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Characteristics And Design Of Downburst Loaded Transmission Lines, Mohamed Mohamed Salah El-Din Darwish

Digitized Theses

During the past years, many electrical transmission lines have failed during downbursts. This thesis is part of a research program aimed to understand the behaviour of transmission lines under localized winds. The first part of the thesis assesses the dynamic behaviour of the conductors under downburst loading. A non-linear numerical model is utilized to predict the natural frequencies and mode shapes of the conductors at various loading stages. A turbulence signal is added to the mean component of the downburst wind field previously evaluated from a CFD analysis. Dynamic analysis is performed using various downburst configurations.

The second part of …

Optimum Design Of Cable-Stayed Bridges, Mahmoud M. Hassan

Digitized Theses

Owing to their excellent structural characteristics, aesthetic appearance, low maintenance cost, and efficient use of structural materials, cable-stayed bridges have gained much popularity in recent decades. Stay cables of a cable stayed bridge are post-tensioned to counteract the effect of the bridge dead load. The solution for an optimum distribution of post-tensioning cable forces is considered one of the most important and difficult tasks in the design of cable-stayed bridges. A novel approach that utilizes the finite element method, B-spline curves, and real coded genetic algorithm to determine the global optimum post-tensioning cable forces is developed. The effect of geometric …