Bayesian spectral density approach for identification of bridge section's flutter derivatives operated in turbulent flow. (1st May 2022)

• Record Type: Journal Article
• Authors: Chu, Xiaolei; Cui, Wei; Liu, Peng; Zhao, Lin; Ge, Yaojun
• Is Part Of: Mechanical systems and signal processing. Volume 170(2022)
• Publication Date: 2022-05-01
• Subjects: Bayesian spectral density approach -- Flutter derivatives -- Complex Wishart distribution -- Wind tunnel test -- Bayesian inference -- Markov chain Monte-Carlo sampling; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2021.108782
• Languages: English
• ISSNs: 0888-3270

Abstract

Abstract: This study presents a Bayesian spectral density approach for identification of flutter derivatives of bridge sections utilizing buffeting displacement responses, where the wind tunnel test is conducted in turbulent flow. Different from traditional time-domain approaches (e.g., least square method and stochastic subspace identification), the newly-proposed approach is operated in frequency domain. Based on the affine invariant ensemble sampler algorithm, Markov chain Monte-Carlo sampling is employed to accomplish the Bayesian inference. The probability density function of flutter derivatives is modeled based on complex Wishart distribution, where probability serves as the measure. By the Bayesian spectral density approach, the most probable values and corresponding posterior distributions (determined by conditions of measured signals) of each flutter derivative can be obtained at the same time. Firstly, numerical simulations are conducted and the identified results are accurate. Secondly, thin plate model, flutter derivatives of which have theoretical solutions, is chosen to be tested in turbulent flow for the sake of verification. The identified results of thin plate model are consistent with the theoretical solutions. Thirdly, the center-slotted girder model, which is widely-utilized long-span bridge sections in current engineering practice, is employed to investigate the applicability of the proposed approach on a general bridge section. For the center-slotted girder model, the flutter derivatives are also extracted by least square method in uniform flow to cross validate the newly-proposed approach. The identified results by two different approaches are compatible. Highlights: Flutter derivatives is identified in frequency domain and in turbulent flow. Flutter derivatives are probabilistically modeled by complex Wishart distribution. Markov chain Monte-Carlo sampling is employed for identification. Applicability of the proposed approach is verified by wind tunnel tests.