Análise numérica da variação geométrica em blocos de concreto
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Data
2022-02-10
Autores
Silva Junior, Valdeir Alves da
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Universidade Estadual Paulista (Unesp)
Resumo
Esta pesquisa buscou determinar, através de análises numéricas, a influência no comportamento mecânico de blocos de concreto autoadensável, com finalidade de utilização na alvenaria estrutural, considerando variações nas geometrias dos blocos estudados. A pesquisa é composta por duas etapas, na primeira etapa as soluções numéricas foram feitas com o comportamento físico e mecânico dos materiais dentro do regime linear elástico, fase elástica. Na segunda etapa as soluções numéricas foram feitas com o comportamento físico e mecânico dos materiais considerando o comportamento plástico dos mesmos, fase plástica. As validações dos resultados foram feitas, para as duas etapas da pesquisa, obtendo convergências satisfatórias das curvas de tensão vs deformação, obtidas numericamente, e as comparando com os resultados experimentais. Os resultados experimentais foram adquiridos através de um trabalho experimental. As análises experimentais consistiram em ensaios de compressão utilizando prismas de dois blocos, de concreto autoadensável, com seis diferentes tipos de geometria e três formatos geométricos vazados: circulares, hexagonais e retangulares, de diferentes áreas líquidas. Nas análises numéricas foram simulados os ensaios de compressão, conforme ensaios experimentais, e buscando uma extrapolação, foram feitas simulações do critério de início de fissuração FS, o qual verifica uma maior ou menor probabilidade do início de fissuração nos prismas, e por último realizou-se análises lineares da relação entre os parâmetros relativo às diferentes geometrias dos blocos com as tensões desenvolvidas nos mesmos. Na segunda etapa da pesquisa as análises feitas foram, as relações de tensão deformação, e simulações dos FS, com o objetivo de encontrar, dentre as geometrias estudadas, qual apresentasse um melhor comportamento, frente as solicitações impostas aos prismas. Nesta pesquisa todas as análises foram realizadas através do método de elementos finitos, utilizando o software Ansys Workbench em sua versão 2020 R2 com licença acadêmica considerando as características físicas, geométricas e condições de contorno a partir das análises experimentais. As soluções numéricas, para as curvas de tensão vs deformação, tanto na primeira etapa quanto na segunda se mostraram com uma boa convergência quando comparadas com os resultados experimentais. Notou-se que as distribuições de tensões de tração e compressão nos blocos variam de geometria para geometria, podendo se desenvolver de formas diferentes na face externa e interna dos blocos com dimensões e geometrias diferentes. Para os resultados dos FS, as simulações considerando a plasticidade dos materiais, se apresentaram com soluções equivalentes às análises experimentais. As soluções dos FS mostraram que a área liquida do bloco não é o fator principal para maior ou menor resistência do bloco. As correlações lineares entre parâmetros mostraram que a disposição, dimensão e formato geométrico do vazado no bloco influência de formas diferentes no desenvolvimento de tensões no bloco.
This research aimed to determine through numerical analysis the influence on the mechanical behavior of self-compacting concrete blocks, used in structural masonry, considering variations in the geometry of the studied blocks. The research is composed of two stages, in the first one the numerical solutions were made with the physical and mechanical behavior of the materials within the linear elastic regime, elastic phase. In the second stage, numerical solutions were made with the physical and mechanical behavior of the materials considering their plastic behavior, plastic phase. The validations of the results were carried out for both stages of the research obtaining satisfactory convergences of the stress vs strain curves, obtained numerically, and comparing them with the experimental results. Experimental results were acquired through experimental work. The experimental analyzes consisted of compression tests using two-block prisms made of self compacting concrete with six different types of geometry and three hollow geometric shapes: circular, hexagonal and rectangular, with different liquid areas. In the numerical analysis the compression tests were simulated according to experimental tests, and seeking an extrapolation, simulations of the cracking initiation criterion FS were performed, which verifies a greater or lesser probability of the beginning of cracking in prisms, and finally was performed linear analysis of the relation between the parameters related to the different block geometries with the stresses developed in them. In the second stage of the research, the analyzes performed were stress-strain relations and FS simulations, with the aim of finding, among the studied geometries, which one presented a better behavior for geometrical variation in face of the demands imposed on the prisms. In this research all analyzes were performed using the finite element method, using the Ansys Workbench software in its 2020 R2 version with academic license considering the physical, geometric and boundary conditions from the experimental analyses. The numerical solutions for the stress vs strain curves, both the first and second stages of the analyzes showed good convergence when compared to the experimental results. It was noted that the tensile and compression stress distributions in blocks vary from geometry to geometry, and may develop in different ways on the external and internal face of blocks with different dimensions and geometries. For the SF results, the simulations considering the plasticity of the materials presented themselves with solutions equivalent to the experimental analyzes. The FS solutions showed that the net area of the block is not the main factor for greater or lesser block resistance. The linear correlations between parameters showed that the arrangement, dimension and geometric shape of the hollow in the block influence, in different ways, the stress development in the block.
This research aimed to determine through numerical analysis the influence on the mechanical behavior of self-compacting concrete blocks, used in structural masonry, considering variations in the geometry of the studied blocks. The research is composed of two stages, in the first one the numerical solutions were made with the physical and mechanical behavior of the materials within the linear elastic regime, elastic phase. In the second stage, numerical solutions were made with the physical and mechanical behavior of the materials considering their plastic behavior, plastic phase. The validations of the results were carried out for both stages of the research obtaining satisfactory convergences of the stress vs strain curves, obtained numerically, and comparing them with the experimental results. Experimental results were acquired through experimental work. The experimental analyzes consisted of compression tests using two-block prisms made of self compacting concrete with six different types of geometry and three hollow geometric shapes: circular, hexagonal and rectangular, with different liquid areas. In the numerical analysis the compression tests were simulated according to experimental tests, and seeking an extrapolation, simulations of the cracking initiation criterion FS were performed, which verifies a greater or lesser probability of the beginning of cracking in prisms, and finally was performed linear analysis of the relation between the parameters related to the different block geometries with the stresses developed in them. In the second stage of the research, the analyzes performed were stress-strain relations and FS simulations, with the aim of finding, among the studied geometries, which one presented a better behavior for geometrical variation in face of the demands imposed on the prisms. In this research all analyzes were performed using the finite element method, using the Ansys Workbench software in its 2020 R2 version with academic license considering the physical, geometric and boundary conditions from the experimental analyses. The numerical solutions for the stress vs strain curves, both the first and second stages of the analyzes showed good convergence when compared to the experimental results. It was noted that the tensile and compression stress distributions in blocks vary from geometry to geometry, and may develop in different ways on the external and internal face of blocks with different dimensions and geometries. For the SF results, the simulations considering the plasticity of the materials presented themselves with solutions equivalent to the experimental analyzes. The FS solutions showed that the net area of the block is not the main factor for greater or lesser block resistance. The linear correlations between parameters showed that the arrangement, dimension and geometric shape of the hollow in the block influence, in different ways, the stress development in the block.
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Prismas, Blocos vasados de concreto, Geometria, Análise numérica, Prisms, Concrete hollow blocks, Geometry, Numerical analysis