F.E. ANALYSIS OF COMPOSITE BEAMS WITH PARTIAL INTERACTIONS USING HIGHER ORDER SHEAR DEFORMATION THEORY

Abstract

This dissertation work presents an finite element model for the analysis of steel—concrete composite beams with partial shear interaction between the adjacent layers as well as transverse shear deformation of the beam by using higher order shear deformation theory (HSDT), where there is no need of incorporating any shear correction factor- as in first order shear deformation theory (FSDT) and the model is free from shear locking problem. A third order variation of the axial displacement of the fibres over the beam depth is taken to have a parabolic variation of shear stress which is also made zero at the beam top and bottom surfaces. This model also includes the slip to occur between two adjacent layers. To interpret the effect of slip a general linear viscous—elastic spring is considered in the interaction phase. The composite action is provided by a continuous shear connection which enables relative longitudinal and vertical displacements to occur between the two components. The numerical solution is obtained by means of the finite element method considering longitudinal slip (HSDT'), vertical slip (HSDT2) separately and also combination of both longitudinal and vertical slips (HSDT3).The present result are and compared with the result from standard literature. Extensive numerical simulations are carried out on simply supported and two-span continuous composite beams to evaluate the effects of the shear deformability of the steel member on the overall structural response. The numerical results obtained with the proposed model are compared with other composite beam model with partial shear interaction which does not include the higher order shear deformation and vertical slip. Parametric studies have been performed to investigate* the influence of shear by varying material and geometric parameters, such as interlayer slip modulus (K), flexural-to-shear moduli ratios (E/G) and span-to-depth ratios (LIh). While this dissertation is mainly concerned with the behaviour of steel—concrete composite beams, the proposed formulation can be adopted for the analysis of generic composite systems which exhibit longitudinal and transverse partial interaction or to perform parametric studies to evaluate the influence of the partial interaction on the composite behaviour investigated.