Abstract: Water is very important as one of the main factors of human life for drinking as well as purposes related to human life and human nature. Increasing demand of water caused the emerging science of dam engineering and also construction large dams for agricultural purposes, drinking, industry and also flood control, power generation, recreational and tourist use and etc. Large dams can remarkably effect on the environment as a non-stabilizing factor in nature in various stages of construction, operation and end of life by stopping the flow of the river and stored water. However, if the environment cannot tolerate this instability, the results of the destruction of this structure will gradually rise and the objective of dam construction will be lost. The reality is that, the environmental effects are not considered fully and completely for the most dams have been constructed in Iran. In this paper, we will review the environmental impact of construction large dams on some rivers in the cou

• Publication Date: 05-May-2013
• DOI: 10.15224/978-981-07-6261-2-66
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Abstract: A dynamic analysis of axially loaded Timoshenko beams with intermediate fixities is presented. The underwater part of a craft is modeled as a flexible beam, which rises out and slams against the water at a large vertical velocity, causing highly localized hydrodynamic impact pressure moving at high velocities across the beam, setting it into high-frequency vibrations. The beam natural frequencies depend on the slenderness ratio, axial load, and end fixities. Increasing the axial tension and/or end fixity increases the natural frequencies, which are generated through Eigen analysis.Next, normal mode summation is used to analyze the impact-induced vibration response, which is generated for various impact speeds, deadrise angles, end fixities, axial loads, and slenderness ratios of the beam. A parametric study is done to predict the maximum dynamic stresses on the structure. The pressure is assumed to act at the equilibrium position. The aim is to study the dynamic stress configurations a

• Publication Date: 05-May-2013
• DOI: 10.15224/978-981-07-6261-2-67
• Views: 0
• Downloads: 0