Optimización topológica de una bovedilla de espuma de poliestireno con mezcla de densidades

Abstract

The traditional manufacturing processes to fabricate slabs of polystyrene foam (EPS) are limited to produce them with an uniform density within the work piece from certain length; this slabs are widely used in the construction of dwellings in Mexico. However, when the loading conditions of the slab are analyzed, it is evident that there are zones of material that have low stress values. Recently, new technologies as the continuous molding to manufacture pieces with mixed densities localized at different areas have been developed, which has led to consider perform an optimization to provide information about the optimal distribution of the materials of different densities in order to decrease the amount of raw material used without affecting the overall mechanical strength required from the piece. The topological optimization is one of the methods used in the aerospace, automotive and in the construction industry. To perform this optimization process is necessary to know accurately the mechanical properties of the material forming the piece. The behavior of the EPS slab used in the construction industry is analyzed in this work. This constructive element operates under bending loads and fails due tensile stresses at the bottom of the piece. Uniaxial tensile tests were performed to determine the mechanical properties of each density. Based on the stress-strain curves tendency an elasticmultilinear model was used to analyze the slab using the finite element method (FEM). The EPS slabs are currently made with a density of 12 kg/m3 . The topological optimization using the Optimal Criteria method (OC) is presented. Using this procedure, a 15 % saving in material was obtained, preserving the mechanical strength of the initial slab.