Hygrothermal analysis of ceramic coating durability under thermal fluctuations on building facades in Brasília Gilberto Gomes, Luis Silva, Elton Bauer Journal of Infrastructure Preservation and Resilience, 2025 Building facades are continuously subjected to various external agents, such as solar radiation and temperature fluctuations, which significantly contribute to the degradation of building materials. Understanding these effects is crucial for improving the durability and performance of facades in diverse climatic conditions. This study focuses on the hygrothermal analysis of ceramic coatings applied to vertical facades in Brasília, the capital of Brazil, over a one-year period. The analysis is performed on three distinct colors of ceramic finishes – white, red, and black – and aims to evaluate the impact of thermal variations and solar radiation on the durability of these coatings. Using advanced hygrothermal modeling with the WUFI software, the study quantifies the thermal fluctuations and their effects on the ceramic materials, considering their color-dependent thermal absorption properties. The findings highlight which facades are most susceptible to thermal damage and provide valuable insights for designing maintenance strategies and improving the longevity of ceramic coatings in regions with extreme temperature changes. This research contributes to the understanding of thermal stresses in building facades and offers guidelines for enhancing the durability of ceramic finishes exposed to varying climatic conditions.
A new methodology to predict damage tolerance based on compliance via global-local analysis Gilberto Gomes, Thiago A A Oliveira, Alvaro M Delgado Neto Frattura Ed Integrita Strutturale, 2021 Over the years several design philosophies to fatigue developed in order to combine structural safety and economy to manufacturing and operating aircraft process. The safe-life approach, which consists of designing and manufacturing a safe aeronautical structure throughout its useful life, results in factors that oversize the structural elements, preventing the possibility of failure and evidently leading to high design costs. On the other hand, the approach based on the damage tolerance concept, in which it is assumed that the structure, even whether damaged, is able to withstand the actions for which it was designed until the detection of a crack due to fatigue or other defects during its operation. Here, we propose a new methodology to the damage tolerance problem in which two-dimensional global-local analysis at different levels of external requests will be made by means of compliance, aimed at finding a relationship between fatigue life and the Paris constant. Moreover, the BemCracker2D program for simulating two-dimensional crack growth is used. This methodology has been proved to be an efficient and applied alternative in the damage tolerance analysis.
Differential evolution algorithm for identification of structural damage in steel beams Brunno Emidio Sobrinho, Gilberto Gomes, Welington Vital da Silva, Ramon Silva, Erwin U. L. Palechor, et al. Frattura Ed Integrita Strutturale, 2020 Problems involving errors and uncertainties from the use of numerical and experimental responses of beams using optimization processes have been studied by many researchers. In this field, to simulate the real behavior of structures, especially in problems involving damage, it is required to have reliable experimental results in order to adjust a numerical model. These difficulties may be associated for example to modeling the connection stiffness, support conditions, or relevant parameters in structures involving damages among others. This paper proposes a new methodology to detect damage in steel beams using the Differential Evolution Technique based on experimental and numerical data. The results show a great potential of the methodology to solve damage detection problems.
An object-oriented approach to dual reciprocity boundary element method applied to 2D elastoplastic problems Gilberto Gomes, Alvaro Martins Delgado Neto, Luciano Mendes Bezerra, Ramon Silva Multidiscipline Modeling in Materials and Structures, 2019 Purpose The purpose of this paper is to describe further developments on a novel formulation of the boundary element method (BEM) for inelastic problems using the dual reciprocity method (DRM) but using object-oriented programming (OOP). As the BEM formulation generates a domain integral due to the inelastic stresses, the DRM is employed in a modified form using polyharmonic spline approximating functions with polynomial augmentation. These approximating functions produced accurate results in BEM applications for a range of problems tested, and have been shown to converge linearly as the order of the function increases. Design/methodology/approach A programming class named DRMOOP, written in C++ language and based on OOP, was developed in this research. With such programming, general matrix equations can be easily established and applied to different inelastic problems. A vector that accounts for the influence of the inelastic strains on the displacements and boundary forces is obtained. Findings The C++ DRMOOP class has been implemented and tested with the BEM formulation applied to classical elastoplastic problem and the results are reported at the end of the paper. Originality/value An object-oriented technology and the C++ DRMOOP class applied to elastoplastic problems.
Numerical simulation of fatigue crack propagation in mixed-mode (I+II) using the program BemCracker2D Pedro G.P. Leite, Gilberto Gomes International Journal of Structural Integrity, 2019 Purpose The purpose of this paper is to present the application of the boundary element method (BEM) in linear elastic fracture mechanics for analysis of fatigue crack propagation problems in mixed-mode (I+II) using a robust academic software named BemCracker2D and its graphical interface BemLab2D. Design/methodology/approach The methodology consists in calculating elastic stress by conventional BEM and to carry out an incremental analysis of the crack extension employing the dual BEM (DBEM). For each increment of the analysis, the stress intensity factors (SIFs) are computed by the J-Integral technique, the crack growth direction is evaluated by the maximum circumferential stress criterion and the crack growth rate is computed by a modified Paris equation, which takes into account an equivalent SIF to obtain the fracture Modes I and II. The numerical results are compared with the experimental and/or BEM values extracted from the open literature, aiming to demonstrate the accuracy and efficiency of the adopted methodology, as well as to validate the robustness of the programs. Findings The paper addresses the numerical simulation of fatigue crack growth. The main contribution of the paper is the introduction of a software for simulating two-dimensional fatigue crack growth problems in mixed-mode (I+II) via the DBEM. The software BemCracker2D coupled to the BemLab2D graphical user interface (GUI), for pre/post-processing, are very complete, efficient and versatile and its does make relevant contributions in the field of fracture mechanics. Originality/value The main contribution of the manuscript is the development of a GUI for pre/post-processing of 2D fracture mechanics problems, as well as the object oriented programming implementation. Finally, the main merit is of educational nature.
