Waleed Abdulmalik Thanoon

Influence of torsion on the inelastic response of three-dimensional r.c. frames

A three-dimensional reinforced concrete framed building was modelled using finite element method. Two types of elements, the beam-column element and flat shell element were used for modelling the frame and floor slabs, respectively. A computer program has been developed for the analysis of 3D framed building by integrating the finite element and stiffness method. The lumped inelasticity model with three-dimensional point hinges at the ends of the beam-column element was implemented. A yield surface for a reinforced section of the member subjected to simultaneous actions of biaxial bending, torsion and axial forces was evolved. The developed yield surface integrated with the theory of plasticity was used to develop a suitable procedure for inelastic analysis of three-dimensional problems with the floor slab assumed to remain elastic throughout the analysis. The inelastic procedure is able to predict the sequential formation of plastic hinges in the frame members and the continuous deterioration of the stiffness of the frame. A single storey one bay reinforced concrete space frame was analysed for twist loading to study the inelastic response of the reinforced concrete frame. The results indicate that, the consideration of torsion in defining the yielding surface plays a significant role in the inelastic behaviour and estimation of failure load for reinforced concrete frames under torsional loading.

Inelastic Seismic Response of RC Building with Control System

Conventional buildings are mainly designed based on elastic analysis of structures subjected to moderate earthquakes. In this case, the seismic forces are much smaller than the forces introduced by strong ground motions with the considered structural behavior going to nonlinear response during these severe earthquakes. Improving the earthquake resistance of reinforced concrete buildings using a variety of earthquake energy dissipation systems has received considerable attention in recent years by civil engineers. In the present study, a nonlinear computational scheme was developed to predict the complete nonlinear dynamic response of reinforced concrete framed buildings equipped with viscous damper device subjected to earthquake excitation. A finite element program code is developed based on the nonlinear analysis procedure of reinforced concrete buildings equipped with viscous damper devices and a two dimensional, five story models of RC buildings subjected to earthquake were analyzed. Result of nonlinear analysis of RC buildings which furnished by viscous dampers indicated that using of viscous dampers effectively reduced the damages occurring in the building and structural motion during severe earthquakes.

Enhancements in idealized capacity curve generation for reinforced concrete regular framed structures subjected to seismic loading

Abstract The designing of R/C framed structures subjected to seismic excitation generally is performed by linear elastic method, while current trend of codes of practice is moving toward increasing emphasis on evaluating the structures using non‐linear static pushover (NSP) approaches. Recently, several NSP approaches, with varying degree of vigor and success, have been proposed. In this study, initially a comparative study has been made among different non‐linear static methods for adopting the most suitable method of extracting the capacity curve of R/C framed structures. Then, a program was developed to overcome the difficulties of graphical iterative procedure of idealization proposed by FEMA‐356. Subsequently, the comparative tool, which is a combination of the detected superior NSP method and the developed program, was used to investigate the effects of significant structural variables on idealized parameters of capacity curves of population of R/C framed structures. Eventually, the applicability of...

3 Dimensional Damper Element For Reinforced Concrete Frames

This paper describes the development of a numerical finite element algorithm used for the analysis of reinforced concrete structure equipped with shakes energy absorbing device subjected to earthquake excitation. For this purpose a finite element program code for analysis of reinforced concrete frame buildings is developed. The performance of developed program code is evaluated by analyzing of two reinforced concrete frame buildings model. The results are show that using damper device as seismic energy dissipation system effectively can reduce the structural response of framed structure during earthquake occurrence.