1993 年 13 巻 1-2 号 p. 29-33
In estimating the strength of materials, it is widely recognized that the stress intensity factors in the vicinity of the crack tip are useful for quantitative explanation of the destruction. Many cracks in construction materials are three-dimensional. Analysis of the stress intensity factors of materials with three-dimensional cracks are therefore of great importance. In thispaper, the stress intensity factors are determined photoelastically with a thick cylinder having a crack in the direction of the circumference or axis on the inner surface being loaded by internal pressure. In the experiments, by using the stress freezing method, inner pressure is loaded at every depth of the crack. The stress patterns at the tip are observed and the fringe orders are determined. The experimental results are analyzed and compared with conventional results reported in the past.