Study And Application Of Digital Speckle Correlation Method

Digital speckle correlation method (DSCM), which was developed in the 80,s of last century, is an optical measuring technique. The important meaning of DSCM research is that it possesses many advantages, such as white light source, simple optical arrangements, big measuring range and no requirement of vibration isolation, of which other traditional optical measuring methods are lack. Unfortunately, the existing DSCM is not so perfect to be used in engineering measurement not only on precison but on precessing speed. For example, the displacement and strain measurement accuracy is low due to the influence of noise or the imperfection of the algorithm and the deformation rule and phenomena cannot be displayed. In addition, most researchers use MATLAB or Object-Process language, such as Fortran and C, to programme DSCM. Because most of them are lack of the practical computer experience, those softwares compiled by them are hard to learn, maintain and extend. Due to these causes, their productions are not used by other researchers effectively, which cause a lot of waste of time and efforts. In this paper, some key techniques for DSCM are studied, and a new DSCM software measurement system is developed, which copiled with Visual C++.NET and ANSI C++. The software covers a lot of class libraries.The main achievements of this thesis are listed as following: (1) A new digital image speckle correlation method that based on the BFGS and simulated anneal is developed, which absorbs the adjacent point initial estimate. This new method not only improves calculate speed markedly, but also avoids the possibility of local constringency. (2) The author develops most of the classes with ANSI C++. There have mighty independency between these classes. After a-short-time application of my software and fixing some bugs, now the DSCM software works very well. Other researchers can learn and ameliorate this software easily. For example, a research could only devote his mind to a class if he wants to ameliorate this class, and he only learn the basal function of other class. Additionally, the author compiles GUI with MFC (Microsoft Foundation Class) ported together with Visual C++.Net. On the user interface, the user can choose reciprocal arithmetic. And the software can represent mathematic concept and routine very well so the researcher can focus on the...