Reliability-based assessment of deteriorating ship structures operating in multiple sea loading climates

A holistic approach to risk-based decision on inspection and design of fatigue-sensitive structures

“…S-N method has been widely adopted in designing structures against fatigue, including both deterministic design methods [7] and probabilistic design methods [8]. The fracture mechanics (FM) method has been used to develop probabilistic models to assess fatigue reliability [9][10][11], to update inspection plans [12][13][14][15][16][17], and to develop cost-effective inspection & maintenance plans for existing structures [1,[18][19][20][21]. The studies address almost exclusively either fatigue design issues with little quantitative analysis in operational maintenance or address maintenance issues based on given design plans or existing structures.…”

Reliability-Based Inspection Planning of the Ship Structure Exposed to Fatigue Damages

“…The initial crack size is assumed to follow a normal distribution with mean value of 0.5 mm and standard deviation of 0.05 mm [6]. The natural logarithm of the material parameter C (ln(C)) is treated as normal distribution random variable with a mean value of -29.97 and standard deviation of 0.514 [14] while the material parameter m is assumed to follow a normal distribution with a mean value of 3.0 and standard deviation of 0.15. The correlation coefficient between m and ln(C) is assumed to be -0.9 [15].…”

Fatigue Probability Evaluation Method Based on the Principle of Sample-polymerization

“…在小样本 P-S-N 曲线方面，傅惠民等 [4] 利用异 方差回归理论，基于疲劳寿命服从对数正态分布， 通过对全部寿命数据的统计，获得较高精度的小样 本 P-S-N 曲线。吕箴等 [5] 利用历史数据和现有数据 的融合，通过加权最小二乘法对融合样本进行统计 获得 P-S-N 曲线。也有学者利用 Bayes 理论，结合 先验信息，统计 P-S-N 曲线 [6][7][8][9] 。还有学者利用人工 神经网络分析疲劳寿命分散性，获得 P-S-N 曲 线 [10][11][12] 。近期，出现了样本集聚原理，主要利用一 种摄动寻优技术，通过对全部疲劳寿命试验数据的 融合样本进行统计， 获得小样本的 P-S-N 曲线 [13][14] 。 然而，由于数学计算繁琐或精度及稳定性等原因， 目前还没有能很好满足工程应用的方法。 在疲劳可靠性评估方面，多数是涉及恒幅循环 载荷 [15] 或等效恒幅载荷 [16] ，还有极限载荷分布 [17] 和变幅载荷 [18] 的研究。也有学者利用"应力-强度干 涉模型"进行了载荷多次作用的研究 [19][20] 。但是， 对于疲劳可靠性问题，不仅需要反映损伤演化规律 与载荷历程之间的关系，还须反映它与载荷不确定 性之间的关系 (1)的形式 [13][14] lg lg…”