Static Analysis Of Steel-encased Concrete Composite Beam

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. Concrete is poured into the new type of composite beam's U-shape section and served as the rib of the T-shape composite beam. Its flange adopts cast-in-situ concrete floor. The web and concrete flange floor are integrated by shear connectors and work together.Test research, theoretical analysis and computer simulation have been carried out in this article to study the new type of composite beam. The details are as followings.(1) Eight specimens of this type of beam have also been tested. Among them there are seven full shear connection composite beam and one partial shear connection composite beam. Failure modes of the eight specimens, construction measures of longitudinal shear connectors and loading capacity are tested. From the test, the test parameters of this new type of composite beam's loading capacity have been gotten.(2) The full shear connection composite specimens' bending strength of cross section is analyzed. The calculation procedure is performed and the moment-curvature curves are acquired. The calculated results are compared to the results based on the theory of 'simplified rectangular block' and the simplified calculation method of the new type of composite beam is required. On the basis of obtaining the relationship of moment-curvature, the specimens' load-displacement curves are illustrated by adopting finite difference method, interpolation method and numerical integral method and the calculated results are compared to the test ones.(3) Numerical simulation is conducted by nonlinear finite element method. And the distribution of concrete cracks, stress contour figures, strain contour figures, load-displacement curves and slip distribution curve are acquired. The simulated results are contrasted to the test ones and they prove the correctness of the test results and theoretical ones.(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.