https://ri.ufs.br/jspui/handle/riufs/2494 2026-07-07T21:32:34Z https://ri.ufs.br/jspui/handle/riufs/25349 Título: Geração de modelos de bielas e tirantes para estruturas de concreto armado por otimização topológica discreta via método ground structure Autor(es): Brito, Thalyson Issac de Jesus Abstract: The Strut-and-Tie Model (STM) is widely used for the design of reinforced concrete structures in D-regions, where the assumption of linear strain distribution is no longer valid. Traditionally, the definition of a STM relies heavily on the engineer’s experience and subjective interpretation of force flow, which may lead to conservative or inefficient solutions. In this context, this dissertation investigates the use of discrete topology optimization, based on the Ground Structure Method, as an auxiliary tool for the automated generation of strut-and-tie models. The proposed approach employs a bilinear material model that distinguishes between tensile and compressive behavior, combined with discrete and geometric filtering techniques to obtain simplified and directly interpretable topologies. Five numerical examples were analyzed: a simply supported beam used as a reference problem, a continuous beam and three structures representative of D-regions — a coupled shear wall, a deep beam with an opening, and a dapped beam. The results show that the method successfully identifies the fundamental load transfer mechanisms, producing physically consistent strut-and-tie models that are in good agreement with solutions reported in the literature. The application of separate filters for tension and compression elements revealed that the sensitivity of the optimal topology depends on the structural nature of the problem, allowing the exploration of alternative layouts without compromising structural feasibility. The study concludes that discrete topology optimization via the Ground Structure Method is a promising tool to support the design of strut-and-tie models in reinforced concrete structures. 2026-02-06T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/23599 Título: Operação de reservatórios por otimização estocástica explícita baseada nos momentos estatísticos: redução da dependência da distribuição de probabilidade Autor(es): Siqueira, José Ítalo Porto 2025-07-25T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/21803 Título: Aplicações do método de homogeinização assintótica e a técnicas de camadas fictícias em formulações variacionais zig-zag de alta ordem para vigas compósitas laminadas Autor(es): Leite, Leonardo Fellipe Prado Abstract: In the field of materials mechanics, many structural problems exhibit periodic characteristics or can be approximated as such, related to the variation of elastic modules due to the heterogeneity of the internal structure, external forces on the body and/or geometry, and which may also occur over time in a manner that is not necessarily periodic (combined effects of seasonality, temporal variation of external forces and/or, for example, fatigue or stiffening/softening due to the evolution of the internal structure). The more repetitive and complex the structure, the more challenging it becomes to solve the problem, as classical numerical techniques require modeling in two or three dimensions and very fine discretization of the domain, resulting in high computational costs. Additionally, it is observed in nature that most materials are heterogeneous at some scale, and their properties may vary randomly or in a standardized manner. Examples include concrete, whose behavior varies with its components and proportions; wood, with its anisotropic characteristics; and composite materials reinforced with fibers or particles, which are essential for ensuring the mechanical efficiency of structures. To avoid direct modeling of problems with rapidly oscillatory coefficients, mathematical homogenization methods are essential, as they aim to transform these coefficients into homogeneous equivalents. This work proposes a twodimensional modeling of heterogeneous materials beams by concurrently utilizing high-order zig-zag multilayer theories and the one-dimensional asymptotic homogenization method, allowing the description of periodic or random materials through fictitious layer techniques. Based on problems resolved using experimental results from the literature, the results demonstrate that the methodology is highly efficient, as it maintains good accuracy in twodimensional models even when using one-dimensional functions for composite, laminated and periodic materials problems. 2025-02-20T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/21583 Título: Modelo de otimização mecanicista e funcional aplicado ao dimensionamento de pavimentos semirrígidos Autor(es): Silva, Diewelly Maria Abstract: Road networks are critical for the global transportation of goods and passengers, accounting for the largest share of infrastructure investments. Since pavement design directly impacts the Life Cycle Cost (LCC) of pavement, achieving optimal solutions within specific technical and economic contexts is highly desirable. The primary objective of this research was to optimize the structural design of flexible and semi-rigid pavement layers, considering variables such as structural type, layer thicknesses, and material costs. Consequently, the application of optimization techniques has proven to be highly effective in achieving suitable pavement designs. Intelligent search algorithms emerge as valuable tools in the quest for the "ideal project," maximizing benefits while minimizing pavement construction costs. This technique was implemented by means of the free software and numerical computation platform Octave, integrating mechanistic-empirical, functional, and economic approaches to optimize pavement layer thicknesses. The ELSYM5 software served as a specialized subroutine for calculating critical stresses and strains in the pavement. These analysis results were evaluated using performance prediction models to estimate damage and service life. The mechanically suitable pavement structure was also subjected to a performance analysis of Roughness (International Roughness Index – IRI). Given that feasible solutions are those with economic viability, i.e., with LCC within the available budget, various optimization techniques were tested and compared to the engineering solution applied in a Monitored Section of BR-101/SE. Among the four optimization techniques tested in this research, evolutionary algorithms stood out as a robust and promising approach, primarily due to their ease of implementation and for providing the most economically viable technically feasible solution, with an estimated 18% LCC savings compared to the solution applied on BR-101/SE. 2024-08-29T00:00:00Z