deformation measurement of structures, which has been commonly accepted and widely used in the field of experimental mechanics. This thesis mainly contribute to develop high-accuracy sub-pixel image matching algorithm in home-made 2D DIC and Stereo DIC software, and apply to mechanical engineering (dynamic measurement), civil engineering (static measurement) and biomechanics. Firstly, an inverse compositional Gauss-Newton (IC-GN) algorithm with projective shape function is proposed, and compares IC-GN method with first-order and second-order shape function measurement accuracy in different deformation conditions of 2D and stereo matching. Measurement accuracy of the 2D DIC software is verified by SEM DIC Challenge testing images. The strategy of 2D and stereo matching of stereo DIC software is presented, based on different features of shape functions. Secondly, a Stereo DIC system include a high-speed camera and a set of mirrors is applied to dynamic measurement. This method can remove the synchronization and solve the high-costing problem with two high-speed camera system. In addition, a new technique is proposed to find the mode shape of structures by band-pass-filter method. The resonance frequency, resonance mode shape and full-field transient displacement response of a cantilever thin plate are measured by single high-camera Stereo DIC system. The Fotonic sensor (FS) displacement measurement instrument, theory and finite element method (FEM) are used to verify the measurement result of the Stereo DIC technique. Thirdly, in static measurement, 2D DIC and Stereo DIC software are applied to the cyclic tests of cylindrical concrete containment structure in nuclear power plant. The three-dimensional deformation, vertical strain, horizontal strain, open crack width, position and slide of shear crack of RC containment structure are measured and are discussed in detail. Finally, an irregular template subset and second-order shape function of IC-GN method is applied to cardiac medical image tracking. This method is used to analyze cardiac ultrasound images and cardiac magnetic resonance images. The result is compared with the measurement result of the commercial software and artificial analysis.