Time-Dependent Analysis of Steel-Concrete Composite Beams

Correct analysis of creep and shrinkage effects on stress and deflection is very important for normal use and safety of steel-concrete composite beams. Based on the age-adjusted effective modulus method, this paper presents a simplified finite element model to analyze the creep and shrinkage of steel-concrete composite beams with partial interaction. Effects of the slip of shear connectors on stiffness and strength can be considered in the model. The shear connector element stiffness matrix considering slip is derived in this paper. Newton-Raphson solution procedure is used to calculate the nonlinear effects of slip between concrete slab and cracking of the concrete slab on stiffness and strength of composite beam. The deflection, stress and slip of a continuous composite beam under short-term and long-term load are computed using the proposed finite element model. The numerical results are compared with the experimental results and existing values based on other numerical method, and found to be in good agreement. This proves that the model is appropriate convenient in analysis of steel-concrete composite beams.