Analytical and Numerical Modeling of Prestressed Continuous Steel-Concrete Composite Beams

Abstract

A loading capacity analysis is conducted for prestressed continuous steel-concrete composite beams. On the basis of the basic theoretical framework of the solution of externally unbonded prestressed structures, formulas for calculating the three characteristic loads (crack, yield, and ultimate loads) of two-span prestressed continuous composite beams under symmetric concentrated loads are proposed and extended to general cases. The variation of tendon force is considered and the adopted limit equilibrium approach only requires the development of equilibrium equations, which avoids the solution of cumbersome simultaneous deformation compatibility equations. Furthermore, an elaborate finite element model is presented for simulating the nonlinear behavior of prestressed continuous composite beams by using the commercial finite element package. The numerical model considering both the material and geometric nonlinearities can fully reflect the complex behaviors of prestressed continuous composite beams during the whole loading process. The comparisons among the analytical, numerical, and experimental results demonstrate that the analytical method provides a convenient and reliable tool for a routine design practice and the finite element model provides an excellent numerical simulation for the nonlinear behavior of prestressed continuous composite beams.