舰船复合材料层合板结构疲劳可靠性分析方法初探

Preliminary exploration on fatigue reliability method of composite lamina structures in warship

首先,提出了基于应力-强度干涉模型的舰用复合材料结构疲劳可靠性分析方法,即以可靠度指标对舰艇复合材料结构的正常使用安全性加以评价,并将复合材料结构正常使用安全性问题转换为结构在疲劳和环境载荷作用下的损伤与性能退化机理研究以及可靠度计算问题;然后,基于复合材料力学性能的离散特性,进一步探讨了常规安全系数与可靠度的联系;最后,通过算例给出了在已知结构工作应力分布特征和材料疲劳强度特性条件下,如何求解指定服役期间复合材料结构疲劳可靠度的计算方法和计算流程,并对照给出了相应的安全系数,计算得出疲劳可靠度R为0.933。

Firstly, the method of analyzing composite structure fatigue reliability of warship based on stress-intensity interference model is proposed, which suggests taking reliability as the evaluation in- dex of the safety of the normal use of the composite structure, and translates the normal use of com- posite structure safety issues into reliability calculation and mechanism research of damage and degra- dation of structure under mechanic fatigue and aging environment. And then based on the discrete characteristics of the mechanical performance of the composite materials, and for easy understanding the model at the same time, a further discussion about the relation between conventional safety factor and reliability calculation is made. Finally, the method and process of how to calculate the fatigue reli- ability of a composite structure and the corresponding safety coefficients are given by an example, and it is worked out that the fatigue reliability R is 0.93 under the condition of knowing both structure working stress distribution characteristic and material fatigue strength at a given time.