TY - JOUR
T1 - Conditionally simulating nonstationary typhoon winds with time-varying coherences for long-span bridges
AU - Huang, Zifeng
AU - Xu, You Lin
AU - Zhan, Sheng
N1 - Funding Information:
The works described in this paper are financially supported by the Ministry of Science and Technology of China through the National Key R&D Program (Project No. 2019YFB1600700 ) and The Hong Kong Polytechnic University through a special grant ( PolyU 4-ZVM9 ), to which the authors are most grateful. Any opinions and conclusions presented in this paper are entirely those of the authors.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/5
Y1 - 2021/5
N2 - Typhoon winds near its external eye wall are not only strong but also nonstationary with time-varying coherences. This study proposes a conditional simulation method for multivariate nonstationary typhoon winds with time-varying coherences for long-span bridges. The Kriging method for conditional simulation and the time-varying wind spectrum and coherence are first introduced. The decomposition of the time-varying spectrum matrix is then discussed in order to obtain the time-varying correlation functions. It is found that the conventional Cholesky decomposition and the proper orthogonal decomposition (POD) are not suitable and only the square root decomposition (SRD) is appropriate for the decomposition of the spectrum matrix with time-varying coherences. Based on the field-measured nonstationary typhoon wind time histories and the time-varying spectrum and coherence models established for the Stonecutters cable-stayed bridge during Typhoon Hato, the proposed conditional simulation method is finally applied to the bridge and validated by comparing the simulated typhoon wind time histories with the measured ones as well as the unconditional simulation results. The comparative results demonstrate that the conditionally simulated wind time histories are similar to the measured ones and that the proposed conditional simulation method can be used to provide a better typhoon wind field than the unconditional simulation method.
AB - Typhoon winds near its external eye wall are not only strong but also nonstationary with time-varying coherences. This study proposes a conditional simulation method for multivariate nonstationary typhoon winds with time-varying coherences for long-span bridges. The Kriging method for conditional simulation and the time-varying wind spectrum and coherence are first introduced. The decomposition of the time-varying spectrum matrix is then discussed in order to obtain the time-varying correlation functions. It is found that the conventional Cholesky decomposition and the proper orthogonal decomposition (POD) are not suitable and only the square root decomposition (SRD) is appropriate for the decomposition of the spectrum matrix with time-varying coherences. Based on the field-measured nonstationary typhoon wind time histories and the time-varying spectrum and coherence models established for the Stonecutters cable-stayed bridge during Typhoon Hato, the proposed conditional simulation method is finally applied to the bridge and validated by comparing the simulated typhoon wind time histories with the measured ones as well as the unconditional simulation results. The comparative results demonstrate that the conditionally simulated wind time histories are similar to the measured ones and that the proposed conditional simulation method can be used to provide a better typhoon wind field than the unconditional simulation method.
KW - Conditional simulation
KW - Nonstationary typhoon winds
KW - Stonecutters cable-stayed bridge
KW - Time-varying coherence
KW - Typhoon Hato
UR - http://www.scopus.com/inward/record.url?scp=85103414552&partnerID=8YFLogxK
U2 - 10.1016/j.jweia.2021.104599
DO - 10.1016/j.jweia.2021.104599
M3 - Journal article
AN - SCOPUS:85103414552
SN - 0167-6105
VL - 212
JO - Journal of Wind Engineering and Industrial Aerodynamics
JF - Journal of Wind Engineering and Industrial Aerodynamics
M1 - 104599
ER -