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 [...]
The below mentioned article will guide you about how to approach to full model wind tunnel testing. Introduction to Full Model Wind Tunnel Testing: Recent needs of going for the record to stretch the spans much farther are hardly competitive in the construction of suspension bridges as well as cable-stayed bridges. To provide longer, uninterrupted spans over terrain the structural [...]
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 [...]
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 [...]
Comparisons of wind-tunnel and field measurements are essential for checking the validity of modelling criteria and procedures. Micrometeorological data used for the subsequent comparisons are primarily from measurements in the ASL. Stably stratified flow over a smooth surface with only a saw-tooth trip at the test-section entrance was investigated in the MWT by Arya et al (1969). A graph showing [...]
In this article we will discuss about the primary features and historical development of bluff body aerodynamics. Primary Features of Bluff Body Aerodynamics: The term "bluff body aerodynamics" is intended to cover the study of flow fields around, and force on, a body from which boundary layers are separating to form unsteady vortex flows in a wake region. The great [...]
In this article we will discuss about:- 1. Introduction to Strong Winds 2. Historical Perspective of Strong Winds 3. High Wind Speeds 4. Description of the Atmospheric Boundary Layer 5. The Structure of Winds and Its Measurement 6. Description of Statistics 7. Some Significant Measurements 8. Conclusion. Introduction to Strong Winds: The occurrence of strong winds, to their measurement and [...]
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 [...]