フィレット部で支持され引張荷重を受けるすみクラックT形平板の応力拡大係数

抄録

The photoelastic experiment is conducted in order to evaluate the mixed-mode stress intensity factors for corner cracks of T-shaped plate supported along the lower edges of fillets under tensile load. The epoxy resin models with various height of fillet are prepared, and the corner cracks are machined with the diamond disc saw to give the systematically varied depth and angle.
A large number of the isochromatic fringe patterns taken by means of a CCD camera are recorded in the magneto optical disk, and are transformed into the thinning images of them by utilizing the image processing analyzer. From the thinning images obtained, the required data are collected to evaluate the stress intensity factors.
The behavior of mixed-mode stress intensity factors depending on crack depth, crack angle and height of fillet is analyzed and summarized in lots of diagrams. Especially, it is made clear that the fracture of T-shaped plate with thin fillets is caused by the deformation of mode I which is superior to mode II in its magnitude. Moreover, the consideration about the looped isochromatic fringe patterns is described, and the result of the fracture experiment on T-shaped plate which was made with FC10, S55C and acrylic resin is shown in order to confirm that of the photoelastic experiment.