Torsion Experiment And Analysis On The New Type Of Steel-encased Concrete Composite Beams

Based on the analysis of some problems about the common steel-concrete composite beam, this article puts forward a new type of steel-encased composite beam. Compared with traditional composite beams, the new type of steel-encased composite beams have the advantages of improvements in the flexural capacity, the fire-resist capacity and the comprehensive economic index of the beams, and the convenience of construction process. In the project, steel - concrete composite beam in the torsion condition is many, also mostly is at the compound condition. In the domestic and foreign, the composite beam's the research is turned to be less, therefore the new steel-encased composite beam which carries on the torsion research has the important practical significance and the broad project application prospect.This article is based on the new composite beam's anti-curved performance research, to conduct the experimental study and the theoretical analysis of its torsion performance. The details are as followings..1. The 2 steel-encased concrete T section composite beam's pure torsion experiment and 3 steel-encased concrete T section composite beam's combine torsion experiment were completed. The composite beam's torque-ratio of torsion, the load-deflection curves, relational curve of section strain were obtained. We studied this new steel-encased concrete composite beam's destruction shape, worked mechanism and the crack development and the distributed situation under pure torsion and combine torsion.2. In the foundation of experimental analysis, the steel-encased concrete T composite beam dehiscence mechanism is conducted the further research under purely turned. Through the elasticity plastic theory, the composite beam dehiscence torque formula is proposed, basically tallied with the test result. This article uses the spatial truss model with variable angle, and proposes the limit torsion's strength calculation formula which may supply the design reference of pure torsion. The formula computed result and the experimental value tallies.3. In the foundation of experimental analysis, the paper defines how to differentiate the big or small torsion-bending ratio, and carries on the theoretical analysis of the composite beam's dehiscence torque and the limit torque under the combine function. Separately it produces the composite beam in big, small torsion-bending ratio as well as the combine torsion's related equation, and its form is simple, easy to operate.4. Finally, Construction design suggestions and study expectation of this new type of steel-encased concrete composite beam are advanced according to the results of test research, theoretical analysis and computer simulation.