Abstract
Wind has a great impact on civil structures. It is considered a dynamic and random phenomena and it plays an important role in the design of tall structures. Existing buildings with certain height must resist wind effect. Many researchers have developed theories and schemes that consider more thoroughly wind components and the influence of its turbulence on buildings. It is known that any structure inherently dissipates and absorbs energy due to external loads thanks to its inherent damping. In order to improve this capacity and limit structural damage, fluid viscous dampers are commonly used for structural protection; they have confirmed their efficiency and reliability. Many researchers have investigated their effect by inserting them in the structure; some of the optimization methods for the design of these dampers previously used will be discussed. Finally, an effective method for optimal design of additional dampers will be illustrated by an example and discussion.
TopWind Loads And Simulation
Wind have a great impact on civil structures and their design, a satisfactory representation of wind load must deal with several random parameters i.e. stochastic process, as wind climate, terrain roughness and structures geometry. These parameters require the use of statistical methods in order to adapt them to each studied structure.
Wind load vary in time and space and over the height and surface of structures, and it is subjected to two types of aerodynamic forces: drag forces i.e. along wind, that acts on the direction of the mean flow, and lift force i.e. across-wind, which acts perpendicularly to that direction (Simiu & Scanlan, 1986). The use of codes and standards is of utmost importance in the design phase, since it simplifies widely the complex nature of wind. However, it is crucial to understand the methodology behind the rules and clauses in order to make good use of the codes.
Key Terms in this Chapter
Correlation: Dependence or association in any statistical relationship, whether causal or not, between two random variables.
Fast Fourier Transform: ( FFT): Is an algorithm that samples a signal over a period of time and divides it into its frequency components used to improve the computational efficiency.
Variance: In probability theory, it is the expectation of the squared deviation of a random variable from its mean, and can be estimated as the area of the PSD graph (response).
Ergodicity: An ergodic process is a process which its statistical properties can be deduced from a single, sufficiently long, random sample of the process.
Stochastic Process: A stochastic or random process is a phenomenon usually defined as a collection of random variables.