Photoelastic Stress Analysis Of The Automatic Data Acquisition And Image Processing And Elastoplastic Problems For Mixed Solution

As we all know, photoelastic stress analysis is an advance method of structure stress analysis. But the limitation of some factors, such as the experimental material, is one of major challenges in the studying of photoplasticity. The article is trying to find out an approach to resolve small deflection elastic-plastic problem with a photoelastic method. According to this thought, two jobs are finished primarily. On the one hand, using the elastic results which got from experiment of photoelasticity, considering the model theory of elastic-plasticity and the deformation theory of plasticity, the paper propose hybrid methods for elastic-plastic problems. On the other hand, it can find out a new approach through combining present method with image processing.The elastic solution for elastic-plastic problem is based on model theory of elastic-plasticity and deformation theory of plasticity. With the original data which embodies the stress state of complicated structure at elastic phase and is attained by experiment or calculation, according to the similarity theory between elasticity and plasticity and generalized stress-strain material curves, and using new means and new techniques, this method and change the elastic value into plastic value correspondingly. In the programming, this paper adopts structural analysis and optimal design, and applies Visual Basic programming language. It also introduces database to mange the original and calculated data. The operation is convenient and simply. The calculated results can be shown as figures. In the testing, we experiment on a plate with a circle hole (2-dimention) and a ladder axis with arc transiting (3-dimention), and compare the former to the result measured by moire method and the later to an aluminum axis with similarity of geometric structure by electric measure method. The results are closed to these of corresponding references. Sequentially, it is proved that the theory is reasonable and the method is feasible.Linking photoelasticity and computer technique and realizing the image automatic reduction is one of major directions to develop experimental mechanics. It will improve analysis efficiency and experimental precision greatly if putting the photoelastic images gotten from experiment into computer, obtaining the isochromatic and isoclinic data automatically and writing it into database directly. But because of the limitation of time and the difficulty of drawing pure isoclinics from images, the paper has only shown the achievements presently and simulated a disk under diametral compression as foundation on further research. You can look at it in chapter 3.Comparing the calculated results and the theoretical results, it can discover that the error is not out of the permitted range. Then, the present method is efficiency and can be applied to engineering.