Flexural Behavior Of Steel-concrete Composite Members

Nowadays, reinforced concrete structures are widely used in nuclear powerplants. However, reinforced concrete structures possess low ductility and energydissipation capacity. Under heavy earthquake load, they easily failed with brittlephenomenon. Moreover, the external concrete of containment is damaged seriouslyunder the influence of environment such as the rain, sun, etc. The cracking or peelingof concrete reduces the permeability resistance of concrete. To make nuclear powermore competitive against other energy sources, improving its earthquake resistance,reducing the construction time, thus reducing the cost, certainly is one of the means toachieve this goal. Recently, the steel plate concrete (SC) module has been proposed inthe AP1000and US-APWR nuclear power plants to improve safety and reduce theconstruction time. However, the SC module is not covered in any international codesand standards. The analytical method for analyzing SC modules under the monotonicloads or seismic loads is, however, not available now. Therefore, there is an urgentneed for an analytical method to predict the behavior of SC module during the seismicloads. In order to understand the behavior of SC structures, we need to firstunderstand the flexural and shear behavior of SC beams. In this paper, the finiteelement software Abaqus is used to develop the finite element model. The static andcyclic behavior of SC beams under bending moment is studied. The main contents areas follows:(1) Three-dimensional finite element model (FEM) is developed using thecommercial finite element software ABAQUS. In this model, the strain-stressrelationship of the steel and concrete are determined. The element type of steel plate,concrete and shear connectors are determined. The existing experimental results areused to verify the accuracy of the model in this paper.(2) The static bending performance of steel-concrete composite components isstudied. The mechanical properties, including bearing capacity and ductility of thecomposite component, are analyzed. The effects of parameters, such as steel platethickness, steel yield strength, concrete compressive strength, spacing and diameter ofshear, etc, on the static performance of components are investigated. The calculationformula of flexural bearing capacity of the steel-concrete composite members is proposed.(3) The hysteretic behavior of the steel-concrete composite components isstudied. The energy dissipation ability evaluation indexes of component aredetermined. The effects of parameters, such as steel plate thickness, steel yieldstrength, concrete compressive strength, etc, on the hysteresis curves are analyzed.