Effect of wind loads on the stability of conical tanks

2011 ◽  
Vol 38 (4) ◽  
pp. 444-454 ◽  
Author(s):  
G. Hafeez ◽  
A.M. El Ansary ◽  
A.A. El Damatty
Keyword(s):  
Hydrostatic Pressure ◽  
Design Procedure ◽  
Element Model ◽  
Wind Load ◽  
Combined Effect ◽  
Wind Loads ◽  
Wind Loading ◽  
Bottom Part ◽  
Conical Tanks ◽  
The Stability

During the past few decades, a number of conical tanks have collapsed in various locations around the globe. Previous studies attributed the reason of collapse to inadequate thickness of the conical vessel especially at the bottom part. Most of the previous studies focused on studying the stability of conical tanks under the effect of only hydrostatic pressure. The current study focuses on studying the combined effect of wind loading and hydrostatic pressure on the stability of conical tanks. The study is conducted numerically, using a three-dimensional finite element model that is developed in-house. The critical imperfection shapes leading to minimum buckling capacity of conical shells under wind load alone, and under the combined effect of wind load and hydrostatic pressure, are determined. The study shows that a non-axisymmetric imperfection shape leads to minimum buckling capacity of empty conical tanks subjected to wind loads, while an axisymmetric distribution is noticed in the case of conical tanks under the combined effect of wind loads and hydrostatic pressure. In addition, the current study assesses the adequacy of an existing design procedure, which accounts for hydrostatic pressure, when the combination of hydrostatic pressure and wind load is considered.

Wind resistance of a narrow partially built house

1986 ◽  
Vol 13 (3) ◽  
pp. 375-381
Author(s):  
Ronald A. Macnaughton
Keyword(s):  
Key Words ◽  
Wind Load ◽  
Building Code ◽  
Wind Loads ◽  
Wind Loading ◽  
Critical Component ◽  
Wind Resistance ◽  
Early Stages ◽  
Resistance Analysis

This paper contains a wind load and resistance analysis for a type of structure that has frequently failed: partially built houses. The critical component of such structures is identified to be the first-storey shearwalls running across the house. The calculated racking strength of that storey is compared to the wind loading the structure would be expected to resist if it were engineered. Various methods are proposed for builders to provide these structures with more wind resistance during the early stages of construction. Differences between Canadian codes and codes in other jurisdictions with respect to this are pointed out. Key words: wind loads, houses, failure, wind bracing, temporary bracing, shearwalls, fibreboard, sheathing, permanent bracing, racking strength, construction procedures, nailing, building code.

scholarly journals Wind-Induced Vibration Control of Dalian International Trade Mansion by Tuned Liquid Dampers

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Hong-Nan Li ◽  
Ting-Hua Yi ◽  
Qin-Yang Jing ◽  
Lin-Sheng Huo ◽  
Guo-Xin Wang
Keyword(s):  
International Trade ◽  
Vibration Control ◽  
Design Procedure ◽  
Element Model ◽  
Wind Loading ◽  
Three Dimension ◽  
Analysis And Design ◽  
Tuned Liquid Dampers ◽  
Liquid Dampers ◽  
Wind Induced Vibration

This paper focuses on the wind-induced vibration control of the Dalian international trade mansion (DITM) by using the tuned liquid dampers (TLDs). To avoid the intensive computationally demanding problem caused by tens of thousand of degrees of freedom (DOF) of the structure in the numerical analysis, the three-dimension finite element model of the DITM is first simplified to the equivalent series multi-DOF system. The wind loading is subsequently simulated by the Davenport model according to the structural environmental condition where the actual samples of wind speed are measured. Following that, the shallow- and deep-water wave theories are applied to model the liquid sloshing inside TLDs, the tank sizing, and required water depth, and numbers of TLDs are given according to the numerical results of different cases. Comparisons between uncontrolled and controlled displacement and acceleration responses of the DITM under wind forces show that the designed shallow tank has higher efficiency than the deep one, which can effectively reduce the structural response amplitudes and enhance the comfortableness of the mansion. The preliminary TLD design procedure presented in this paper could be applied as a reference to the analysis and design of the wind-induced vibration for high-rise buildings using the TLD.

scholarly journals Determining the Magnitude of Wind Loads on Structures in Kenya according to the Eurocodes

2021 ◽  
Author(s):  
Muthomi Munyua
Keyword(s):  
Wind Speed ◽  
Structural Design ◽  
Wind Load ◽  
Wind Data ◽  
Wind Loads ◽  
Wind Loading ◽  
Design Code ◽  
Wind Speeds ◽  
The Uk

This paper provides guidance on the use of existing wind data in Kenya with the Eurocodes despite the absence of the local national annexes. The determination of wind loads in the structural design of buildings according to the Eurocode Standard KS EN 1991-1-4:2005 in Kenya is challenging because of the lack of the Kenya National Annex. The design code commonly used in Kenya is CP3-Chapter V-2:1972 that uses the three-second gust duration. This gust duration results in higher magnitudes of wind loads that end up making the structures unnecessarily robust and uneconomical. Using the Eurocodes has the promise of achieving more economical designs because it uses the 10-minute gust duration. The 10-minute gust duration results in typically lower magnitudes of wind loads than the three-second gust duration for the same wind speed. Kenya adopted the Eurocodes in September 2012 but has not yet developed its national annexes opting instead to use the UK National Annexes. The UK National Annexes are applicable to Kenya in some scenarios but not in others such as wind loading. The lack of the Kenya National Annexes has led to difficulties in the adoption of the Eurocodes. This paper outlines a procedure in which the existing wind data given in three-second gusts could be converted to 10-minute wind speeds. Once converted, the method described in the UK National Annex could then be followed selectively to determine the wind load on a structure. Lastly, the paper recommends that wind data collected from 1977 to 2021 by the Kenya Meteorological Department be incorporated to the development of the wind map for the Kenya National Annex to KS EN 1991-1-4:2005

scholarly journals Study on the Dynamic Characteristics of Subway Tunnel Billboard Under Wind and Vibration Loads

2020 ◽  
Author(s):  
Yong-hang Sun ◽  
Zhong Luo ◽  
Yu Wang ◽  
Kai Wei ◽  
Gui-xin Han
Keyword(s):  
Dynamic Characteristic ◽  
Equivalent Stress ◽  
Structural Response ◽  
Element Model ◽  
Wind Load ◽  
Subway Tunnel ◽  
Vibration Load ◽  
Computational Fluid Dynamics Cfd ◽  
The Stability ◽  
Train Induced Vibration

Abstract In order to avoid the damage of billboards in the subway tunnel, the dynamic characteristic of them subjected to the wind load, the train-induced vibration load and both of them (multi-load) were analyzed. First, computational fluid dynamics (CFD) was used to simulate unsteady airflow when a train runs in tunnel. Second, the train-induced vibration load is obtained by the fitting formula. Finally, a finite element model of Shenyang Metro was built and the response of the billboard under different loads were obtained. The result shows that the structural response of the billboard under multi-load is severer than each single load. For the wind load, it has a greater influence on the equivalent stress of the billboard, while for the vibration load, it has a greater influence on the acceleration of the billboard. The response under multiple loads includes the characteristics of two loads acting separately. This study reveals the dynamic characteristic of billboards under different loads, which will help to improve the stability and safety life of them.

Nonlinear behaviour of reinforced concrete conical tanks under hydrostatic pressure

2016 ◽  
Vol 43 (2) ◽  
pp. 85-98 ◽  
Author(s):  
Ahmed A. Elansary ◽  
Ashraf A. El Damatty ◽  
Ayman M. El Ansary
Keyword(s):  
Reinforced Concrete ◽  
Hydrostatic Pressure ◽  
Water Pressure ◽  
Fem Analysis ◽  
Element Model ◽  
Material Nonlinearity ◽  
Nonlinear Behaviour ◽  
Maximum Deflection ◽  
Analysis And Design ◽  
Conical Tanks

Among the different shapes available, conical vessels are commonly used as water reservoirs because of their large storage capacities. Motivated by the lack of guidelines available for their analysis and design in the existing codes of practice, this study focuses on analyzing reinforced concrete conical tanks under the effect of hydrostatic pressure. A finite element model (FEM), which accounts for material nonlinearity experienced in reinforced concrete, is developed. This nonlinearity is considered by implementing a concrete plasticity constitutive model in the developed FEM. Analysis of a set of 12 tanks with different practical dimensions is performed under hydrostatic water pressure. The variations of meridional and hoop stresses through the thickness of the tanks are determined by plotting the stresses at the outer faces of the tank’s wall. The effect of including material nonlinearity in the FEM on the deformed shape is assessed. The developed FEM is used to find the location of maximum deflection and stresses. The variations in the maximum deflection and stresses with the dimensional parameters of the conical vessel are reported.

scholarly journals Determining the Magnitude of Wind Loads on Structures in Kenya according to the Eurocodes

2021 ◽  
Author(s):  
Muthomi Munyua
Keyword(s):  
Wind Speed ◽  
Structural Design ◽  
Wind Load ◽  
Wind Data ◽  
Wind Loads ◽  
Wind Loading ◽  
Code Of Practice ◽  
Wind Speeds ◽  
The Uk

This study provided guidance on the use of existing wind data in Kenya with the Eurocodes despite the absence of the local national annexes. The determination of wind loads in the structural design of buildings according to the Eurocode Standard KS EN 1991-1-4:2005 had several challenges. The code of practice commonly used in Kenya was CP3-Chapter V-2:1972 that used the three-second gust duration. This gust duration resulted in higher magnitudes of wind loads that ended up making the structures unnecessarily robust and uneconomical. Using the Eurocodes had the promise of achieving more economical designs because it used the 10-minute gust duration. The 10-minute gust duration resulted in typically lower magnitudes of wind loads than the three-second gust duration for the same wind speed. Kenya adopted the Eurocodes in September 2012 but had not yet developed its national annexes opting instead to use the UK National Annexes. The UK National Annexes were applicable to Kenya in some scenarios but not in others such as wind loading. The lack of the Kenya National Annexes led to difficulties in the adoption of the Eurocodes. This paper outlined a procedure in which the existing wind data given in three-second gusts could be converted to 10-minute wind speeds. Once converted, the method described in the UK National Annex could then be followed selectively to determine the wind load on a structure. Lastly, the paper recommended that wind data collected from 1977 to 2021 by the Kenya Meteorological Department be incorporated to the development of the wind map for the Kenya National Annex to KS EN 1991-1-4:2005.

Separating the Contributions in Localization Methods: A Technique to Enhance Identification of Damping Related Parameters

1999 ◽  
Author(s):  
Hervé Algrain ◽  
Calogero Conti ◽  
Pierre Dehombreux
Keyword(s):  
Finite Element ◽  
Model Updating ◽  
Element Model ◽  
Dynamic Responses ◽  
Finite Element Model Updating ◽  
Global Localization ◽  
Localization Method ◽  
The Family ◽  
Family Based ◽  
The Stability

Abstract Finite Element Model Updating has for objective to increase the correlation between the experimental dynamic responses of a structure and the predictions from a model. Among different initial choices, these procedures need to establish a set of representative parameters to be updated in which some are in real error and some are not. It is therefore important to select the correct properties that have to be updated to ensure that no marginal corrections are introduced. In this paper the standard localization criteria are presented and a technique to separate the global localization criteria in family-based criteria for damped structures is introduced. The methods are analyzed and applied to both numerical and experimental examples; a clear enhancement of the results is noticed using the family-based criteria. A simple way to qualify the stability of a localization method to noise is presented.

Parameter Sensitivity in Numerical Modelling of Ice-Structure Interaction With Cohesive Element Method

2016 ◽  
Author(s):  
Dianshi Feng ◽  
Sze Dai Pang ◽  
Jin Zhang
Keyword(s):  
Element Model ◽  
Offshore Structures ◽  
Parameter Sensitivity ◽  
The Arctic ◽  
Cohesive Element ◽  
Structure Interaction ◽  
Marine Structure ◽  
Ice Loads ◽  
The Stability ◽  
Element Method

The increasing marine activities in the Arctic has resulted in a growing demand for reliable structural designs in this region. Ice loads are a major concern to the designer of a marine structure in the arctic, and are often the principal factor that governs the structural design [Palmer and Croasdale, 2013]. With the rapid advancement in computational power, numerical method is becoming a useful tool for design of offshore structures subjected to ice actions. Cohesive element method (CEM), a method which has been widely utilized to simulate fracture in various materials ranging from metals to ceramics and composites as well as bi-material systems, has been recently applied to predict ice-structure interactions. Although it shows promising future for further applications, there are also some challenging issues like high mesh dependency, large variation in cohesive properties etc., yet to be resolved. In this study, a 3D finite element model with the use of CEM was developed in LS-DYNA for simulating ice-structure interaction. The stability of the model was investigated and a parameter sensitivity analysis was carried out for a better understanding of how each material parameter affects the simulation results.

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