In this article we will discuss about how to measure fluctuating pressure caused my wind movements. Pressure Transducers: The basic requirement of a pressure transducer is a device which accurately transforms a pressure difference to an electrical voltage. Two basic phenomena are used: (i) The change in resistance of conducting or semiconducting element as it is strained; and (ii) The [...]
In this article we will discuss about how to estimate extreme wind speeds without regard to direction. To within a constant dimensional factor, the time series Wj is the same as the time series maxi [vJ(θl)] = Vj (j = 1,2, . . ,N). Extreme idealized wind loads can therefore be obtained from estimates of the extreme variate V Inferred [...]
In this article we will discuss about the estimates of various types of wind speeds. Estimates of Extreme Wind Speeds from Short Records: A procedure for estimating extreme wind speeds without regard for direction at locations where long-term data are not available was reported by Simiu et al. (1982) and Grigoriu (1984). The method, whose applicability was tested for 36 [...]
In this article we will discuss about the relation between extreme wind speeds and extreme wind loads. Assume that the wind velocity is known at a particular location and elevation near a structure, where it is unaffected by any obstructions and is therefore indicative of the ambient wind environment. The wind pressure at a point on the building surface, or [...]
This article is concerned with measuring the dynamic properties of prototype structures, especially those characteristics which are important for calculating structural response to wind loading. Introduction to the Dynamic Characteristics of Prototype Structures: In the design of a tall building or a large bridge, the evaluation of structural response to the design wind load may be important both for serviceability [...]
In this article we will discuss about:- 1. Introduction to the Physical Modelling of ABL 2. Primary Features of the Atmospheric Boundary Layer (ABL) 3. Similarity Criteria 4. The Meteorological Wind Tunnel (MWT). Introduction to the Physical Modelling of ABL: Efforts to determine wind effects on objects and dispersion of air pollutants using small-scale models in air flows generated by [...]
In this article we will discuss about the developments in the aeroelasticity of bridges. For over 100 years prior to the pivotal Tacoma Narrows bridge disaster of 1940 flexible bridges had been noticeably disturbed and some severely damaged by the wind. However, the late 1930's and early 1940's witnessed introduction of new consciousness and appreciation of what kinds of forces [...]
In a typical city environment where many tall buildings and structures are grouped closely together, the proximity of one building to another can influence the flow field around and the wind forces acting on the buildings. Such interference effects are particularly marked for a group of identical structures such as a line of chimneys. The interactions of neighbouring tall buildings, [...]
In this article we will discuss about:- 1. Introduction to Wind Loads on Low Buildings 2. Historical Development of Wind Loads on Low Buildings 3. Codes and Standards/Full-Scale Measurements 4. Computational Evaluation of Wind Pressures. Introduction to Wind Loads on Low Buildings: Wind loads on low buildings have not received the attention they deserve when the large investment in such [...]
Regarding wind loading of low buildings the following overall considerations are appropriate: i. Atmospheric simulation requirements are generally similar to those for tall buildings. ii. There is a large variety of low building geometries. iii. Special tests are usually unjustifiable economically and hence there is more reliance on generic tests. iv. Aspects special to low buildings are due to their [...]