疲労き裂伝播速度に関する研究 : 第3報 : 疲労き裂伝播速度の計算法

概要

論文の詳細を見る
In our previous papers, assuming that fatigue crack propagation is continuous fatigue crack initiation at the crack tip, a model for fatigue crack propagation was presented. And for this model, an equation for calculating the crack propagation rate was derived in terms of stress intensity factor, effective stress range ratio and material properties such as Young's modulus, yield strength in strain cycling, strain-hardening exponent in strain cycling, Manson-Coffin's exponent, etc. In this report, effect of fatigue crack closure phenomenon on the crack propagation rate is investigated experimentally, and relation between effective stress range ratio U and Stress ratio R is given for mild steel. Further more, effect of the material constants on the propagation rate is also studied based on the above equation. Experimental values of crack propagation rate on various stress ratio obtained by authors and several investigators are compared with calculated ones, and fairly good agreement between them was found.
社団法人日本船舶海洋工学会の論文