Weak-Form Quadrature-Element Method for Creep and Shrinkage Analysis of Steel–Concrete Composite Beams

Abstract

In this paper, a displacement-based weak-form quadrature element (WQE) is formulated and implemented for long-term response analysis of steel–concrete composite beams. The effects of creep and shrinkage taking place in reinforced concrete slabs are considered by using an integral type viscoelastic model. Timoshenko and Kant higher-order beam theories are applied to depict the reinforced concrete slab and steel beam, respectively, so as to achieve accuracy close to that of the 3D shell model, but at a much lower computational cost. The proposed model and program are verified through comparisons with the 3D shell and classical beam models. To investigate the improvement of convergence performance contributed by the differential quadrature technique, detailed comparisons are made between the WQE and conventional finite element. Numerical results show that the composite beams modeled with the Timoshenko-Kant kinematical assumption can achieve accuracy close to that of the 3D shell model; due to the ability to conveniently adjust interpolation order, the proposed WQE acquires much higher computational efficiency than the conventional finite element; the severe numerical smoothness problem common in the displacement-based finite element model (FEM) is significantly alleviated by the higher-order WQE method.