الفهرس 
chapter 1Only 14 pages are availabe for public view
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Abstract
Frames compris~l of steel, reinforced concrete, and ~omj10site member are emerging as efficient alternatives to traditional steel or reinforced concrete systems. Composite structures are defined as structures built from self-carrying sub-elements connected by shear connectors to form an interacting unit. Among many examples of the com1111Site structures are the steel-concrete beams These beams are widely used for floor constructions in buildings and bridges. Generally, the structures contain composite members are more economic after engineering structurt’s became more light-weighted and aspects of safety and durability rose in importance, the dynamic effect on building structures caused by seismic actions have become increasingly important for their analysis and design. Modern computing technologie.s rapidly enable the practical application of nonlinear static and dynamic analysis in design. Therefore, there are increasing needs for accurate and efficient inelastic analysis 11rocedure, which is, in the present I research, the direct stiffness method ’ ..\numerical model based on the boundary sectional model is developed in order to study the nonlinear dynamic behavior of composite, R.C, and steel structures. The model predicts the proru~rtie!i of the cross section as well as its inte•·nal force~ which are calculated from the strains and stresses. This model is based on the numerical integration of material point stiffness as well as the stresses along the boundaries of the cross section in order to obtain the 011erties and internal forces, res11ectively. !’lumerical integration and mdhods such as Newton-Cotes formulas, Gauss Quadratures, and Gauss-Lohatto methods are examined with the boundary line integration. This method proves its accuracy with all methods of integration over the commonly used fiber section model In addition, a new numerical iterative technique is proposed in order to lll”edict the nonlinear moment-curvature relationship for composite, RC. and steel cross sections. The moment and axial force are computed at two selected 11oints and the iterative solution is carried out to find the moment at certain curvature and axial force values. This technique employs powerful mathematical technique which combines both of the Bisection and the Successive Convergence methods. The 11r0posed technitiUe is tested and shows high accuracy and speed comparing with other techniques founded in the literature The developed cross section model is extended to the structural level to study both linear and nonlinen dynamic behavior of composite, R.C, and steel frames by using finite element method The strain-displacement relationships of planar frame element are derived. An incremental iterative procedure based on Bergan’s method is used to trace the nonlinear force deformation relationship as well as the Newmark constant acceleration method which is used to 11roduce the numerical integration of the time-history dynamic analysis An efficient computer program for linear and nonlinear static and dynamic analyses of plane frames has been developed. Each single item of the program was verified using a variety of analysis tv11es. The com1JUter 11rogram has interesting features such as graphical user interface (GUI), gra11hical out1mt of the analysis results, ami animation of dynamic response of frames Final!~, some correlative studies are 1nesented to describe the nonlinear response of composite frames subjected to seismic actions. The case study frames are selected in such wa~’ to stud~· six main 11arameters. These 11arameters are: effect of damping, <’ffect of construction material ty11e, 1 ! effect of number of stories, effect of Ji;round acceleration levels. and the effect of variation of column I stiffness. The case study frames a•·e subjected to one of well-known ground motion records one. at a j time. Some im rtant conclusions are derived from the results.