Shahsavar V.L., Tofighi S.
UNCERTAINTIES ON FREE VIBRATION OF INHOMOGENEOUS ORTHOTROPIC REINFORCED CONCRETE PLATES ^{[№ 9 ' 2014]}
Analyzing the nearly collapsed and broken structures gives a good insight in the possible architectural and engineering design mistakes, faults in the detailing and the mismanagement of the construction by the building contractors. Harmful vibration effects of construction operations occur frequently. The background reviews have demonstrated that the problem of vibration serviceability of long-span concrete floors in buildings is complex and interdisciplinary in nature. In public buildings, floor vibration control is required due to meet Serviceability Limit States that ensure comfort of users of a building. In industrial buildings, machines are often placed on floors. Machines generate vibrations of various frequencies which are transferred to supporting constructions. Precision machines require a stable floor with defined and known dynamic characteristics. In recent years there has been increasing interest in the motion of elastic bodies whose material properties (density, elastic modules, etc.) are not constant, but vary with position, perhaps in a random manner. Concrete is a non-homogeneous and anisotropic material. Modeling the mechanical behavior of Reinforced Concrete (RC) is still one of the most difficult challenges in the field of structural engineering. One of the several methods for determining of the dynamic modulus of elasticity of engineering materials is the vibration frequency procedure. In this method, the required variables except modulus of elasticity accurately and certainty determined. In this research, uncertainly analysis of free vibration of inhomogeneous orthotropic reinforced concrete plates has been investigated. Due to the numerous outputs obtained, software package has been written in Matlab and analysis on the data and drawing related charts have been done.