Marcello Goulart Teixeira - Academia.edu (original) (raw)

Papers by Marcello Goulart Teixeira

Research paper thumbnail of Uma algoritmo de agrupamento heterogêneo para formação de grupos de aprendizagem

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of Modelo Numérico Para Análise De Tensões Residuais Geradas Em Tratamentos Térmicos De Peças De Aço

Mecánica Computacional, 2002

O objetivo deste trabalho é fazer uma modelagem numérica por elementos finitos das tensões residu... more O objetivo deste trabalho é fazer uma modelagem numérica por elementos finitos das tensões residuais em peças de ligas ferro-níquel submetidas a tratamentos térmicos, levando em conta a influência das mudanças de fase. Com este objetivo, foram desenvolvidos códigos computacionais, orientados a objetos, para análise térmica não-linear acoplada à análise da micro-estrutura. Códigos implementados em POO também foram criados para análise elasto-plástica, onde a distribuição de temperatura e as frações parciais dos constituintes são dados de entrada. As propriedades termomecânicas do material são consideradas dependentes tanto da temperatura quanto da fração parcial de cada constituinte. No tratamento térmico é considerada a formação de martensita segundo o esquema de Koistinen & Marburger (1959) e as transformações difusionais são modeladas segundo o esquema proposto por Avrami (1939). São consideradas, durante a transformação, além das deformações térmica, elástica e plástica, a deformação devida à transformação e a deformação plástica induzida pela transformação, esta última sendo uma deformação plástica que surge mesmo para estados de tensão abaixo da tensão de escoamento. São apresentados resultados numéricos da aplicação dos códigos a tratamentos de têmpera por jato d'água e de têmpera progressiva.

Research paper thumbnail of Development of a new fuzzy exposure model

Progress in Nuclear Energy, Apr 1, 2010

ABSTRACT The aim of this work is the development of a fuzzy exposure model to estimate the radiat... more ABSTRACT The aim of this work is the development of a fuzzy exposure model to estimate the radiation exposure of a population living in an area containing considerable amounts of natural uranium. A Mamdani-type fuzzy model was created from expert's opinion, considering the following main factors: body weight, food consumption rate, lifetime and exposure duration, uranium activity concentration and food diet fraction for exposed individuals. The output fuzzy sets were expressed in form of linguistic variables, such as “low”, “medium” and “high”. The fuzzy synthetic evaluation technique was also applied since this method is considered well suited for this type of application. The daily average ingestion (DAI) was then obtained for both models and converted to average daily dose (ADD).A third approach based on Monte Carlo method was employed to calculate DAI and ADD, generating probabilistic distributions of input data, allowing a better comparison between the above techniques.In the qualitative analysis, the linguistic variable obtained was satisfactory according to the expert's opinions. In the quantitative analysis, the obtained fuzzy values showed a good agreement with that calculated by Monte Carlo method, and confirmed the results of the qualitative analysis. The global results suggest that these types of fuzzy models are highly promising for exposure evaluation to ionizing radiation.

Research paper thumbnail of Microfracturing during primary migration in shales

Tectonophysics, 2017

In several geological environments, chemical reactions are coupled to rock deformation and the as... more In several geological environments, chemical reactions are coupled to rock deformation and the associated stresses induced locally interact with the far field loading. This is the case in immature shales that undergo burial and diagenesis, where the organic matter evolves with temperature into hydrocarbons which induces local volume expansion. At large scale, this mechanism is responsible for the transport of hydrocarbons from source to reservoir rocks, a process referred to as primary migration. However, how the interactions between local fluid production, microfracturing, and transport are coupled remain to be understood. Here, we analyze this coupling phenomenon by developing a discrete element model where the generation of local overpressures occurring in kerogen patches is simulated, while the surrounding rock is subjected to external loading. It is shown that, due to local fluid overpressure; microfracturing occurs and brings the fluids to migrate through the medium. The numerical results are confirmed by laboratory experiments where the network of microfractures induced in an immature Green River shale sample heated under small differential stress was imaged in three dimensions using X-ray microtomography. Moreover, the numerical simulations identify that the state of differential stress and the initial kerogen distribution constitute two key parameters that control the formation of the three-dimensional percolating microfracture network and could thus explain primary migration in shale rocks.

Research paper thumbnail of An´ alise de erros computacionais de um modelo generalizado da equac¸˜ ao

Research paper thumbnail of Using the TODIM-FSE method as a decision-making support methodology for oil spill response

Computers & Operations Research, Feb 1, 2014

This paper introduces a multi-criteria method for solving classification problems, called TODIM-F... more This paper introduces a multi-criteria method for solving classification problems, called TODIM-FSE. This name was chosen because its structure merges characteristics from two different methods: TODIM and FSE. In order to demonstrate TODIM-FSE, a model was constructed aimed at helping potential users to decide upon suitable contingency plans for oil spill situations. The model is envisaged as embedded within SISNOLEO (a Portuguese acronym for An Information System for Oil Spill Planning) which is subsequently described in the article. The fundamentals of this method, several key references and a case study are also provided.

Research paper thumbnail of DALIGNER Performance Evaluation on Intel Xeon Phi Architecture

EPiC series in computing, Mar 18, 2019

In bioinformatics, DNA sequence assembly refers to the reconstruction of an original DNA sequence... more In bioinformatics, DNA sequence assembly refers to the reconstruction of an original DNA sequence by the alignment and merging of fragments that can be obtained from several sequencing methods. The main sequencing methods process thousands or even millions of these fragments, which can be short (hundreds of base pairs) or long (thousands of base pairs) read sequences. This is a highly computational task, which usually requires the use of parallel programs and algorithms, so that it can be performed with desirable accuracy and within suitable time limits. In this paper, we evaluate the performance of DALIGNER long read sequences aligner in a system using the Intel Xeon Phi 7210 processor. We are looking for scalable architectures that could provide a higher throughput that can be applied to future sequencing technologies.

Research paper thumbnail of Simulation of Sand Arching by Discrete Element Method

Mecánica Computacional, 2010

The main objective of this work is the simulation of the sand arching contained in a container st... more The main objective of this work is the simulation of the sand arching contained in a container stuck using an implementation of the DEM that considers circular elements of variable size limited to 2D space. It is also studied the influence of roughness of the container wall on the arching. The studies of arching sand have application in different areas of knowledge such as civil engineering (foundations, design of silos), Petroleum Engineering (production of sand) and physics of granular materials.

Research paper thumbnail of SPH e redução de modelos aplicados à dinâmica dos fluidos

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Apr 14, 2017

Research paper thumbnail of Elastoplastic Modeling Using The Successive Linear Approxitamtion Method

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Apr 14, 2017

The goal of this work is to model elastoplastic materials. More precisely, it will be considered ... more The goal of this work is to model elastoplastic materials. More precisely, it will be considered metals with von Mises criterion. For this model the successive linear approximation method and the small plastic deformation theory will be considered. The finite element method will be employed for numeric solution for each force increment.

Research paper thumbnail of Uma abordagem do algoritmo do montador de DNA SOAPdenovo

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Nov 18, 2015

Resumo. Em bioinformática, existem vários programas disponíveis para montagem de sequência de DNA... more Resumo. Em bioinformática, existem vários programas disponíveis para montagem de sequência de DNA [1]. Isso geralmenteé uma tarefa muito demorada, uma vez que essas sequências de DNA podem ser muito longas e complexas [2]. A escolha correta de um montador implica diretamente na quantidade de recursos computacionais utilizados para este processo. Neste trabalho, faremos uma abordagem do novo algoritmo utilizado no montador SOAPdenovo2.

Research paper thumbnail of Modelagem Elasto-plástica com o Método de Aproximações Lineares Incrementais

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of Redução de modelos aplicado ao escoamento de Poiseuille com diferenças finitas

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of An Approach to Parallel Algorithms for Long DNA Sequences Alignment on Manycore Architecture

Journal of Computational Biology, Aug 1, 2020

The DNA sequencing process has evolved rapidly due to the development of new technologies and equ... more The DNA sequencing process has evolved rapidly due to the development of new technologies and equipment capable of producing large amounts of sequencing data. Among these methods, PacBio stands out. The PacBio method uses single molecule real-time, generating sequence files composed by long reads. Storage and analysis of the data generated became a challenge ushering in the development of bioinformatic tools. One of these challenges is the alignment of these sequences. This article describes techniques and processes developed for long DNA sequence alignment using manycore architecture.

Research paper thumbnail of Avaliação de Desempenho Paralelo de Montadores de DNA Velvet e SOAPdenovo2

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of Combined FEM-DEM: Examples of Beam-Particle Interaction

Mecánica Computacional, 2010

One way to solve engineering problems is the simulation that can be done with real or virtual mod... more One way to solve engineering problems is the simulation that can be done with real or virtual models. A better approximation of reality is achieved through the use of real models. However this procedure is costly and in some situations it is technically impractical. The alternative is the simulation using virtual models, where several tests can be performed at a relatively low cost. One of the most used numerical methods in computer simulation of phenomena modeled by differential equations is the Finite Element Method (FEM). However, the FEM is not suitable for the simulation of systems where the effects of micro-mechanical discontinuity of the geometry should be taken into account, such as engineering problems involving fracture, fragmentation, impact and particulate media, among others. For these cases, the Discrete Element Method (DEM), first introduced by Cundall, interaction between each pair of particles considers the medium as being formed by a set of particles with interaction between each pair of them. But in some cases, it is necessary to take into account both continuous and particulate media. The main objective of this work is the simulation of beam-particle interaction using a computational tool developed in C++ object-oriented, where the beam dynamic is modelled with the FEM and the particles (circles) with the DEM. Among others, we introduce some examples of interaction between a structure and soil.

Research paper thumbnail of Seleção de tecnologias de comunicações no exército brasileiro utilizando os métodos multicritério de análise hierárquica, TODIM e software Sapiens

Production Journal, Nov 10, 2011

No Exército Brasileiro, as redes de comunicações apresentam características especiais. Um sistema... more No Exército Brasileiro, as redes de comunicações apresentam características especiais. Um sistema tático de comunicação deve ser uma única estrutura lógica que integra múltiplas tecnologias, como os Subsistemas de Rádio de Combate e de Dados. Este trabalho mostra um estudo de caso para a seleção de tecnologia que atenda aos critérios descritos pelo Exército. Para priorizar seis alternativas, são aplicados dois métodos que auxiliam a tomada de decisão: o método AHP Clássico e o TODIM. No estudo com o AHP, é mostrado cada passo da metodologia até a conclusão do resultado. Com o TODIM, é usado um software de apoio ao uso do método, o Sapiens. Foram realizadas entrevistas com especialistas da área de comunicações para o levantamento das informações necessárias. Considera-se que o principal resultado desse trabalho é a construção de um processo estruturado para essa seleção e não a obtenção dos resultados em si. Palavras-chave Análise de decisão multicritério. TODIM. AHP. Comunicações militares. Software Sapiens. Agradecimentos Os autores agradecem ao engenheiro militar David Fernandes Cruz Moura, professor do IME, a valiosa contribuição no desenvolvimento da aplicação desenvolvida neste artigo e o apoio na montagem do software Sapiens nos servidores do IME. Agredecem também ao engenheiro militar Anderson Fernandes Pereira dos Santos, professor do IME, o seu apoio no aprimoramento do software Sapiens.

Research paper thumbnail of Relative Lagrangian Formulation of Finite Thermoelasticity

Trends in Computational and Applied Mathematics, Oct 26, 2021

The motion of a body can be expressed relative to the present configuration of the body, known as... more The motion of a body can be expressed relative to the present configuration of the body, known as the relative motion description, besides the classical Lagrangian and the Eulerian descriptions. When the time increment from the present state is small enough, the nonlinear constitutive equations can be linearized relative to the present state so that the resulting system of boundary value problems becomes linear. This formulation is based on the well-known "small-on-large" idea, and can be implemented for solving problems with large deformation in successive incremental manner. In fact, the proposed method is a process of repeated applications of the well-known "small deformation superposed on finite deformation" in the literature. This article presents these ideas applied to thermoelastic materials with a brief comment on the exploitation of entropy principle in general. Some applications of such a formulation in numerical simulations are briefly reviewed and a numerical result is shown.

Research paper thumbnail of A New Material Model for Agglomerated Cork

Mathematical and computational applications, Nov 9, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Relative Lagrangian formulation in thermo-viscoelastic solid bodies

Continuum Mechanics and Thermodynamics, Jun 14, 2021

A model to a coupled thermal-viscoelastic finite deformation problem is presented. The nonlineari... more A model to a coupled thermal-viscoelastic finite deformation problem is presented. The nonlinearities are solved using the successive linear approximation method. This method uses the relative Lagrangian formulation and the idea of the superposed large deformation by small deformations. Furthermore, the constitutive equations are calculated at each state, with the reference configuration updated for each time step. After the problem is linearized, the finite element method is used. To exemplify the model a simulation of an oil well closure is presented.

Research paper thumbnail of Uma algoritmo de agrupamento heterogêneo para formação de grupos de aprendizagem

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of Modelo Numérico Para Análise De Tensões Residuais Geradas Em Tratamentos Térmicos De Peças De Aço

Mecánica Computacional, 2002

O objetivo deste trabalho é fazer uma modelagem numérica por elementos finitos das tensões residu... more O objetivo deste trabalho é fazer uma modelagem numérica por elementos finitos das tensões residuais em peças de ligas ferro-níquel submetidas a tratamentos térmicos, levando em conta a influência das mudanças de fase. Com este objetivo, foram desenvolvidos códigos computacionais, orientados a objetos, para análise térmica não-linear acoplada à análise da micro-estrutura. Códigos implementados em POO também foram criados para análise elasto-plástica, onde a distribuição de temperatura e as frações parciais dos constituintes são dados de entrada. As propriedades termomecânicas do material são consideradas dependentes tanto da temperatura quanto da fração parcial de cada constituinte. No tratamento térmico é considerada a formação de martensita segundo o esquema de Koistinen & Marburger (1959) e as transformações difusionais são modeladas segundo o esquema proposto por Avrami (1939). São consideradas, durante a transformação, além das deformações térmica, elástica e plástica, a deformação devida à transformação e a deformação plástica induzida pela transformação, esta última sendo uma deformação plástica que surge mesmo para estados de tensão abaixo da tensão de escoamento. São apresentados resultados numéricos da aplicação dos códigos a tratamentos de têmpera por jato d'água e de têmpera progressiva.

Research paper thumbnail of Development of a new fuzzy exposure model

Progress in Nuclear Energy, Apr 1, 2010

ABSTRACT The aim of this work is the development of a fuzzy exposure model to estimate the radiat... more ABSTRACT The aim of this work is the development of a fuzzy exposure model to estimate the radiation exposure of a population living in an area containing considerable amounts of natural uranium. A Mamdani-type fuzzy model was created from expert's opinion, considering the following main factors: body weight, food consumption rate, lifetime and exposure duration, uranium activity concentration and food diet fraction for exposed individuals. The output fuzzy sets were expressed in form of linguistic variables, such as “low”, “medium” and “high”. The fuzzy synthetic evaluation technique was also applied since this method is considered well suited for this type of application. The daily average ingestion (DAI) was then obtained for both models and converted to average daily dose (ADD).A third approach based on Monte Carlo method was employed to calculate DAI and ADD, generating probabilistic distributions of input data, allowing a better comparison between the above techniques.In the qualitative analysis, the linguistic variable obtained was satisfactory according to the expert's opinions. In the quantitative analysis, the obtained fuzzy values showed a good agreement with that calculated by Monte Carlo method, and confirmed the results of the qualitative analysis. The global results suggest that these types of fuzzy models are highly promising for exposure evaluation to ionizing radiation.

Research paper thumbnail of Microfracturing during primary migration in shales

Tectonophysics, 2017

In several geological environments, chemical reactions are coupled to rock deformation and the as... more In several geological environments, chemical reactions are coupled to rock deformation and the associated stresses induced locally interact with the far field loading. This is the case in immature shales that undergo burial and diagenesis, where the organic matter evolves with temperature into hydrocarbons which induces local volume expansion. At large scale, this mechanism is responsible for the transport of hydrocarbons from source to reservoir rocks, a process referred to as primary migration. However, how the interactions between local fluid production, microfracturing, and transport are coupled remain to be understood. Here, we analyze this coupling phenomenon by developing a discrete element model where the generation of local overpressures occurring in kerogen patches is simulated, while the surrounding rock is subjected to external loading. It is shown that, due to local fluid overpressure; microfracturing occurs and brings the fluids to migrate through the medium. The numerical results are confirmed by laboratory experiments where the network of microfractures induced in an immature Green River shale sample heated under small differential stress was imaged in three dimensions using X-ray microtomography. Moreover, the numerical simulations identify that the state of differential stress and the initial kerogen distribution constitute two key parameters that control the formation of the three-dimensional percolating microfracture network and could thus explain primary migration in shale rocks.

Research paper thumbnail of An´ alise de erros computacionais de um modelo generalizado da equac¸˜ ao

Research paper thumbnail of Using the TODIM-FSE method as a decision-making support methodology for oil spill response

Computers & Operations Research, Feb 1, 2014

This paper introduces a multi-criteria method for solving classification problems, called TODIM-F... more This paper introduces a multi-criteria method for solving classification problems, called TODIM-FSE. This name was chosen because its structure merges characteristics from two different methods: TODIM and FSE. In order to demonstrate TODIM-FSE, a model was constructed aimed at helping potential users to decide upon suitable contingency plans for oil spill situations. The model is envisaged as embedded within SISNOLEO (a Portuguese acronym for An Information System for Oil Spill Planning) which is subsequently described in the article. The fundamentals of this method, several key references and a case study are also provided.

Research paper thumbnail of DALIGNER Performance Evaluation on Intel Xeon Phi Architecture

EPiC series in computing, Mar 18, 2019

In bioinformatics, DNA sequence assembly refers to the reconstruction of an original DNA sequence... more In bioinformatics, DNA sequence assembly refers to the reconstruction of an original DNA sequence by the alignment and merging of fragments that can be obtained from several sequencing methods. The main sequencing methods process thousands or even millions of these fragments, which can be short (hundreds of base pairs) or long (thousands of base pairs) read sequences. This is a highly computational task, which usually requires the use of parallel programs and algorithms, so that it can be performed with desirable accuracy and within suitable time limits. In this paper, we evaluate the performance of DALIGNER long read sequences aligner in a system using the Intel Xeon Phi 7210 processor. We are looking for scalable architectures that could provide a higher throughput that can be applied to future sequencing technologies.

Research paper thumbnail of Simulation of Sand Arching by Discrete Element Method

Mecánica Computacional, 2010

The main objective of this work is the simulation of the sand arching contained in a container st... more The main objective of this work is the simulation of the sand arching contained in a container stuck using an implementation of the DEM that considers circular elements of variable size limited to 2D space. It is also studied the influence of roughness of the container wall on the arching. The studies of arching sand have application in different areas of knowledge such as civil engineering (foundations, design of silos), Petroleum Engineering (production of sand) and physics of granular materials.

Research paper thumbnail of SPH e redução de modelos aplicados à dinâmica dos fluidos

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Apr 14, 2017

Research paper thumbnail of Elastoplastic Modeling Using The Successive Linear Approxitamtion Method

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Apr 14, 2017

The goal of this work is to model elastoplastic materials. More precisely, it will be considered ... more The goal of this work is to model elastoplastic materials. More precisely, it will be considered metals with von Mises criterion. For this model the successive linear approximation method and the small plastic deformation theory will be considered. The finite element method will be employed for numeric solution for each force increment.

Research paper thumbnail of Uma abordagem do algoritmo do montador de DNA SOAPdenovo

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Nov 18, 2015

Resumo. Em bioinformática, existem vários programas disponíveis para montagem de sequência de DNA... more Resumo. Em bioinformática, existem vários programas disponíveis para montagem de sequência de DNA [1]. Isso geralmenteé uma tarefa muito demorada, uma vez que essas sequências de DNA podem ser muito longas e complexas [2]. A escolha correta de um montador implica diretamente na quantidade de recursos computacionais utilizados para este processo. Neste trabalho, faremos uma abordagem do novo algoritmo utilizado no montador SOAPdenovo2.

Research paper thumbnail of Modelagem Elasto-plástica com o Método de Aproximações Lineares Incrementais

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of Redução de modelos aplicado ao escoamento de Poiseuille com diferenças finitas

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of An Approach to Parallel Algorithms for Long DNA Sequences Alignment on Manycore Architecture

Journal of Computational Biology, Aug 1, 2020

The DNA sequencing process has evolved rapidly due to the development of new technologies and equ... more The DNA sequencing process has evolved rapidly due to the development of new technologies and equipment capable of producing large amounts of sequencing data. Among these methods, PacBio stands out. The PacBio method uses single molecule real-time, generating sequence files composed by long reads. Storage and analysis of the data generated became a challenge ushering in the development of bioinformatic tools. One of these challenges is the alignment of these sequences. This article describes techniques and processes developed for long DNA sequence alignment using manycore architecture.

Research paper thumbnail of Avaliação de Desempenho Paralelo de Montadores de DNA Velvet e SOAPdenovo2

Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Aug 25, 2015

Research paper thumbnail of Combined FEM-DEM: Examples of Beam-Particle Interaction

Mecánica Computacional, 2010

One way to solve engineering problems is the simulation that can be done with real or virtual mod... more One way to solve engineering problems is the simulation that can be done with real or virtual models. A better approximation of reality is achieved through the use of real models. However this procedure is costly and in some situations it is technically impractical. The alternative is the simulation using virtual models, where several tests can be performed at a relatively low cost. One of the most used numerical methods in computer simulation of phenomena modeled by differential equations is the Finite Element Method (FEM). However, the FEM is not suitable for the simulation of systems where the effects of micro-mechanical discontinuity of the geometry should be taken into account, such as engineering problems involving fracture, fragmentation, impact and particulate media, among others. For these cases, the Discrete Element Method (DEM), first introduced by Cundall, interaction between each pair of particles considers the medium as being formed by a set of particles with interaction between each pair of them. But in some cases, it is necessary to take into account both continuous and particulate media. The main objective of this work is the simulation of beam-particle interaction using a computational tool developed in C++ object-oriented, where the beam dynamic is modelled with the FEM and the particles (circles) with the DEM. Among others, we introduce some examples of interaction between a structure and soil.

Research paper thumbnail of Seleção de tecnologias de comunicações no exército brasileiro utilizando os métodos multicritério de análise hierárquica, TODIM e software Sapiens

Production Journal, Nov 10, 2011

No Exército Brasileiro, as redes de comunicações apresentam características especiais. Um sistema... more No Exército Brasileiro, as redes de comunicações apresentam características especiais. Um sistema tático de comunicação deve ser uma única estrutura lógica que integra múltiplas tecnologias, como os Subsistemas de Rádio de Combate e de Dados. Este trabalho mostra um estudo de caso para a seleção de tecnologia que atenda aos critérios descritos pelo Exército. Para priorizar seis alternativas, são aplicados dois métodos que auxiliam a tomada de decisão: o método AHP Clássico e o TODIM. No estudo com o AHP, é mostrado cada passo da metodologia até a conclusão do resultado. Com o TODIM, é usado um software de apoio ao uso do método, o Sapiens. Foram realizadas entrevistas com especialistas da área de comunicações para o levantamento das informações necessárias. Considera-se que o principal resultado desse trabalho é a construção de um processo estruturado para essa seleção e não a obtenção dos resultados em si. Palavras-chave Análise de decisão multicritério. TODIM. AHP. Comunicações militares. Software Sapiens. Agradecimentos Os autores agradecem ao engenheiro militar David Fernandes Cruz Moura, professor do IME, a valiosa contribuição no desenvolvimento da aplicação desenvolvida neste artigo e o apoio na montagem do software Sapiens nos servidores do IME. Agredecem também ao engenheiro militar Anderson Fernandes Pereira dos Santos, professor do IME, o seu apoio no aprimoramento do software Sapiens.

Research paper thumbnail of Relative Lagrangian Formulation of Finite Thermoelasticity

Trends in Computational and Applied Mathematics, Oct 26, 2021

The motion of a body can be expressed relative to the present configuration of the body, known as... more The motion of a body can be expressed relative to the present configuration of the body, known as the relative motion description, besides the classical Lagrangian and the Eulerian descriptions. When the time increment from the present state is small enough, the nonlinear constitutive equations can be linearized relative to the present state so that the resulting system of boundary value problems becomes linear. This formulation is based on the well-known "small-on-large" idea, and can be implemented for solving problems with large deformation in successive incremental manner. In fact, the proposed method is a process of repeated applications of the well-known "small deformation superposed on finite deformation" in the literature. This article presents these ideas applied to thermoelastic materials with a brief comment on the exploitation of entropy principle in general. Some applications of such a formulation in numerical simulations are briefly reviewed and a numerical result is shown.

Research paper thumbnail of A New Material Model for Agglomerated Cork

Mathematical and computational applications, Nov 9, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Relative Lagrangian formulation in thermo-viscoelastic solid bodies

Continuum Mechanics and Thermodynamics, Jun 14, 2021

A model to a coupled thermal-viscoelastic finite deformation problem is presented. The nonlineari... more A model to a coupled thermal-viscoelastic finite deformation problem is presented. The nonlinearities are solved using the successive linear approximation method. This method uses the relative Lagrangian formulation and the idea of the superposed large deformation by small deformations. Furthermore, the constitutive equations are calculated at each state, with the reference configuration updated for each time step. After the problem is linearized, the finite element method is used. To exemplify the model a simulation of an oil well closure is presented.