Hybrid-Mixed Stress Finite Element Models for the Physically Non-Linear Analysis of Concrete Three-Dimensional Structures

摘要

This paper presents a hybrid-mixed stress model applied to the physically nonlinear analysis of three-dimensional concrete structures. The nonlinear behaviour of concrete is modelled using Continuum Damage Mechanics. Two isotropic and elastic scalar damage models have been adopted associated with a regularization technique known as nonlocal integral model. In the implementation of the model, the effective stress and the displacement fields in the domain and the displacements on the static boundary, which includes the boundaries between elements, are independently approximated. Orthonormal Legendre polynomials are used as approximation functions. The accuracy of the model and its efficiency are assessed by analyzing three-dimensional problems for which known experimental and numerical results exist in the literature.