

Type of Document Dissertation Author Janajreh, Isam Mustafa II Author's Email Address janajreh@vt.edu URN etd-32198-124554 Title Wavelet Analysis of Extreme Wind Loads on Low-Rise Structures Degree Doctor of Philosophy Department Engineering Mechanics Advisory Committee
Advisor Name Title Prof. Muhammad R. Hajj Committee Chair Prof. Dean T. Mook Committee Member Prof. Henry W. Tieleman Committee Member Prof. Robert E. Heller Committee Member Prof. Saad A. Ragab Committee Member Prof. Werner Kohler Committee Member Keywords
- wind loads
- pressure coefficients
- turbulence intensities
- turbulence scales
- wavelets
- higher-order statistics
- intermittency
Date of Defense 1998-01-29 Availability unrestricted Abstract Over the past thirty years, extensive research has been conducted with the objective of reducing wind damage to structures.Wind tunnel simulations of wind loads have been the major source of building codes.
However,
a simple comparison of pressure coefficients measured in wind tunnel simulations with full-scale measurements show that the simulations, in general, underpredict
extreme negative pressure coefficients.
One obvious reason is the lack of consensus on wind tunnel simulation parameters.
The wind in the atmospheric surface layer is highly turbulent.
In simulating wind loads on structures, one needs to simulate the turbulent character besides satisfying geometric and dynamic
similitudes.
Some turbulence parameters that have been considered in many simulations include, turbulence intensities, integral length scales, surface
roughness, and frequency spectrum.
One problem with these parameters is that they are time varying in the atmospheric boundary layer
and their
averaged value, usually considered in the wind tunnel simulations, cannot be used to simulate pressure peaks.
In this work, we show how wavelet analysis and time-scale representation can be
used to establish an intermittency factor that characterizes energetic turbulence events in the atmospheric flows. Moreover, we relate these events to the occurrence of extreme negative peak pressures.
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