パンタグラフ枠にはめ込まれた中空正方形板の応力集中係数・応力拡大係数

抄録

The stress concentration factors on the edges of square plates with rounded square holes and the stress intensity factors for the corner edge cracks of square plates with square holes are evaluated by photoelastic experiment. The epoxy resin models of hollow square plates are fitted into a pantograph frame, and the models are loaded by tensile loads in the diagonal direction of the frame.
Numbers of the isochromatic fringe patterns taken by means of a CCD camera are recorded in a magneto optical disk, and transformed into the thinning images of them by utilizing an image processing analyzer. From the thinning images obtained, the required data are collected to evaluate the stress concentration factors and the stress intensity factors.
The local stress concentration factors are shown in the diagrams for the local muximum stress at the some points on the inner and outer edges of the hollow square plate, and finally a diagram of the stress concentration factor depended on the radius of curvature of the corners and the wall thickness are obtained from their local stress concentration factors. Moreover, and the stress intensity factors for the corner edge cracks are given as diagrams representing the behavior depended on the crack depth and the wall thickness.