Nonlinear Analysis And The Experimentation Study For The New Type Of T-section Steel-encased Concrete Composite Beams

This paper is about Steel—encased Concrete T- Composite Beams which is Overcome some Shortcomings of ordinary I-beam - concrete composite beam. The composite beam with a reasonable structure of the construction process optimization, improved fire performance, and improve the overall economic indicators advantages. For this research project, reported the new Steel - encased concrete T- composite beam of the bending properties have also conducted a number of pilot studies, but its performance by torsion have not research, this is not conducive to real understanding of the composite beam performance. In order to study its torsional properties. This paper research on torsion of new Steel - encased concrete T- composite beam by experiment and FEM on five specimen. Research on the beam torsional strength have different concrete wing plates hoop rate the rate of combination of bending and torsion, deformation and failure modes effects.(1) The test show that different concrete wing plates hoop rate have little effects on torsion and deformation,but the rate of combination of bending and torsion have great effects on torsion and deformation. With the increase of the rate of bending and torsion, the ultimate destruction of composite beams from the torsional mode of destruction for the change gradually bend-destruction. In composite beams twisted-type failure, the distribution of similar destruction of concrete cracks of wing plate the same to ordinary concrete beam distribution; The torsion of combination beam increases with the increase of the rate of bending and torsion; Beam performance of the whole beam for the torsional deformation. In composite beams bend-type failure, concrete cracks in the wing panel significantly reduce. The torsion of beam decrease with the increase of the rate of bending and torsion. Composite beam deformation performance for the bending deformation.(2) The finite element method that on the basis of test show that the limits of the rate of composite beam bending and torsion is 2. When the ratio of bending and torsion less than 2, the composite beam shear-twisting bends under torsional rigidity have small difference. The pre-twisting torsional stiffness and the torsional stiffness of pure small difference,while the ratio of bending and torsion is 2. When the ratio of bending and torsion is 4, cracking before the torsional rigidity and torsional pure have little difference, cracking the torsional rigidity is obviously greater than pure torsion and bending and torsion than less than or equal to 2.(3) The formula torsional stiffness and torsional bending shear strength equation of composite beams under bending twisting torsional shear is established.We hope that our results could be useful for engineering design of the new steel -encased concrete T- composite beam.