抄録
This paper shows a simple method of calculating the stress intensity factor of a through crack filled with viscous lubricating oil. A center crack specimen is assumed under plane strain conditions. For the lubricating oil, it is assumed that the pressure rise due to the squeeze effect follows the Reynolds equation. The full Reynolds equation is approximated by a one-dimensional equation in the same way as is done for sliding bearings. As the crack is closing, the squeeze effect produces pressure, which tends to open the crack. This effect varies considerably with the thickness of the specimen. For a thin specimen, the squeeze effect on the stress intensity factor can be estimated by the infinitely short approximation, where the pressure distribution is assumed to be parabolic in the thickness direction. For a thick specimen, on the other hand, the infinitely long approximation is applied, where the pressure is assumed to be constant in the thickness direction.
