TY - JOUR

T1 - A full-probabilistic cloud analysis for structural seismic fragility via decoupled M-PDEM

AU - Lyu, Meng Ze

AU - Feng, De Cheng

AU - Cao, Xu Yang

AU - Beer, Michael

N1 - Funding Information: Financial supports from the Project of National Key Research and Development Program of China (Grant No. 2022YFC3803004), the National Natural Science Foundation of China (Grant No. 12302037), China Postdoctoral Science Foundation (Grant No. 2023M732669), Shanghai Post‐Doctoral Excellence Program (Grant No. 2022558), and the Natural Science Foundation of Jiangsu Province (Grant No. BK20220984) are highly appreciated. Prof. Jian‐Bing Chen from Tongji University is gratefully appreciated for his constructive comments and encouragement.

PY - 2024/2/14

Y1 - 2024/2/14

N2 - Performance-based earthquake engineering (PBEE) is essential for ensuring engineering safety. Conducting seismic fragility analysis within this framework is imperative. Existing methods for seismic fragility analysis often rely heavily on double loop reanalysis and empirical data fitting, leading to challenges in obtaining high-precision results with a limited number of representative structural analysis instances. In this context, a new methodology for seismic fragility based on a full-probabilistic cloud analysis is proposed via the decoupled multi-probability density evolution method (M-PDEM). In the proposed method, the assumption of a log-normal distribution is not required. According to the random event description of the principle of preservation of probability, the transient probability density functions (PDFs) of intensity measure (IM) and engineering demand parameter (EDP), as key response quantities of the seismic-structural system, are governed by one-dimensional Li-Chen equations, where the physics-driven forces are determined by representative analysis data of the stochastic dynamic system. By generating ground motions based on representative points of basic random variables and performing structural dynamic analysis, the decoupled M-PDEM is employed to solve the one-dimensional Li-Chen equations. This yields the joint PDF of IM and EDP, as well as the conditional PDF of EDP given IM, resulting in seismic fragility analysis outcomes. The numerical implementation procedure is elaborated in detail, and validation is performed using a six-story nonlinear reinforced concrete (RC) frame subjected to non-stationary stochastic ground motions. Comparative analysis against Monte Carlo simulation (MCS) and traditional cloud analysis based on least squares regression (LSR) reveals that the proposed method achieves higher computational precision at comparable structural analysis costs. By directly solving the physics-driven Li-Chen equations, the method provides the full-probabilistic joint information of IM and EDP required for cloud analysis, surpassing the accuracy achieved by traditional methods based on statistical moment fitting and empirical distribution assumptions.

AB - Performance-based earthquake engineering (PBEE) is essential for ensuring engineering safety. Conducting seismic fragility analysis within this framework is imperative. Existing methods for seismic fragility analysis often rely heavily on double loop reanalysis and empirical data fitting, leading to challenges in obtaining high-precision results with a limited number of representative structural analysis instances. In this context, a new methodology for seismic fragility based on a full-probabilistic cloud analysis is proposed via the decoupled multi-probability density evolution method (M-PDEM). In the proposed method, the assumption of a log-normal distribution is not required. According to the random event description of the principle of preservation of probability, the transient probability density functions (PDFs) of intensity measure (IM) and engineering demand parameter (EDP), as key response quantities of the seismic-structural system, are governed by one-dimensional Li-Chen equations, where the physics-driven forces are determined by representative analysis data of the stochastic dynamic system. By generating ground motions based on representative points of basic random variables and performing structural dynamic analysis, the decoupled M-PDEM is employed to solve the one-dimensional Li-Chen equations. This yields the joint PDF of IM and EDP, as well as the conditional PDF of EDP given IM, resulting in seismic fragility analysis outcomes. The numerical implementation procedure is elaborated in detail, and validation is performed using a six-story nonlinear reinforced concrete (RC) frame subjected to non-stationary stochastic ground motions. Comparative analysis against Monte Carlo simulation (MCS) and traditional cloud analysis based on least squares regression (LSR) reveals that the proposed method achieves higher computational precision at comparable structural analysis costs. By directly solving the physics-driven Li-Chen equations, the method provides the full-probabilistic joint information of IM and EDP required for cloud analysis, surpassing the accuracy achieved by traditional methods based on statistical moment fitting and empirical distribution assumptions.

KW - decoupled multi-probability density evolution method (M-PDEM)

KW - full-probabilistic cloud analysis

KW - Li-Chen equation

KW - performance-based earthquake engineering (PBEE)

KW - seismic fragility

UR - http://www.scopus.com/inward/record.url?scp=85185459116&partnerID=8YFLogxK

U2 - 10.1002/eqe.4093

DO - 10.1002/eqe.4093

M3 - Article

AN - SCOPUS:85185459116

VL - 53

SP - 1863

EP - 1881

JO - Earthquake Engineering and Structural Dynamics

JF - Earthquake Engineering and Structural Dynamics

SN - 0098-8847

IS - 5

ER -