Abstract

In order to correctly predict the kinematics of complex structures, analysis using three-dimensional finite elements (3DFEs) seems to be the best alternative. However, simulation of large multi-layered structures with many plies can be una ordable with 3DFEs because of the excessive computational cost, especially for non-linear materials. In addition, the discretization of very thin layers can lead to highly distorted FEs carrying numerical issues, therefore, reduced models arise as an a ordable solution. This paper describes a new finite element formulation to perform numerical simulations of laminated reinforced concrete structures. The intention of this work is that the proposed scheme can be applied in the analysis of real-life structures where a high amount of computational resources are needed to fulfill the meshing requirements, hence the resulting formulation has to be a compromise between simplicity and efficiency.
So that, the condensation of a dimension (thickness), mandatory to model three-dimensional structures with twodimensional finite elements (2DFEs), leads to refer all layers contained within such FEs to a plane, which is typically named middle plane or geometrical plane, since its sole function is to serve as a geometrical reference. This work is based on the assumption that the geometrical plane has to be distinguished from a mechanical plane, which is where the resultant sti ness of all layers is contained. It is also assumed in this work that the mechanical plane changes its position due to non-linear response of the component materials.

Abstract

The construction of confined masonry buildings has become a good choice to meet the housing needs of low-income families in
big cities. Despite this, current building codes for such construction allow the use of highly simplified analysis techniques that have hardly changed in the last 40 years. This paper is based on numerical simulation and discusses the need to combine and improve existing techniques in finite-element method (FEM) analysis for composite materials, to assess the overall structural behavior of reinforced concrete structures with masonry in-fills, and consequently to support the derivation of rational rules for analysis and design. Through the use of a simple yet powerful shell finite element (FE), state-of-the-art theories of mixtures to analyze composite materials, a computational tool to generate the volume fraction of composites, and the Mexican building code, this paper attempts to be a guide to numerical reproduction of the overall behavior of confined masonry structures.