Estudo de modelos numéricos para a análise estrutural de lajes nervuradas

Abstract

Waffle slabs are an excellent solution for the construction of building, although most of the structural analyzes for this system are simplified and can provide results that do not represent the true behavior of the structure, because part of these simplifications disregard factors that influence the final displacement of the structure. Although progress on the topic of structural analysis of waffle slabs that use realistic methods, such as the finite element method, there are many factors that need to be elucidated. Therefore, this paper aimed to analyze the best ways of modeling the waffle slabs, evaluating the influence of considering the massive region adjacent to the edge beam and the influence of the structure geometry on the final displacement of the waffle slabs. First, trough finite element, some models were created to represent the waffle slabs to validate parameters of numerical analyzes through reproduction analytical, numerical and experimental studies. Then, three finite element models are proposed, where the first modeling consists of considering the ribs modeled up to the average surface of the edge beams, the second modeling considers the formation of a massive region adjacent to the edge beam modeled only by the slab, and finally, a modeling that considers the massive region adjacent to the edge beam modeled separately, in addition to modeling through grid analogy, with the aim of analyze twenty-three slabs that had the width, height and spacing between axes ribs diversified to analysis the influence of each variable and the difference in results between the forms of modeling. The first result obtained determined the importance of eccentricity between axes of the ribs and concrete slab to obtain more realistic results; second, increasing the height and width of the ribs reduces the displacement of slab; third, the finite element modeling is a great solution for the analysis, has seen that factor like massive region adjacent to the edge beam influence in obtaining a realistic modeling. It is also noted that grid analogy offers practicality and ease of analysis. Finally, it is understood that this paper has a great contribution in the instance of the different ways of numerical modeling for structural analysis of waffle slabs, in addition to considering the parametric analysis to evaluate displacement of structure, the consumption of materials and the expense for different heights and width of the ribs, and variation in rib spacing.