Development of stress analysis method by hybrid system combining photoelasticity with numerical method

1.高速有限元分析系统的研制将光弹性图像处理系统与高速有限元分析系统相结合，开发了高性能应力分析系统。由于该系统是在16位微机上开发的，可以有效地在线实时执行程序。光弹性分析视频系统的研制利用微机和图像帧存储器开发了光弹性条纹图像处理系统。用c语言开发了平滑、滤波等基本的图像处理软件。会话混合系统的开发；我们开发了对话式混合系统，可以将有限元分析结果与光弹性实验结果进行比较。该系统通过图像处理程序识别试样的边界形状，并将其转换为坐标数据。然后，生成满足边界条件的有限元网格，并进行有限元分析。根据有限元计算结果计算等色条纹位置，并将其叠加到光弹性图像显示器上。这两种结果的差异很容易被检测出来，并反馈到计算中。发达体系对复杂结构的应力分析利用开发的图像处理系统，对接触问题和裂纹体进行了应力分析。作为一个接触问题，对两个不同尺寸的圆板相互施加压力，利用所开发的系统对应力分布进行了分析。我们无法找到容易得到最终答案的好方法，我们证实了混合系统可以很容易地检测出两种方法结果的差异。针对裂纹问题，我们开发了一种新的方法，可以方便地从图像数据中分析I型应力强度因子。将计算结果与理论计算结果进行了比较，得到了满意的结果。

1.Development of high speed F.E.M system;We developed high performance stress analysis system by combining image processing system for photoelasticity with high speed F.E.M system. As the F.E.M system was developed on 16-bit micro-computer, on-line real time procedure can be executed efficiently.2.Development of video system for photoelastic analysis;We developed image processing system for photoelastic fringe by using micro-computer and image frame memory. Basic image processing software such as smoothing, filtering were also developed by using C-language.3.Development of conversational hybrid system;We developed conversational hybrid system, which can compare the result of FEM analysis with the experimental results of photoelasticity. In this system, boundary shape of the specimen is acknowledged by the image processing procedure and is converted to the coordinate data. Then, finite element mesh, which satisfy those boundary condition, are generated and FEM analvsis is executed. The isochromatic fringe positions are calculated from the FEM result and those are superimposed on the image moritor of photoelasticity. The difference of both results are detected easily and are feed-backed to the calculation.4.Stress analysis of complicated structure by developed system;By using the developed image processing system, we conducted stress analysis for contact problem and cracked body. As a contact problem, two different size circle plates are pressed on each other and the stress distribution is analysed by the developed system. We could not find the good method to attain the final answer easily, we confirmed that the difference of the result of two methods are detected easily by the hybrid system. For the crack problem, we developed new method to analyse the mode I stress intensity factor from the image data easily. The results are compared with the theoretical one and satisfactory results are obtained.