Research Of The Structural Behavior Of The Steel Struss-Concrete Composite Beam

The steel truss-concrete composite beam is a new kind of composite structure, in which the concrete deck slab and the steel co-act togther, has come into widly use in high-speed railway by European, American countries and Japan because it has so many advantages such as big stiffness, low building height, good integrity, slight noises and well dynamic behavior in train driving. Along with the speed up of the existing railway and the rapid construction of high-speed railway this type bridge must be widly used in China too So this thesis propsoses to study the structural behavior of steel truss-concrete composite beam, it is significant.This thesis introduces the application and current research of the steel truss-concrete composite beam at home and abroad, steel truss form and characteristics, type of shear connectors and bearing capacity calculation method of the stud, the different combing condition of concrete slab with stringer and floorbeam of steel truss.In order to study the structural behavior of the through multi-crossbeam floor system simply-supported steel truss-concrete beam, the author uses of spare finite element calculation analysis for a proposed 108m span. The main contents are follows:1. Reasearch the structural behavior of the structure, the axial force distribution between the lower boom and the deck, the stress distribution of concrete bridge panel under the lst-stage dead load,2nd-stage dead load and live load including double-track symmetry live loads,and the natural vibration characteristics of the structure.2. Reasearch the displacement condition of the load side and unload side lower boom, the shear distribution between the two nodes of the floorbeam, the torsion of the main steel truss under the single-track live load.3. Reasearch the load structure stress condition and its distribution of the concrete bridge deck under three different temperature load which can reflect the condition of sudden cooling, sunshine influence and temperature gradient.4. The degree of shear connection and the stiffness of floorbeam have great effect on the stress of the steel truss-concrete composite beam, this thesis also made some study on lower boom displacement of the steel truss, internal forces and the stress distribution of concrete bridge deck under double-track symmetry live loads with different degree of shear connection and stiffness of floorbeam.The results may be taken as reference for the design of steel truss-concrete composite beam.