Time Domain Flutter and Buffeting Response Analysis of Bridges

2000 ◽  
Vol 126 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Xinzhong Chen ◽  
Masaru Matsumoto ◽  
Ahsan Kareem
Keyword(s):  
Time Domain ◽  
Response Analysis ◽  
Buffeting Response

Objective-based equivalent static wind loads for long-span bridges

2019 ◽  
Author(s):  
Zachary J. Taylor ◽  
Pierre-Olivier Dallaire ◽  
Stoyan T. Stoyanoff
Keyword(s):  
Time Domain ◽  
Experimental Testing ◽  
Wind Loads ◽  
Response Analysis ◽  
Long Span Bridges ◽  
Buffeting Response ◽  
Long Span ◽  
Equivalent Static Wind Loads ◽  
The Time Domain ◽  
Key Aspects

<p>The process to arrive at design wind loads for long-span bridges involves experimental testing and analytical methods. Time domain simulations are becoming increasingly common and many available studies demonstrate results of buffeting response analysis in the time domain. However, there is significantly more to the process than the response analysis to derive wind loads that can be applied practically for design. The current study focuses on two key aspects required to derive design wind loads: prediction of the peak modal deflection and derivation of modal combination coefficients using objective functions.</p>

Nonlinear Ship Loads: Stochastic Models for Extreme Response

1998 ◽  
Vol 42 (01) ◽  
pp. 46-55
Author(s):  
Rune Torhaug ◽  
Steven R. Winterstein ◽  
Arne Braathen
Keyword(s):  
Time Domain ◽  
Stochastic Models ◽  
Stochastic Analysis ◽  
Short Wave ◽  
Response Analysis ◽  
Correct Result ◽  
Sea State ◽  
Extreme Response ◽  
Computational Resources ◽  
The Cost

In this study we focus on stochastic analysis methods for selective simulations, and we consider the extreme midspan moment of a fast-moving ship subjected to random Gaussian waves. We concentrate on analysis within a stationary sea state and our purpose is to accurately estimate hourly maximum ship response (compared with the correct result per hour) within a sea state with as little computational resources as possible. We consider how the use of a limited number of short simulations with "critical wave episodes" (short wave segments which are likely candidates to produce extreme response in the simulated hour-long history) reduces the cost of nonlinear time-domain ship response analysis.

Buffeting Response Analysis of Stonecutters Bridge

2005 ◽  
Vol 12 (2) ◽  
pp. 8-21
Author(s):  
Michael C H Hui ◽  
Q S Ding ◽  
Y L Xu
Keyword(s):  
Response Analysis ◽  
Buffeting Response

Fast Frequency-Domain Algorithm for Estimating the Dynamic Wind-Induced Response of Large-Span Roofs Based on Cauchy’s Residue Theorem

2018 ◽  
Vol 18 (03) ◽  
pp. 1850037 ◽  
Author(s):  
Ning Su ◽  
Zhenggang Cao ◽  
Yue Wu
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Rational Functions ◽  
Induced Response ◽  
Response Analysis ◽  
Residue Theorem ◽  
Coupling Effects ◽  
Large Span ◽  
Modal Coupling ◽  
Cauchy’S Residue Theorem

Wind-induced response analysis is an important process in the design of large-span roofs. Conventional time-domain methods are computationally more expensive than frequency-domain algorithms; however, the latter are not as accurate because of the ill-treatment of the modal coupling effects. This paper revisited the derivations of the frequency-domain algorithm and proposed a fast algorithm for estimating the dynamic wind-induced response considering duly the modal coupling effects. With the wind load cross-spectra modeled by rational functions, closed-form solutions to the frequency-domain integrals can be calculated by Cauchy’s residue theorem, rather than by numerical integration, thereby reducing the truncation errors and enhancing the efficiency of computation. The algorithm is applied to the analysis of a grandstand roof and a spherical dome. Through comparison with time domain analyses results, the algorithm is proved to be reliable. A criterion of the coupling modal combination was suggested based on the cumulative modal contribution rate of over 70%.

Analysis of Brief Tension Loss in TLP Tethers

1988 ◽  
Vol 110 (1) ◽  
pp. 43-47 ◽  
Author(s):  
J. N. Brekke ◽  
T. N. Gardner
Keyword(s):  
Time Domain ◽  
Large Diameter ◽  
Nonlinear Effects ◽  
Response Analysis ◽  
Bending Stress ◽  
Large Wave ◽  
Wave Trough ◽  
Design Selection ◽  
The Time Domain ◽  
Selection Of

The avoidance of “slack” tethers is one of the factors which may establish the required tether pretension in a tension leg platform (TLP) design. Selection of an appropriate safety factor on loss of tension depends on how severe the consequences may be. It is sometimes argued that if tethers go slack, the result may be excessive platform pitch or roll motions, tether buckling, or “snap” or “snatch” loading of the tether. The results reported here show that a four-legged TLP would not be susceptible to larger angular motions until two adjacent legs lose tension simultaneously. Even then, this analysis shows that a brief period of tether tension loss (during the passage of a large wave trough) does not lead to excessive platform motion. Similarly, momentary tension loss does not cause large bending stress in the tether or significant tension amplification as the tether undergoes retensioning. This paper presents TLP platform and tether response analysis results for a representative deepwater Gulf of Mexico TLP with large-diameter, self-buoyant tethers. The time-domain, dynamic computer analysis included nonlinear effects and platform/tether coupling.

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