CAJ | 학술논문

针对斜拉桥静力体系可靠度分析中隐式功能函数重构和繁杂失效路径的特点，提出了一种基于更新支持向量的体系可靠度分析方法，将传统的用于构件可靠度分析的支持向量机（SVM ）改进并应用于斜拉桥体系可靠度分析。该方法主要有4个步骤：首先通过构件的敏感分析识别斜拉桥的主要失效路径；其次采用最小二乘支持向量机（LS‐SVM ）对斜拉桥的隐式功能函数进行重构，并通过Monte‐Carlo抽样得出构件的可靠指标；然后根据已经更新的有限元模型对支持向量进行更新，得出相关构件失效后的剩余构件的条件可靠指标；最后由结构体系的失效树和串并联关系得出斜拉桥的体系可靠度。主跨为420 m的混凝土斜拉桥算例分析表明了上述算法的有效性和实用性，同时也获得了该斜拉桥的主要失效路径并识别了影响其体系可靠度的主要构件。
침대사랍교정력체계가고도분석중은식공능함수중구화번잡실효로경적특점，제출료일충기우경신지지향량적체계가고도분석방법，장전통적용우구건가고도분석적지지향량궤（SVM ）개진병응용우사랍교체계가고도분석。해방법주요유4개보취：수선통과구건적민감분석식별사랍교적주요실효로경；기차채용최소이승지지향량궤（LS‐SVM ）대사랍교적은식공능함수진행중구，병통과Monte‐Carlo추양득출구건적가고지표；연후근거이경경신적유한원모형대지지향량진행경신，득출상관구건실효후적잉여구건적조건가고지표；최후유결구체계적실효수화천병련관계득출사랍교적체계가고도。주과위420 m적혼응토사랍교산례분석표명료상술산법적유효성화실용성，동시야획득료해사랍교적주요실효로경병식별료영향기체계가고도적주요구건。
A new system reliability assessment method is proposed based on updating support vector method ,considering the characteristic of cable‐stayed bridges with explicit performance functions and multiple failure modes .The traditional Support Vector Machine (SVM ) is developed and applied to sys‐tem reliability analysis of cable‐stayed bridges .T here are four main steps in this algorithm :firstly ,the main failure sequences should be rectified according to the sensitivity analysis of components ;secondly , Least Squares Support Vector Machine (LS‐SVM ) is used to approximate the structural responses ,and then reliability indices of components are obtained using Monte‐Carlo simulation method .Thirdly ,the support vectors in LS‐SVM model are updated on the basis of updated finite element models ,and then the conditional reliability indices of the rest components is calculated based on the updated support vector model;finally ,the failure tree of structural system and series parallel method are used to estimate the system reliability index .The numerical analysis of a concrete cable‐stayed bridge with 420m span has shown the effectiveness and applicability of the proposed algorithm .At the same time ,the main failure sequences and the main failure components of the concrete bridge are given .