Generalized Unified Calculation Method Of Steel - Concrete Composite Beams

Steel-concrete composite beam and steel reinforced concrete beam is most widely used composite beam, the stress performance and failure mode are very similar, the analysis of bending, shear strength and deformation are also the same. So, these two types of composite beams for the unified theory may be calculated. However, the current domestic and international codes are categorized them differently, the bearing capacity and the formula of deformation, which is in accordance with their respective test results, does not converge and the calculating process is complicated. Obviously, it has a theoretical and practical value in order to improve our compsite beam design technical by unifiying different theory about all kinds section compsite beam. Therefore, generalized steel-concrete composite beams refer to SCC and SRC beam in this article, and discussed unified calculation theory for generalized steel-concrete composite beams.A unified formula and design method was studied in this article in the bend, shear strength and deformation of generalized steel-concrete composite beams. The work is as follows:(1) A unified bend strength formula is derived basing on the plane cross-section assumption in SCC and SRC beam. The results of the formula in this article accord with the code formula and tests. And this formula could be easily exchanged as general steel beam and reinforced concrete beam, and with clear physical meanings.(2) By the analysis of the whole force performance process of the composite beam ,a unified model about the slip effect of generalized steel-concrete composite under load action was proposed, and a unified formula about short-term stiffness and deflection of generalized steel-concrete composite considering slip effect was established, and the slip effect in hort-term stiffness and deflection was discussed by comparing calculation results with test results.(3) A unified formula about bending strength of generalized steel-concrete composite considering slip effect was established by the unified model about the slip effect, and the slip effect in bend strength was discussed by comparing calculation results with test results. (4) Truss-arch model of steel-concrete composite beam and steel reinforced concrete beam was proposed, and a unified formula about shear strength of generalized steel-concrete composite considering slip effect was established by force analysis truss-arch model and double-axis concrete softening strength criteriono. And the slip effect in shear strength was discussed by comparing calculation results with test results.