الفهرس 
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Abstract
The present thesis is concerned with the development of rational and comprehensive constitutive SFRC modelsfor nonlinearfinite element analysis of planar structures subjected to static and seismic loads. A combined composite continuum and nonlinear fracture mechanics approach is used in joint with the existing expermintal results in order to develop the proposed constitutive laws and failure criteria for SFRC behavior under monotonic and cyclic loading conditions. The proposed models account for material nonlinearities in tension, compression and shear, SFRC cracking, steel fibers micro-failure and arresting mechanisms, SFRC fracture energy, strain softing and size dependency effect. Also, the stress-strain laws recongnize strength, stiffness and ductility changes due to biaxial stress state, cyclic loading-induced damage, confinement mechanisms associate with discrete steel fibers and hoops, shear transfer mechanisms in cracked SFRC and yielding and plasticity of reinforcing steel bars and stirrups. The constitutive laws are incorporated into a finite element computer program which has been employed to perform several vaildation and parametric studies of nonlinear response of SFRC plane structures under static and earthquake loading. Main emphasis is directed to study the seismic reponse of SFRC beam column joints.
A strain-induced orthotropic nonlinear elastic model is developed for simulating the biaxial behaviour of SFRC in compression and tension. Also, comprehensive uniaxial models are proposed and act as an integral part of the proposed biaxial model within the comcept of equivalent uniaxial strian necessary to develop the monotonic and cyclic stress-strain relations. Semi-empirical expressions are develop to predict the complete nonlinear stress-strain curves of unconfined and confined SFRC under uniaxial monotonic compression. The characteristic modeling parameters are derived as empirical functions of fiber reinforcing index and hoop confinement index. A fracture energy-based and size dependent tension model is developed for SFRC. Based on linear fracture mechanics semi-empirical relations are developed for SFRC. Based on nonliear fracture mechanics stress-crack width relations are developed for tension softening branch, post-cracking strength, stress-crack width relation, fracuture energy and ultimate strain.