造船用鋼材の高応力疲れ試験 (第3報)
1961 年 1961 巻 110 号 p. 317-323
詳細
1961 年 1961 巻 110 号 p. 317-323
In the precee ding reports, the auther have studied about the low-cycle fatigue properties of ship structural steel, by simple rotatary bending tests of round-notched specimens. Measuring the crack depth in its propagating stage by heat tinted method, the rate of crack growth was proved to be proportional to the current crack depth.
In this report, by some theoretical and experimental analysis, the proportional coefficient is explained to be a function of the dimensions of specimen, notch size, and testing procedures, and independent to the materials and applied stress values. Approximately it can be expressed by a power function of the stress amplitude, and the power index is identified by the slope of the σ-N diagram of the specimen.
