Non-Stationary Turbulent Wind Field Simulation of Long-Span Bridges Using the Updated Non-Negative Matrix Factorization-Based Spectral Representation Method

Abstract

Numerical simulation of the turbulent wind field on long-span bridges is an important task in structural buffeting analysis when it comes to the system non-linearity. As for non-stationary extreme wind events, some efforts have been paid to update the classic spectral representation method (SRM) and the fast Fourier transform (FFT) has been introduced to improve the computational efficiency. Here, the non-negative matrix factorization-based FFT-aided SRM has been updated to generate not only the horizontal non-stationary turbulent wind field, but also the vertical one. Specifically, the evolutionary power spectral density (EPSD) is estimated to characterize the non-stationary feature of the field-measured wind data during Typhoon Wipha at the Runyang Suspension Bridge (RSB) site. The coherence function considering the phase angles is utilized to generate the turbulent wind fields for towers. The simulation accuracy is validated by comparing the simulated and target auto-/cross-correlation functions. Results show that the updated method performs well in generating the non-stationary turbulent wind field. The obtained wind fields will provide the research basis for analyzing the non-stationary buffeting behavior of the RSB and other wind-sensitive structures in adjacent regions.

Laplacian Split-BREAK Process with Application in Dynamic Analysis of the World Oil and Gas Market

“…Theorem 3. Let 𝑋 be the time series defined by Equations ( 8) and (9). Then, for any 𝑥 ∈ ℝ and 𝑡 0, 1, … , 𝑇, the CDF of the RVs 𝑋 is given by: Finally, we define another important LSB series, the so-called increments of the LSB process:…”

“…Based on earlier assumptions, the basic properties of this series, obtained by some simple computations, can be expressed as follows: Theorem 2. Let (X t ) be the time series defined by Equations ( 8) and (9). Then, the mean and the variance of this series are, respectively,…”

“…A particular problem arises when the observed time series have a nonstationary dynamic, which usually affects the greater complexity of their stochastic structure (for more recent studies, see, c.f. [9][10][11][12][13][14]). To solve these and similar problems, Engle and Smith [15] proposed the stochastic permanent breaking (STOPBREAK) process, which was later examined by many authors, especially in the domain of structural and permanent changes in the fluctuations of some real-world data [16][17][18][19][20].…”

Spatial Modelling in Environmental Analysis and Civil Engineering

“…As an example, the problem described in the special issue is a numerical simulation of a turbulent wind field on long-span bridges. Xu et al [8] optimized the spectral representation method and the obtained results show that the updated method works well in generating a non-stationary turbulent wind field. The obtained wind fields will serve as the research basis for the analysis of non-stationary shock behaviour and other wind-sensitive structures.…”

Asymptotic Properties and Application of GSB Process: A Case Study of the COVID-19 Dynamics in Serbia

“…The main goal of this paper is a more detailed investigation of the non-stationary components (time series) of the GSB model. These series naturally have a more complex stochastic structure, but they are of particular interest in contemporary research [13][14][15][16][17][18]. To this end, the asymptotic properties of distributions of the GSB series will also be of specific interest.…”