The Research On Mechanics Capability Of Steel-Concrete Composite Beams Under Negative Moment

The steel-concrete composite beam bridge has wide applitation in urban road of our coutry.The new type structure in which the steel and the concrete are integrated by connectors to take advantage of the respective properties of tention and compression.Though composite beams have been applied and researched extensively,it is not enough in investigating the mechanical behaviors under negative moment.This research paper comprehensively summarize the state of the art of the steel-concrete composite beam.The research was focused on the behavior of composite beams under negative moment.based on SPECIFICATIONS FOR DESIGN OF STEEL STRUCTURE AND TIMBER STRUCTURE HIGHWAY BRIDGES AND CULVERTS(JTJ 025-86), consulted the new edition STEEL STRUCTURE DESIGHN SPECIFICATION(GB 50017-2003) and correlative literature,The academic design methods to composite beams have been illustrated detailedly.The nonlinear transient analysis was performed by using ANSYSlO.O.The FEM model was set up by consider slip effect and ignore slip effect respectively.The analysis was used to analyze load-deformation behavior of composite beams.The effect of slip toward to composite beam was illustrated and the relationship between longitudinal reinforcement ratio and ultimate loading capacity of the beam was conducted.Through the research mechanics capability of steel-concrete composite beams under negative moment,the distributing rule of positive stress,vertical shearing strength,strain,the relation between bending moment and shearing force,the rule of bending moment new distributing under negative moment was described and destroy mechanism was found.Through the FEM analysis,several conclusions were gainedThe study results may serve as references for similar engineering projects,and designer canalso benefit from the theory and algorithm introduced in this paper.