変動荷重下のき裂伝播に関する研究

抄録

To estimate the crack propagation under random loading more accurately, crack propagation model which takes into consideration the retardation effect in crack propagation is proposed and experiments for verification of this model were carried out. This model is composed of the assumptions as follows : (1) The area in which retardation effect occurs is decided by plastic zone at crack tip. (2) The crack propagation rate (dl)/(dN) at the retardation area is given by (dl)/(dN) = C'・Δ K^m' C' = C・ΔK^<m-m'>_<lm> where C and m are material constants, Δ K is range of K value, m' is material constant at the retardation area and ΔK_<lm> is ΔK value which decides the crack propagation hehavior at the retardation area. Numerical simulation tests using this model showed good agreement with results of crack propagation tests for SM58Q specimen under quasi-random loading tests.