Two-stage Bayesian system identification using Gaussian discrepancy model

System identification aims at updating the model parameters (e.g., mass, stiffness) associated with the mathematical model of a structure based on measured structural response. In this process, a two-stage approach is commonly adopted. In Stage I, modal parameters including natural frequencies and m...

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Main Authors: Zhang, Feng-Liang, Au, Siu-Kui, Ni, Yan-Chun
Other Authors: School of Civil and Environmental Engineering
Format: Journal Article
Language:English
Published: 2020
Subjects:
Online Access:https://hdl.handle.net/10356/143231
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author Zhang, Feng-Liang
Au, Siu-Kui
Ni, Yan-Chun
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Zhang, Feng-Liang
Au, Siu-Kui
Ni, Yan-Chun
author_sort Zhang, Feng-Liang
collection NTU
description System identification aims at updating the model parameters (e.g., mass, stiffness) associated with the mathematical model of a structure based on measured structural response. In this process, a two-stage approach is commonly adopted. In Stage I, modal parameters including natural frequencies and mode shapes are identified. In Stage II, the modal parameters are used to update structural parameters such as those related to stiffness, mass and boundary conditions. A recent Bayesian formulation allows the identification results in the first stage to be incorporated in the second stage directly via Bayes' rule without using a heuristic model (often based on classical statistics) that transfers the information from Stage I to II. This opens up opportunities for explicitly accounting for modeling error in the structural model (Stage II) through the conditional distribution of modal parameters given structural model parameters. Following this approach, this paper investigates a methodology where the modeling error between the two stages is incorporated with Gaussian distributions whose statistical parameters are also updated with available data. Leveraging on special mathematical structure induced by the model, computational issues are resolved and an analytical investigation is performed that yields insights on the role of modeling error and whether its statistics can be distinguished from those of identification uncertainty (defined for given structural model). The proposed methodology is verified using synthetic data and applied to a laboratory-scale structure.
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spelling ntu-10356/1432312020-08-14T03:19:32Z Two-stage Bayesian system identification using Gaussian discrepancy model Zhang, Feng-Liang Au, Siu-Kui Ni, Yan-Chun School of Civil and Environmental Engineering Institute of Catastrophe Risk Management (ICRM) Engineering::Civil engineering System Identification Two-stage Formulation System identification aims at updating the model parameters (e.g., mass, stiffness) associated with the mathematical model of a structure based on measured structural response. In this process, a two-stage approach is commonly adopted. In Stage I, modal parameters including natural frequencies and mode shapes are identified. In Stage II, the modal parameters are used to update structural parameters such as those related to stiffness, mass and boundary conditions. A recent Bayesian formulation allows the identification results in the first stage to be incorporated in the second stage directly via Bayes' rule without using a heuristic model (often based on classical statistics) that transfers the information from Stage I to II. This opens up opportunities for explicitly accounting for modeling error in the structural model (Stage II) through the conditional distribution of modal parameters given structural model parameters. Following this approach, this paper investigates a methodology where the modeling error between the two stages is incorporated with Gaussian distributions whose statistical parameters are also updated with available data. Leveraging on special mathematical structure induced by the model, computational issues are resolved and an analytical investigation is performed that yields insights on the role of modeling error and whether its statistics can be distinguished from those of identification uncertainty (defined for given structural model). The proposed methodology is verified using synthetic data and applied to a laboratory-scale structure. Nanyang Technological University Accepted version This paper is funded by the National Natural Science Foundation of China (Grant No.: 51878484; F.-L.Z.), Natural Science Foundation of Shenzhen (Grant No.: JCYJ20190806143618723; F.-L.Z.), a start-up grant SUG/4 (S.-K.A.) from Nanyang Technological University, Singapore, and Scientific Research Fund of Institute of Engineering Mechanics, China Earthquake Administration (Grant No.: 2019 EEEVL0401; Y.-C.N.). The financial support is gratefully acknowledged. 2020-08-14T03:19:32Z 2020-08-14T03:19:32Z 2020 Journal Article Zhang, F.-L., Au, S.-K., & Ni, Y.-C. (2020). Two-stage Bayesian system identification using Gaussian discrepancy. Structural Health Monitoring. doi: 10.1177/1475921720933523 1741-3168 https://hdl.handle.net/10356/143231 10.1177/1475921720933523 en 51878484 JCYJ20190806143618723 M4082398 2019 EEEVL0401 Structural Health Monitoring © 2020 SAGE Publications. All rights reserved. This paper was published in Structural Health Monitoring and is made available with permission of SAGE Publications. application/pdf
spellingShingle Engineering::Civil engineering
System Identification
Two-stage Formulation
Zhang, Feng-Liang
Au, Siu-Kui
Ni, Yan-Chun
Two-stage Bayesian system identification using Gaussian discrepancy model
title Two-stage Bayesian system identification using Gaussian discrepancy model
title_full Two-stage Bayesian system identification using Gaussian discrepancy model
title_fullStr Two-stage Bayesian system identification using Gaussian discrepancy model
title_full_unstemmed Two-stage Bayesian system identification using Gaussian discrepancy model
title_short Two-stage Bayesian system identification using Gaussian discrepancy model
title_sort two stage bayesian system identification using gaussian discrepancy model
topic Engineering::Civil engineering
System Identification
Two-stage Formulation
url https://hdl.handle.net/10356/143231
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