Analysis of Stress and Deflection about Steel-Concrete Composite Girders Considering Slippage and Shrink & Creep Under Bending
Steel-concrete composite beams are composed of concrete slabs and steel girders by shear connectors. Due to the limited rigidity of shear connector and the shrink & creep property of concrete, the relative slippage exists between concrete slab and steel girder under bending, and it is difficult to analyze the effect of those factors by the ordinary beam theory , the finite element method(FEM) and so on. A differential equation of equilibrium is constituted corresponding to the compatibility of deformation and the equilibrium of forces about steel-concrete composite beams under particular assumed condition. Finite difference method (FDM) and variation principle are used to solve the differential equation. An example of steel-concrete composite T girder is given to analyze the effect of slippage and concrete shrink & creep on its stress and deflection. The concrete slab stress increases with the rigidity increment of the shear connectors. The stress of the steel girder and the deflection of the composite girder decrease with the rigidity increment of the shear connectors.
Creep Effects in Composite Beams with Flexible Shear Connectors
This paper presents a method for the viscoelastic analysis of composite steel‐concrete beams with flexible shear connectors. In particular, the proposed method evaluates the effects of the connection device's deformability on the migration of the stresses from the concrete slab to the steel beam, which occurs with time as a result of creep and shrinkage of the concrete part. The mathematical formulation of this problem involves the equations of equilibrium, compatibility, and constitutive relationships, i.e., an elastic law for the steel part and an integral‐type creep law for the concrete part. Thus, the problem is governed by a coupled system of three equations, of which two are integral‐differential‐type equations. This system of equations is resolved by numerical step‐by‐step techniques. Finally, a numerical analysis is applied to show the influence of the main parameters.
Targeting oral anticoagulation
Clinical Pharmacology & Therapeutics (2000) 68, 4–5; doi: 10.1067/mcp.2000.108197