基于未知风荷载作用下拉索振动位移的拉索MR阻尼器失效破坏的原位识别方法  

In-situ identification of cable MR damper failure based on cable vibration displacements under unknown wind loads

作　　者：雷鹰[1] 杨雄骏 朱宏平[2] 沈文爱 Lei Ying;Yang Xiongjun;Zhu Hongping;Shen Wenai(Xiamen University,Xiamen 361005,China;Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]厦门大学,福建厦门361005 [2]华中科技大学,湖北武汉430074

出　　处：《土木工程学报》2024年第6期180-189,共10页China Civil Engineering Journal

基　　金：国家自然科学基金重点项目(51838006)。

摘　　要：MR阻尼器在长期服役过程中可能由于各种因素导致阻尼器失效破坏。现有的对MR阻尼器的性能识别多为离线方法,需将阻尼器从斜拉索上拆卸下来后进行人工检测。该文提出一种基于斜拉索在未知风荷载作用下振动位移,对在役失效无模型的MR阻尼器作用力进行原位在线识别的方法。首先,建立模态坐标下斜拉索-阻尼器系统运动方程及观测方程,并进行模态截断以减少未知变量的数量。然后,将模态风荷载建模为随机游走过程并加入系统的增广状态中,并视MR阻尼器的作用力视为作用在斜拉索上的‘附加未知输入’,采用最近提出的无直接反馈的平滑最小方差无偏Bayesian滤波,对结构增广状态和MR阻尼器作用力进行识别。通过识别数值模拟的MR阻尼器三种典型的失效破坏模式,验证所提方法的有效性。Magnetorheological(MR) dampers may be damaged due to various factors during their long-term service.Most of the existing identification methods for MR dampers are offline methods,and when applying them,the damper needs to be removed from the stay cable for manual inspection.In this work,an online field method is proposed to identify the model-free forces of in-service MR dampers based on the vibration displacement of the stay cable under unknown wind load.First,the equations of motion and observations of the cable-damper system in the modal coordinate are established,and the modal truncation is performed to reduce the number of unknown variables.Subsequently,the modal wind loads are modeled as random walk processes which are added to the augmented state of the system,and the nonlinear MR damper force is considered as “additional unknown input” to the cable.Under partial observations of cable vibration displacements,smoothing minimum variance unbiased filter without direct feedthrough is adopted herein to identify the augmented state and MR damper force.Finally,based on three typical failure modes of MR damper identified in numerical simulations,the effectiveness of the proposed method can be verified.

关 键 词：斜拉索减振 MR阻尼器失效 未知风荷载 随机游走过程 平滑最小方差无偏滤波 

分 类 号：TU18[建筑科学—建筑理论]