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

1986 Fiscal Year Final Research Report Summary

• Project/Area Number: 60460079
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 材料力学
• Research Institution: University of Tokyo
• Principal Investigator: OKAMURA Hiroyuki University of Tokyo, Faculty of Engineering, 工学部, 教授 (00010679)
• Co-Investigator(Kenkyū-buntansha): SAKAI Shinsuke University of Tokyo, Faculty of Engineering, 工学部, 助教授 (80134469)
• Project Period (FY): 1985 – 1986
• Keywords: Experimental stress analysis / Photoelasticity / Micor-computer / マイクロコンピューター / 画像処理 / ハイブリッドシステム

Research Abstract

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.