基于多指标融合的斜拉索可靠性评估

Reliability Evaluation of Stay-cables based on Multiple Indexes Fusion

在斜拉桥服役过程中,斜拉索属于易损构件,控制着全桥的性能优劣,因此有必要通过多种指标对其进行可靠度评估。提出一种基于多指标融合的斜拉索可靠性评估方法,从安全性和耐久性两方面入手,分别以运营状态下拉索应力、汽车荷载应力幅、拉索基频、拉索服役时间及PE护套损伤情况为判别指标,利用模糊数学的方法进行基于客观限值指标模糊等级的划分,确定指标隶属度向量并汇总形成隶属度矩阵,随后通过层次分析法确定指标初始权值向量。最后,将隶属度矩阵和指标初始向量进行模糊运算,通过最大隶属度原则完成斜拉索可靠性的最终评估。经工程实例验证,本方法能有效综合各指标的客观限值与专家主观经验,较为准确地评估斜拉索的可靠性,评估结果与现行规范适应性较好。

During the service of cable-stayed bridge,stay cables are vulnerable components and thus they control the performance of the whole bridge.Therefore,it is necessary to evaluate its reliability through various indexes.A reliability evaluation method based on multiple index fusion is proposed in this paper.From the safety and durability,the method uses the cable maximum stress,the stress amplitude of the automobile load,the cable basic frequency,the damage of the PE sheath and the service time of the cable are taken as criterions.The Fuzzy Comprehensive Evaluation Method is used to classify the fuzzy grade of the index which is based on objective limitation,the membership degree vector of the index is determined and aggregated into a membership matrix.Then the initial weight vector of the index is determined by AHP.Finally,the membership matrix and the initial index vector are brought into the fuzzy operation,and the final evaluation of reliability is completed by the maximum membership degree principle.This method is verified by engineering practice,and it proves that this method can effectively integrate the objective limit of each index and the subjective experience of experts,and evaluate the reliability of stay cables more accurately.The evaluation result is in good accordance with the current standard.