Abstract
Twin deck bridges are often required to construct, particularly for large spans and one-way movement of vehicles.
The gap between the two decks is the most critical in the combined deck/bridge response. Nevertheless, this twin deck is
vulnerable to vortex-induced vibration because the central slot modifies the flow profile surrounding a bridge girder. In addition,
the large spans are also susceptible to the flutter effects of wind. Therefore, the study uses computational fluid dynamics to
explore the impact of twin decks with cross beams on aerodynamic coefficients, flutter instability, and vortex-induced vibration.
The features of vortex characteristics have been investigated and inferred in the current study for two structures: with and
without cross beams at various effective angles. The research findings reveal that the vibrating frequency at the lock-in region is
identical for installing cross beams. However, in the structure where the cross beam has not been used, the vibrating frequency
exceeds the lock-in frequency at every effective angle. Still, the flow that passes through the cross beam extracts considerable
energy from the flow field. The research findings revealed that the vibrating frequency at the lock-in region is identical for
installing cross beams. This installation also beats the flutter instability by increasing critical flutter, which makes it a popular
idea for mitigation purposes. Therefore, in these regards, the framework and solution are sustainable for bridge responses under
vortex and flutter domains.
Key Words
computational fluid dynamics; flutter; twin-deck; vortex-induced vibration
Address
Puja Haldar: Department of Civil Engineering, National Institute of Technology Durgapur, West Bengal 713209, India
Somnath Karmakar: Department of Civil Engineering, National Institute of Technology Durgapur, West Bengal 713209, India
Abstract
The rise in the construction of high-rise buildings can be attributed to a number of factors, including the economic
rise of nations, the substantial rural-to-urban migration trend, and innovative technological breakthroughs in construction that
facilitate the growth of high-rise construction. All these factors have contributed to the upward trajectory of high-rise building
construction. However, increase in height of buildings make it susceptible to the undesired effects of high-speed winds. Different
aerodynamic modifications are used to mitigate the aerodynamic oscillations that are caused by the wind. This article aims to
provide a review on different modes of wind induced vibrations in high-rise buildings, aerodynamic modifications in high-rise
buildings to mitigate wind induced loads and pedestrian level wind studies. The effectiveness of these modifications varies with
the degree of modification applied. Helical buildings and tapered buildings show improved wind resistance with increase in
angle of twist and tapering ratio. Small corner modifications up to 10% are more effective than larger corner modifications.
Aerodynamic modifications also improve the pedestrian level wind environment around high-rise buildings with corner
modifications reducing the shear layers and thus subsequently reducing the high wind speed regions whereas setbacks have
exhibited reduction in wind velocities by up to 28-30% in front of them.
Abstract
The evaluation of instantaneous wind flow patterns nearest to building architecture is crucial to ensuring structural
stability, architectural integrity, and pedestrian safety. Particle image velocimetry (PIV), a technique for studying fluid flow by
tracing particles, provides accurate predictions of instantaneous wind velocities (IWV). However, PIV encounters challenges in
specific regions due to laser light-based experimentation, leading to missing data. Consequently, investigating the wind
circulation pattern around buildings becomes more challenging. Numerous ML techniques have been employed to impute
missing wind velocities at random building locations with minimal structural impact. This paper focuses on addressing this
concern by utilizing a machine learning (ML) approach that focuses on estimating unmeasured values in critical areas near
buildings. We employ three distinct ML models: the generative adversarial imputation network (GAIN), multiple imputations by
chained equations (MICE), and neighbor distance imputation (NDI) to estimate missing values around building structures. Our
results indicate that the GAIN technique achieves a remarkable balance, displaying the lowest average mean square error of
0.073 and the highest average R-squared error of 0.965. Furthermore, it effectively captures the distribution of measured values
and provides reliable data for evaluating aerodynamic characteristics and ensuring structural safety.
Key Words
deep learning; generative adversarial imputation network; machine learning; structural safety; urban wind flow
analysis; wind velocity imputation
Address
Istiak Ahammed:Department of Robot and Smart System Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu, 41566, South Korea
Sujeen Song:Earth Turbine, 36 Dongdeok ro 40 gil, Jung gu, Daegu, 41905, South Korea
Gang Hu:School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
Jinwoo An:Department of Civil Engineering, College of Engineering and Computer Science,
The University of Texas Rio Grande Valley, Edinburg, Texas 78539, USA
Bubryur Kim:School of Space Engineering Sciences, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu, 41566, South Korea
Abstract
Inflated membranes are a kind of flexible structure very sensitive to wind load. The enveloping membrane is prone
to be wrinkled under compression with very small stiffness and stresses in the direction perpendicular to wrinkles, resulting in a
significant change in the wind-induced responses of the inflated membrane. This paper studies the effect of wrinkling
deformation on the dynamic behavior of inflated membranes under wind. A thin shell model with random imperfection is
developed based on the stability theory to consider the wrinkling deformation of the enveloping membrane. The internal air is
treated as a kind of potential-based fluid to consider the air-membrane interaction. The governing equations of inflated
membranes are discretized with the finite element method. Square ETFE cushions under the time history of wind pressure
provided by the TPU database are analyzed with the developed finite element model for different initial internal pressures and
wind speeds to investigate the effect of wrinkling deformation. The results indicate that: a) Effect of the wrinkling deformation is
larger on the windward side and smaller on the leeward side with largest magnitudes on the corners; b) The wrinkling
deformation has a larger effect on the stresses with more sensitivity to the varying initial internal pressure and wind speed on the
windward side; and c) Effect of the wrinkling deformation decreases with the increasing initial internal pressure and increases
with the growing wind speed. The present research is helpful to the understanding of the effect of wrinkling deformation on the
dynamic behavior of inflated membranes under wind for their rational design and reliable engineering application.
Key Words
finite element method; inflated membranes; stability theory of plates and shells; wind-induced responses;
wrinkling deformation
Address
Xiaofeng Wang: Xiaofeng Wang, Xujing Cao and Qingshan Yang
Xujing Cao: Xiaofeng Wang, Xujing Cao and Qingshan Yang
Qingshan Yang: School of Civil Engineering, Chongqing University, No.174 Shazhengjie, Shapingba, Chongqing, 400044, China
Abstract
The regions where wind velocity is high, large lateral loads occur on asymmetric and tall buildings. A detailed wind
analysis has been presented in this document on the principal Y-Plan building interfered by two square plan buildings put in a Lshape pattern. Moreover, 0°
to 180°
at a step size of 15° wind angles have been considered. It is revealed by the results that
presence of interfering buildings imposed significant fluctuations in force and wind pressure. For the windward side and the
leeward side, wind flow profile is same but for faces A, G, H and I i.e., faces receiving the blockage of wind by interfering
buildings, it is different. Increasing angle of attack (AOA) increased the velocity to 2.95 m/s in interference case as compared to
velocity of 1.37 m/s in isolated case for 60° wind angle because of blockage of wind and generation of wake region is more in
interference case by the presence of interfering buildings. The highest positive value of interference factor (I.F.) is for Face H
and Face I with values of 2.019 and 2.454 respectively for 0° AOA of wind while the most negative value is for Face B with
value of -1.702 for 0° AOA. Most of the faces have the values of interference factor near about 1 indicating that interfering
buildings on these faces do not produce much effect on the principal building.
Key Words
asymmetric; interference; leeward; numerical analysis; wind angle; windward
Address
Faiz Akram:Department of Civil Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, India
Shanku Mandal:Department of Civil Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, India
Sujit Kumar Dalui:Department of Civil Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, India
