الفهرس 
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Abstract
For conventional analysis and design of steel framed structures, the actual response of the beam to column connections is simplified to either or pin-connected behaviour.Although the adoption of such idealized performance simplified the analysis and design process, the predicted response of the idealized structure may be quite unrealistic compared to that for the actual structue. This is because most of most meam to column connections used in practical steel framed structures actually exhibit semi-rigid deformation behaviour can contribute substantially to overal l structural deformation and to internal force redistribution in the members of the structure. Evidently, the neglect of real connection behaviour may lead to unrealisti predictions of the stiffness and strength of steel structures. Thus, it is necessary to account for the effect of connection flexibility when designing such structures if realistic and econpmical designs required to be found.
The present study has established a mathematical and numerical model of an effecient computer-based method for the study of dynamic stability of steel frameworks accounting for the behaviour of semi-rigid connections.The study begins with the mathematical modeling of the semi-rigid beam to column connections and base connections. The members are sized using sandard steel sections and the connections are selected from the database of conventional connections.The nonlinear moment-rotation behaviour of the beam to column connections is represented by four-parameters power model. The base connections are represented by four-parameter exponential model. Then the dynamic stabilityb functions of semi-rigidly connected elements under free and forced vibration conditions are evaluated.The pulsating loads due to axial variable loads that can be represented by a harmonic function of approaches of analysis have been used in the application. The different approaches of analysis have been used in the application. The first approach is an elastic analysis based on geometric perfection and original stiffness of the frame connections. The second approach is an elastic-plastic hinge analysis including the effect of nonlinear connection behaviour. The result of the study show that proposed method of analysis realistically accounts for the structural behavior than the tradional methods. It can be concluded that the study is practiculrly important due to the basic understanding of the dynamic behaviourv of semi -rigidly connected structures besides the lack of design code criteria. Yet littele puplished information are available to help the strucrural analyst to deal realistically with dynamicstability problems fie for semi-rigidly connected structures. The present study attempts to answer some questions that help in explaining the dynamic behavioue of structure taking into accounts the real connention behaviour.