Abstract
In recent years, there have been an increasing number of experimental studies showing the need to include
robustness criteria in the design process to develop complex active control designs for practical implementation. The paper
investigates the crosswind aerodynamic parameters after the blocking phase of a two-dimensional square cross-section structure
by measuring the response in wind tunnel tests under light wind flow conditions. To improve the accuracy of the results, the
interpolation of the experimental curves in the time domain and the analytical responses were numerically optimized to finalize
the results. Due to this combined effect, the three aerodynamic parameters decrease with increasing wind speed and
asymptotically affect the upper branch constants. This means that the aerodynamic parameters along the density distribution are
minimal. Taylor series are utilized to describe the fuzzy nonlinear plant and derive the stability analysis using polynomial
function for analyzing the aerodynamic parameters and numerical simulations. Due to it will yield intricate terms to ensure
stability criterion, therefore we aim to avoid kinds issues by proposing a polynomial homogeneous framework and utilizing
Euler's functions for homogeneous systems. Finally, we solve the problem of stabilization under the consideration by SOS (sum
of squares) and assign its fuzzy controller based on the feasibility of demonstration of a nonlinear system as an example.
Key Words
feedback and feedforward; fuzzy LMI control; improved optimal control performance; linearization method
Address
Timothy Chen:1)Guangdong University of Petrochem Technol, Sch Sci, Maoming City, Kuan-Du Avenue, No. 139, P525000, P.R. China
2)Division of Eng App Sci, Caltech, CA 91125, U.S.A.
Yahui Meng:Guangdong University of Petrochem Technol, Sch Sci, Maoming City, Kuan-Du Avenue, No. 139, P525000, P.R. China
Rayuan Wang:Guangdong University of Petrochem Technol, Sch Sci, Maoming City, Kuan-Du Avenue, No. 139, P525000, P.R. China
ZY Chen:1)Guangdong University of Petrochem Technol, Sch Sci, Maoming City, Kuan-Du Avenue, No. 139, P525000, P.R. China
2)Division of Eng App Sci, Caltech, CA 91125, U.S.A.
Abstract
Wind Driven Rain (WDR) poses a significant threat to the building environment, especially in hurricane prone
regions by causing interior and content damage during tropical storms and hurricanes. The damage due to rain intrusion depends
on the total amount of water that enters the building; however, owing to the use of inadequate empirical methods, the amount of
water intrusion is difficult to estimate accurately. Hence, the need to achieve full-scale testing capable of realistically simulating
rain intrusion is widely recognized. This paper presents results of a full-scale experimental simulation at the NHERI Wall of
Wind Experimental Facility (WOW EF) aimed at obtaining realistic rain characteristics as experienced by structures during
tropical storms and hurricanes. A full-scale simulation of rain in strong winds would allow testing WDR intrusion through
typical building components. A study of rain intrusion through a sliding glass door is presented, which accounted for the effects
of multiple wind directions, test durations and wind speeds; configurations with and without shuttering systems were also
considered. The study showed that significant levels of water intrusion can occur during conditions well below current design
levels. The knowledge gained through this work may enhance risk modeling pertaining to loss estimates due to WDR intrusion
in buildings, and it may help quantify the potential reduction of losses due to the additional protection from shuttering systems
on sliding glass doors during winds.
Key Words
hurricane damage; interior damage; rain intrusion; sliding doors; wall of wind; wind-driven rain
Address
Krishna Sai Vutukuru and James Erwin:Extreme Events Institute, Florida International University, United States
Arindam Gan Chowdhury:1)Extreme Events Institute, Florida International University, United States
2)Department of Civil and Environmental Engineering, Florida International University, United States
Abstract
Modern high-rise tower designs incorporating recessed balcony cavity spaces can be prone to high-frequency and
narrow-band Rossiter aerodynamic excitations under glancing incident winds that can harmonize and compete with recessed
balcony volume acoustic Helmholtz modes and facade elastic responses. Resulting resonant inertial wind loading to balcony
facades responding to these excitations is additive to the peak design wind pressures currently allowed for in wind codes and can
present as excessive facade vibrations and sub-audible throbbing in the serviceability range of wind speeds. This paper presents
a methodology to determine Cavity Amplification Factors to account for façade resonant inertial wind loads resulting from
balcony cavity aero-acoustic-elastic resonances by drawing upon field observations and the results of full-scale monitoring and
model-scale wind tunnel tests. Recessed balcony cavities with single orifice type openings and located within curved façade
tower geometries appear particularly prone. A Cavity Amplification Factor of 1.8 is calculated in one example representing
almost a doubling of local façade design wind pressures. Balcony facade and tower design recommendations to mitigate wind
induced aero-acoustic-elastic resonances are provided.
Key Words
balcony; Cavity Amplification Factor; Helmholtz; resonant; Rossiter
Address
Matthew J. Glanville:CPP, Unit 2, 500 Princes Highway, St Peters, NSW, 2044, Australia
John D. Holmes:JDH Consulting, P.O. Box 369, Mentone, Vic, 3194, Australia
Abstract
Large-span cantilevered roof represents a unique type of structure that is vulnerable to wind loads. Inspired by the need
to maximumly reducing the rooftop wind loads, this study examined the feasibility of positioning vented slots on the leading edge,
and the effectiveness of such aerodynamic mitigation measures are assessed via both physical and numerical simulations. The
reliability of numerical simulation was evaluated via comparisons with the wind tunnel tests. The results indicated that, the variation
of venting hole arrangement can cause significant change in the rooftop wind load characteristics. For the cases involved in this
study, the maximum reduction of mean and peak wind suction coefficients are found to be 9% and 8% as compared to the original
circular slot without venting holes. In addition, the effect of slot shape is also evident. It was shown that the triangular shaped slot
tends to increase the wind suction near the leading edge, whereas the hexagonal and octagonal shaped slots are found to decrease the
wind suction. In particular, with the installation of octagonal shaped slot, the maximum reduction of wind suction coefficients near
the leading edge reaches up to 31% as compared to the circular shaped slot, while the maximum reduction of mean wind suction
coefficients is about 30%.
Key Words
aerodynamic mitigation; large-span cantilevered roof; numerical simulation; wind pressure distribution; wind
tunnel test
Address
Chen Fubin, Wang Weijia and Yang Danqing:School of Civil Engineering, Changsha University of Science and Technology, Changsha, 410082, China
Shu Zhenru:School of Civil Engineering, Central South University, Changsha, 410075, China
Abstract
Guyed mast structures exhibit characteristics such as high flexibility, low mass, small damping ratio, and large
aspect ratio, leading to a complex wind-induced vibration response mechanism. This study analyzed the time- and frequencydomain characteristics of the wind-induced response of a guyed mast structure using measured acceleration response data
obtained from the Shenzhen Meteorological Gradient Tower (SZMGT). Firstly, 734 sets of 1-hour acceleration samples
measured from 0:00 October 1, 2021, to 0:00 November 1, 2021, were selected to study the vibration shapes of the mast and the
characteristics of the generalized extreme value (GEV) distribution. Secondly, six sets of typical samples with different vibration
intensities were further selected to explore the Gaussian property and modal parameter characteristics of the mast. Finally, the
modal parameters of the SZMGT are identified and the identification results are verified by finite element analysis. The findings
revealed that the guyed mast vibration shape exhibits remarkable diversity, which increases nonlinearly along the height in most
cases and reaches a maximum at the top of the tower. Moreover, the GEV distribution characteristics of the 734 sets of samples
are closer to the Weibull distribution. The probability distribution of the structural wind vibration response under strong wind is
in good agreement with the Gaussian distribution. The structural response of the mast under wind loading exhibits multiple
modes. As the structural response escalates, the first three orders of modal energy in the tower display a gradual increase in
proportion.
Key Words
acceleration response; filed measurements; guyed mast; modal identification; probability density characteristic
Address
Zhe Wang, Muguang Liu, Lei Qiao and Zhuangning Xie:School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong, 510641, China
Hongyan Luo and Chunsheng Zhang:Shenzhen National Climate Observatory, Meteorological Bureau of Shenzhen Municipality, Shenzhen, Guangdong, 518040, China
