Study on shear capacity of prestressed composite joints with concrete-encased CFST columns

Through assuming reasonable constitutive relation of materials, finite element analysis (FEA) models of joints consisting of prestressed concrete-encased steel beams and concrete-encased concrete filled steel tube (CFST) columns were established by soft ABAQUS, and the simulated results were compared with tested ones. On this basis, the nonlinear analysis on the total loading process was conducted, and the stress variation of concrete, profile steel skeleton, steel bar skeleton, and prestressing tendons were observed at yield, peak, and ultimate loads; the influence of axial compressive ratio, steel tube ratio, stirrup ratio, and prestressing level on lateral load-displacement curves at column top and shear force-shear angle in joint core were investigated, and the shear capacity formulae of joint core were developed. It could be concluded that, the lateral peak loads and shear capacity could be improved with the increase of axial compressive ratio, steel tube ratio, stirrup ratio, and prestressing levels in varying degrees, and the ductility of joints will reduce with the increase of axial compressive ratio. Additionally, the shear capacity calculated by proposed practical formula was a little lower than FEA results, which could keep the joints safety and could be used in engineering design.

Experimental study on seismic performance of frame flat columns with high axial compression ratio

When the lateral stiffness of the frame flat column is relatively small, the strength of the frame flat column is not enough to resist the large horizontal earthquake force and seriously deformed, which leads to the structure fail and could not work normally. In order to study the bearing capacity and the deformation capacity, experiments of three specimens of high axial compressive ratio under frequency cyclic loading were conducted, in which the failure process were observed in detail and the failure mechanism of the specimens were researched, the failure type, the hysteretic characteristic were studied, and the effect of the axial compressive ratio, the ties type and the stirrup ratio on the ductility of the members were analysed.

Influence of Axial Compression Ratio on Seismic Behavior of Reactive Powder Concrete (RPC) Beam-Column Joints

To explore the influence of axial compressive ratio on seismic behavior of reactive powder concrete(RPC) beam-column joints,this paper carry out RPC beam-column joints nonlinear finite element analysis,using software ABAQUS.The effect of different axial compression ratio on the ductility,energy dissipation capacity and bearing capacity are studied,based on hysteretic curves and skeleton curves of the components.The results show that,with the increase of axial compression ratio,skeleton curves of the components tend to be steep when the vertical load of beam ends exceed the peak point.The ultimate bearing capacity of the components are improved with the increasing of axial compression ratio which is less then 0.6,while the ultimate bearing capacity show a opposite trend when the axial compressive ratio exceed 0.6.

Non-Linear Numerical Simulation on Mechanical Behaviour of Steel Reinforced Concrete (SRC) Columns

In order to study the mechanics properties to of concrete columns with embedded steel, analysis models of SRC columns are established by using finite element software ABAQUS. Firstly, in order to validate the rationality of the analytical model, the test specimens are modeled, the results obtained from the finite element and experimental analyses are compared to each other, it is found that the finite element behavior indicates a good agreement with the experimental behavior. Furthermore, the ductility and ultimate capacity of SRC columns are studied with the changes of steel bone ratio and the axial compressive ratio. Analytical results demonstrate that embedded steel improves the ductility of SRC columns with large axial compressive ratio and steel bone ratios have obvious effect on ductility and ultimate capacity of SRC columns. The study results have some value on the design and application of the SRC columns.

Research on Method of Non-Linear Static Pushover Analysis and Influential Mechanism of Displacement Ductility of Single Pile

In this article, the distribution of plastic hinge model is adopted to simulate the elastic and plastic of pile body, p-y curve is used to simulate resistance of pile foundation soil. We do static non-linear pushover analysis of the single pile of pile foundations, and research the influence of the axial compressive ratio η of pile shaft, longitudinal reinforcement rate ρ of section, stirrup ratio µof section and shear strength C of foundation soil to the system-interaction of pile and soil. The result shows that axial compressive ratio of pile shaft has a significant influence on horizontal limit bearing capacity and the displacement ductility of the system. With the increase of the axial compressive ratio, system of the displacement ductility reduces gradually, but the limit bearing capacity increases gradually. Under a horizontal load, the order and the mechanism of plastic hinge are obviously different because of different axial compressive ratio of pile shaft，This analysis method may further provide a reference for nonlinear seismic analysis of pile bents.

Research on Behavior of Ultra-High Toughness Cementitious Composites Reinforced Frame Joints

In this article, through the seismic experimental analysis for six frame joints of ultra-high toughness cementitious composites, the load-carrying capacity, hysteretic behavior, energy dissipation and ductility of new joints are studied under different axial compressive ratio and the stirrups space. The experimental results show that the UHTCC joints have higher anti-cracking capacity and shear ductility. The UHTCC can reduce or even eliminate the amount of shear stirrups of the joint core. According to the analysis for the experiments, a theoretical calculating formula of shearing capacity is presented, whose calculating results agree well with the experimental results.