Papers by Keyword: Fiber Model

Abstract: For engineering practice purpose, the macroscopic model capable of simulating the main characteristics of nonlinear behavior is desirable to reduce computational efforts in nonlinear structural analysis. Several different types of macroscopic models for shear walls have been developed. The shear wall element used in the commercial program PERFORM-3D is one types of macroscopic models for reinforced concrete shear walls. The application of PERFORM-3D in the nonlinear static analysis of reinforced concrete shear walls is introduced in this study. The selection of constitutive models and the determination of related parameters of the constituent material are presented in detail. The applicability of the shear wall element is verified by numerical simulation on three reinforced concrete shear wall specimens under cyclic loading. The comparison between the numerical analysis and test results leads to the conclusion that the shear wall element with appropriate constitutive models can capture the nonlinear behavior of reinforced concrete shear wall well and be conveniently applied in engineering practice.

Abstract: This paper used the OpenSees^[1] to simulate an externally prestressed composite beam, by contrasting the experimental results to explore the factors that affect the accuracy of the numerical simulation. The different numerical models are constituted with the different material constitutive models in this paper, with the different section fiber division and other factors. We can consider the method of a part of combination beam section which is connecting with shear rivets. The results show that the different concrete constitutive model and the hardening of the steel constitutive model are the important factors of the accuracy of model, and the Gaussian integration points have 3~5 are bitterly for the simulate mode. This study can provide a theoretical basis for the externally prestressed composite beam’s bending behavior of steel beam section’s numerical simulation with the fiber model.

Abstract: Using flexibility-based finite element method based on fiber model, several experiments of reinforced concrete specially shaped columns under cyclic loading which cross section is ‘L’, ‘T’ and ‘+’ shape with different longitudinal reinforcement and hoop reinforcement have been simulated, and the seismic behavior of columns such as strength, ductility and energy dissipation are analyzed. Results from the analytical study indicate that: 1) ductility of the column increases as quantity of hoop reinforcement increases. 2) strength capacity of the column increase linearly as ratio of longitudinal reinforcement increase, but is not seriously affected by hoop reinforcement; 3) energy dissipation capacity of the column is not significantly affected by hoop and longitudinal reinforcement, particularly in slightly nonlinear range.

Abstract: Reinforced concrete core walls with good anti-side rigidity and spatial rigidity is used widely in high-rise buildings. Elasto-plastic static analysis of core walls are be realized by the program CANNY based on the theory of fiber model. Compared with the tests, Results from the simulation anlysis match well with those from the tests. The influence of axial compression ratio and height-width ratio on the bearing capacity and deformation of core walls are analyzed systemically. It is shown that the fiber model is available and successful for the numerical simulation of core walls. The axial compression ratio has distinct affect on the elastic and inelastic behavior of RC core walls. The ratio of height to width not only has effect on the bearing capacity and deformation performance, but also changes the failure mode of RC core walls. The numerical results confirmed the accuracy of this analysis procedure in representing the nonlinear behavior of core walls.

Abstract: In this paper, to verify the effectiveness and reliability of nonlinear numerical simulation based fiber model, two computer programs (CANNY 99 and IDARC-2D), in which shear wall elements were respectively simplified by fiber model and equivalent beam model, were adopted to perform the numerical simulations of 10 times shaking table tests of a nine story 1:6 scale frame-shear wall building model in this paper. Analysis model including beam, column and wall element in CANNY 99 is elaborated in detail. Test results are compared with simulation results in some aspects such as natural frequency, time history responses, and peak value responses. Results demonstrate that fiber model and Equivalent beam model can simulate the elastic-plastic earthquake response of R.C. wall structures very well.

Abstract: Base on the elastic-plastic analytical theory, an elastic-plastic time-history analysis of self-anchored cable-stayed suspension bridge, which engineering background is Dalian Gulf Cross-sea Bridge program, is performed by using general finite element software Midas/Civil. The material nonlinearity of structure is considered with reinforcement concrete fiber model, and distributed hinge type is adopted to simulate for plastic hinge. Compared with the results of an elastic time-history analysis, it is shown that for the structure into the elastic-plastic stage, because of the production of plastic hinge, the input seismic energy is dissipated partially, and the internal forces of structural elements are reduced. The bending moments and axial forces occur mainly in the main tower root. Furthermore, the rotation properties of the plastic hinge causes displacement increasing of certain parts of the structure, which assumes mainly the vertical displacement present on the top of main tower and the main beam. In conclusion, it is proposed that caging devices are set in the design.

Abstract: Under the excitation of large earthquake, structures enter into high nonlinear stage. Currently, Opensees, Perform-3d and Canny are used as the most popular nonlinear analysis procedures. The fiber model will be introduced firstly and the nonlinear analysis models in Canny are explained in detail. Then Canny2007 is used to conduct nonlinear time history analysis on a heavily damaged frame structure with interlayer in Dujiangyan during Wenchuan Earthquake. Analysis shows that the maximum inter-story drift appears between the interlayer and its upper layer, and the heavy damage agrees well with the results of damage investigation. By comparing the damage extent of frame structures with or without interlayer, it reveals that the seismic performance of RC frame structures without interlayer is obviously better than that of ones with interlayer.

Abstract: Because the SRC (steel reinforced concrete) structures fully combine the advantages of two materials i.e. steel and concrete they had been widely used in high-rise buildings. Completely study the moment-curvature relation of this kind of member is essential to a nonlinear analysis of this type of structures. The fiber model method based on the section discretion directly reflect the restoring characteristics of the member though the stress-strain relationship of steel and concrete. It can be applied to analyze section with any configuration. In this paper, the hysteretic moment-curvature relation of SRC column is analyzed by coding and verified by available test result. And finally several factors influenced on the M-Фrelation is discussed.