scholarly journals A Performance-Based Wind Engineering Framework for Engineered Building Systems Subject to Hurricanes

2021 ◽  
Vol 7 ◽  
Author(s):  
Zhicheng Ouyang ◽  
Seymour M.J. Spence
Keyword(s):  
Storm Track ◽  
Stochastic Simulation Algorithm ◽  
Building Envelope ◽  
Wind Pressure ◽  
Time Dependent ◽  
Wind Engineering ◽  
Full Description ◽  
Wind Event ◽  
Significant Research ◽  
Hurricane Hazard

Over the past decade, significant research efforts have been dedicated to the development of performance-based wind engineering (PBWE). Notwithstanding these efforts, frameworks that integrate the damage assessment of the structural and envelope system are still lacking. In response to this need, the authors have recently proposed a PBWE framework that holistically treats envelope and structural damages through progressive multi-demand fragility models that capture the inherent coupling in the demands and damages. Similar to other PBWE methodologies, this framework is based on describing the hurricane hazard through a nominal straight and stationary wind event with constant rainfall and one-hour duration. This study aims to develop a PBWE framework based on a full description of the hurricane hazard in which the entire evolution of the storm track and time-dependent wind/rain fields is simulated. Hurricane-induced pressures impacting the building envelope are captured through the introduction of a non-stationary/-straight/-Gaussian wind pressure model. Time-dependent wind-driven rain is modeled through a computational fluid dynamics Eulerian multiphase framework with interpolation schemes for the rapid computation of wind-driven rain intensities over the building surface. Through the development of a conditional stochastic simulation algorithm, the envelope performance is efficiently characterized through probabilistic metrics associated with rare events of design interest. The framework is demonstrated through analyzing a 45-story archetype building located in Miami, FL, for which the envelope performance is estimated in terms of a suite of probabilistic damage and loss metrics. A comparative study is carried out in order to provide insights into the differences that can occur due to the use of nominal hurricane models.

A RESILIENCE-BASED ASSESSMENT OF THE PERFORMANCE OF RESIDENTIAL COMMUNITIES SUBJECT TO HURRICANE HAZARD

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ahmed U. Abdelhady ◽  
Seymour M.J. Spence ◽  
Jason McCormick
Keyword(s):  
Community Resilience ◽  
Recovery Process ◽  
Simulation Method ◽  
Wind Pressure ◽  
Community Recovery ◽  
Recovery Function ◽  
Residential Neighborhood ◽  
Hurricane Hazard ◽  
Hurricane Vulnerability ◽  
The Impact

Hurricanes are among the most devastating and costliest natural hazards. This devastating impact urged governments and policymakers to implement mitigation plans and strategies that can enhance the community’s resilience against hurricanes. A fundamental step to gauge the performance and effectiveness of these mitigations plans is to develop computational frameworks that can provide a probabilistic assessment of the resilience of the community. Therefore, this paper presents a framework to probabilistically estimate the resilience of residential wooden buildings against hurricane winds. The framework estimates the post-hurricane damage due to dynamic wind pressure and the impact of windborne debris using an engineering-based hurricane vulnerability. The building recovery function is then estimated by integrating the estimated damage with a building-level recovery model. By aggregating building recovery functions, the community recovery function is obtained. The Monte Carlo simulation method is used to account for uncertainties related to the hazard intensity, community vulnerability, and recovery process. The framework is applied to a residential neighborhood in Miami, FL. This framework can help decision-makers to compare current community resilience with target levels, identify the gap, and set strategies to improve community resilience.

scholarly journals Dust Driven Winds from Pulsating Stars

1993 ◽  
Vol 137 ◽  
pp. 572-574 ◽  
Author(s):  
E.A. Dorfi ◽  
M.U. Feuchtinger ◽  
S. Höfner
Keyword(s):  
The Self ◽  
Time Dependent ◽  
Full Description ◽  
Stellar Winds ◽  
Dust Formation ◽  
Radiation Hydrodynamics ◽  
Simple Description ◽  
Pulsating Stars ◽  
Self Consistent ◽  
Different Parts

The cool extended atmospheres of late type giants are sites where dust formation takes place. Radiation pressure on the dust grains is an important force for driving the slow but massive winds observed in such objects. Existing calculations of dust driven stellar winds (e.g. Bowen 1988, Fleischer et al. 1991) suffer from the fact that they include approximations at various levels for different parts of the problem like the hydrodynamics or the dust formation. Furthermore they do not include time-dependent radiative transfer.In order to overcome these insufficiencies we plan to calculate self-consistent models of dust driven winds with a full description of both the radiation hydrodynamics and the time-dependent dust formation. As a first step, however, we concentrate our investigations on the self-consistent description of the radiation hydrodynamics adopting only a simple description of the dust opacities.

Non-Gaussian time-dependent statistics of wind pressure processes on a roof structure

2016 ◽  
Vol 23 (4) ◽  
pp. 275-300 ◽  
Author(s):  
M.F. Huang ◽  
Song Huang ◽  
He Feng ◽  
Wenjuan Lou
Keyword(s):  
Wind Pressure ◽  
Time Dependent ◽  
Roof Structure ◽  
Non Gaussian ◽  
Gaussian Time

Wind Pressure Coefficients Determination for Pre-Homogenization Storage in Cement Mill

2011 ◽  
Vol 94-96 ◽  
pp. 1026-1030
Author(s):  
Yue Ming Luo ◽  
Yue Yin ◽  
Xi Liang Liu
Keyword(s):  
Wind Tunnel ◽  
Spherical Shell ◽  
Rapid Development ◽  
Wind Tunnel Test ◽  
Wind Pressure ◽  
Wind Engineering ◽  
Pressure Coefficients ◽  
Continuous Innovation ◽  
Structural Style ◽  
Wind Pressures

Due to the increasing of wind disaster, structural wind engineering arouses more and more attention recently, with rapid development on spatial structure and continuous innovation of structural style. The main purpose of structural wind engineering is to calculate the wind pressure coefficients of structure. In this paper, the numerical wind tunnel method (NWTM), based on the Computational Fluid Dynamics (CFD), is applied to study wind load. The wind pressure coefficients of reticulated spherical shell with the 4.6m high wall were first determined, using the NWTM. The results are then compared with the wind tunnel test (WTT) and good agreement is found. The feasibility and reliability of NWTM were then verified. As the second example, NWTM is carried out to predict wind-induced pressure on reticulated spherical shell without wall. Further the distribution behavior of wind pressures on this kind of structures is discussed which could provide professionals the reference for the design of structure.

scholarly journals THE ANALYSIS OF SPEED AND PRESSURE OF WIND IN RAINY WEATHER/VĖJO SLĖGIO IR JO GREIČIO KITIMO LYJANT ANALIZĖ

2001 ◽  
Vol 7 (1) ◽  
pp. 68-72
Author(s):  
Valdas Paukštys ◽  
Vytautas Stankevičius
Keyword(s):  
Surface Layer ◽  
Wind Velocity ◽  
Building Envelope ◽  
Wind Pressure ◽  
Considerable Part ◽  
Exterior Surface ◽  
Lime Mortar ◽  
Average Wind ◽  
Rainy Weather ◽  
Average Wind Velocity

It is not enough to investigate only the effect of wind on buildings, because deterioration of exterior surfaces of buildings is caused by wind and moisture together. A considerable part of rain gets into the exterior surface of enclosure, penetrates deep down and destroys the material of surface layer. The rain passes through enclosure construction and its surface layer due to wind pressure, through joints of the elements and cracks caused by improper transportation as well as by an inaccurate assembling. At present, new multilayer constructional elements are used for building envelope having numerous assembling seams, therefore, the combined influence of rain and wind becomes rather dangerous. It was established that the wind velocity during the rain is one of the main reasons predetermining moisture penetration into protective-decorative walls made of sand-lime brick with split surface, on concrete-lime mortar, according to the analysis of combined influence of the climate by research data [4]. The total effect of rain and wind on the humidity condition of exterior layers is described. Distribution of real wind velocity was estimated according to the data of the last 10 years. It was found that in Kaunas the average wind velocity increases from 3,4 m/s when the rain is absent up to 4,3 m/s and in Vilnius—the average wind velocity increases from 2,9 m/s when the rain is absent up to 3,7 m/s with an increase of approximately 26%, while in Klaipeda the average wind velocity increases from 3,6 m/s when the rain is absent up to 5,1 m/s with an increase of approximately 42%. On the base of the investigations carried out the suggestion is proposed to use the maximum and mean wind velocity values at the rain for estimating the effect of wind to the moisture behaviour in building elements.

scholarly journals Stochastic simulation of rain intrusion through small defects due to water rivulet overpressure. Introducing a driving rain leakage potential

2021 ◽  
Vol 2069 (1) ◽  
pp. 012052
Author(s):  
C.-E. Hagentoft ◽  
L. Olsson
Keyword(s):  
Building Envelope ◽  
Wind Pressure ◽  
Weather Data ◽  
Wall Structure ◽  
Building Stock ◽  
Major Threat ◽  
The Mean ◽  
The Cost ◽  
Interior Side ◽  
Driving Rain

Abstract There is a need of upgrading the old building stock with respect to the thermal insulation of the building envelope and specifically the façades. There are several systems on the market, and some are quite new and innovative. To bring down the cost some of the systems many are based on prefabricated moisture tight insulated units. This means that in case there is moisture tight barrier on the interior side, two moisture tight barriers surround the wall structure. The leakage of driving rain into the structure then represents a major threat to the durability of these systems. This paper investigates the pressure build up in water rivulets running down a façade acting together with the wind pressure. A driving rain leakage potential is introduced. Using real weather data years and Monte Carlo Simulations, the mean and standard deviation of the annual leakage through small hole is estimated. The examples show that the leakage can reach a level 0-0.5 liter/year for a hole with a diameter of 1-2 mm, and 0.5-3 liter/year for a diameter of 3-4 mm.

scholarly journals Analysis of Wind Speed and Wind Pressure on the Facades in Frequency Domain for the Modelling of Air Change Rate

2020 ◽  
Vol 172 ◽  
pp. 09005
Author(s):  
Krystyna Pietrzyk
Keyword(s):  
Wind Speed ◽  
Frequency Domain ◽  
Wind Direction ◽  
High Frequency ◽  
Pressure Coefficient ◽  
Building Envelope ◽  
Wind Pressure ◽  
Change Rate ◽  
Air Change Rate ◽  
Air Exchange

Air exchange in buildings is driven by pressure difference across the building envelope caused by wind and difference in density between external and internal air. The evaluation of the influence of wind on the air change rate is usually limited to the analysis of the hourly mean wind speed. Wind is a random phenomenon characterized by the broad energy spectrum. The high frequency part can be responsible for the oscillation of the air through the openings resulting in the increased air exchange. Wind pressure coefficient on the leeward site mostly depends on the form characteristics of the object in relation to wind direction. The analysis of wind speed and wind pressure on the facades in frequency domain can deliver interesting data to air change rate model. Some of the results of continuous measurements carried out on a single-family house for 8 months are presented in frequency domain. The statistics of wind speed, wind direction and pressure differences across the 6 building components are calculated. The wind turbulence and the pressure fluctuations on the facades and the roof of the building are being investigated using energy spectra of their signals. Farther analysis of the experimental results is needed to be able to include high frequency wind in the infiltration model.

Quantum Dynamics Using The Time-Dependent Schrödinger Equation

2006 ◽  
Author(s):  
Abraham Nitzan
Keyword(s):  
Schrödinger Equation ◽  
Quantum Dynamics ◽  
Schrodinger Equation ◽  
Time Dependent ◽  
Full Description ◽  
Quantum Mechanical ◽  
Condensed Phases ◽  
Full Picture ◽  
Linear Differential ◽  
External Forces

This chapter focuses on the time-dependent Schrödinger equation and its solutions for several prototype systems. It provides the basis for discussing and understanding quantum dynamics in condensed phases, however, a full picture can be obtained only by including also dynamical processes that destroy the quantum mechanical phase. Such a full description of quantum dynamics cannot be handled by the Schrödinger equation alone; a more general approach based on the quantum Liouville equation is needed. This important part of the theory of quantum dynamics is discussed in Chapter 10. Given a system characterized by a Hamiltonian Ĥ , the time-dependent Schrödinger equation is For a closed, isolated system Ĥ is time independent; time dependence in the Hamiltonian enters via effect of time-dependent external forces. Here we focus on the earlier case. Equation (1) is a first-order linear differential equation that can be solved as an initial value problem.

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