The Research On Displacement And Deformation Measurement Methods Based On Digital Image Processing

Composite materials’ mechanical properties and bearing structure in complicated environment are important factor when they are used in the engineering project, they are also an important factor restricting the development of a variety of new technology. The knowledge of materials’ mechanical properties and bearing structure is not perfect, we have to evaluate its performance by experiment. Displacement and strain measurement is an important method to evaluate materials’ mechanical properties and bearing structure. The method for measuring the displacement and strain is mainly divided into contact measurement method and non-contact measurement method, the contact measurement method is easily affected by complex environment and its error may be large, so no-contact measurement method has more advantages under complex environment. Typical non-contact measuring method at present is the optical measurement method, including holographic interferometry, the photoelastic method, the moire method, CGS method and digital image correlation method, but in these methods,the measuring light path is complex, the measurement environment is demanding and easily affected by complex environment, thus the measurement accuracy is decreased and the stability is poor. We need some displacement and strain measurement method which can be used in complex environment, this is one of the important tasks in current experiment mechanics researches.In order to solve the above problem, this paper introduces the feature recognition technology to measure the displacement and strain. This paper presents and improves SIFT method based on feature recognition to measure the displacement and strain according to the actual situation.Through foundation and high temperature experiment, this method is proved having good accuracy and stability, it is also used to measure displacement and strain in complex environment. In order to solve the problem in structural displacement measurement, this paper puts forward the structure measurement method based on the image edge characteristics. This method is implement by canny edge detection algorithm and hough transform algorithm in this paper,also,it is proved having good precision and strong stability, fully applicable to measure structure in complex environment.Measuring displacement and strain in complex environments by image processing technology is proved having good precision and strong stability by experiment and theory analysis in this paper. This technique can also be extended similar in many research fields and it is a scalable non-contact measurement method. This paper designs and achieves software to measure displacement and strain based on image processing and introduces how it was designed and how to use it.