不可检结构可靠性分析

Fatigue Reliability Analysis of Uninspectable Structure

航空器中总存在有不可检测结构，这些结构在使用中，无法进行检测，一般也不进行维修．本文给出了这种不可检结构的可靠性分析模型。

Chinese engineers are now quite interested in the model of fatigue reliability a-nalySis ofuninspectable portions of aircraft structure. We now present our preliminary results on oneaSpect of this important problem.Our model taxes into consideration the following random factors: initial life of crack,propagation life of crack, distribution of applied loading, distribution of fracture toughness,and variation of residual strength. For convenience of engineering application, the model isbased on eq. (1), the propagation rate of fatigue craek proposed by Yang et al[3]. Eq.(10), the distribution of the stress of harzard position due to gust loading proposed by Eggwertz [4], is adopted by us. Now harzard rate H (t), damage probability Pf(t) and reliability ps(t) at time t can be computed with eqs. (14), (15) and (16) respectively.We take, as numerical example, the reliability analysis of a tension apecimen with central crack under spectrum loading. Its harzard rate H (t) and damade probability Pf (t) areshown in Figs. 1 and 2 respectively.