جستجو در تالارهای گفتگو

EFFECTIVE STIFFNESS MODEL FOR REINFORCED CONCRETE SLABS By Maria Anna Polakl ABSTRACT: A simple procedure for calculating deflections of reinforced concrete two-way slabs is presented in this paper. The material model for reinforced concrete based on the effective stiffness approach has been implemented in a finite-element program incorporating Mindlin-plate-bending elements. Uncracked concrete is treated as an isotropic linear elastic material, and after cracking, the concrete is considered to be an orthotropic material. The reduced stiffness coefficients after cracking are calculated from the effective moments of inertia in the x- and y-directions. These effective moments of inertia are determined using the formula proposed by Branson (1963). The influence of both bending and torsional moments is included in the formulation. The proposed model has been verified by comparisons with results from tests on slabs with various loading and boundary conditions. A study has also been undertaken to check the sensitivity of the proposed formulation when applied to the analysis of slabs with different reinforcement ratios, boundary conditions, and reinforcement orientations. polak1996.pdf