Nonlinear Finite Element Analysis Of Reinforce-concrete Frame Structure To Resist Progressive Collapse

Reinforce-concrete frame structure is the most widely used structure. The key to thestudy is whether structure member has enough ductility and can form new powertransmission way after its vertical component failure. Using finite element analysissoftware ADINA set up analysis models. Nonlinear M beam that could describereinforced concrete structure exactly is used for set up model’s constitutive relation. Withthe consideration of nonlinear of structure system, model is set up about frame beam,plane frame and three-dimensional frame.The finite element model, which is set up with5different kinds of reinforcing bars,analyzed by Pull-down method with the comparison of finite element analysis results andtest results of frame beam which is under static load to improve its correctness. Theanalyzed result shows that the limitation of load that beam can bear improve continuouslywith the increase of the longitudinal reinforcement ratio and then improve frame collapseresistant capacity.Curvature beam is used to set up finite element analysis model about the plane frameand the three-dimensional frame which lost their Bottom side column until. Gettingstructure Pull-down（P~δ）curve with the Pull-down method and then use the limitload that get from the calculation about structure under sudden load as the evaluatingindicator to judge Vertical continuous collapse whether happened to the structure. Theanalyzed result shows that: the3-D frame will not be progressively collapse but the2-Dframe will, and they are set up with the same constitutive relation. Therefore, space effectof3D framework can not be ignored.