Valdir Pignatta Silva

Professor

Doutorado, Escola Politécnica, USP, Brasil, 1997.

Mestrado em Engenharia de Estruturas, Escola Politécnica, USP, Brasil, 1992.


Engenheiro Civil - Escola Politécnica da USP, Brasil,1975.

About


About
Áreas de interesse:
Estruturas de concreto em situação de incêndio
Estruturas de aço em situação de incêndio
Segurança contra incêndio

Este site é dedicado a divulgar minha produção científica, bem como a área de Engenharia de Segurança contra Incêndio.

Fields of interest:
Concrete structures in fire
Steel structures in fire
Fire Safety

This site is dedicated to disseminate my scientific production as well as the area of Fire Safety Engineering

Disciplinas ministradas

- Disciplinas ministradas na graduação em engenharia civil:
Projeto de Estruturas em Situação de Incêndio
Estruturas metálicas e madeira
Projeto de estruturas
Introdução à Mecânica dos Sólidos
Mecânica Aplicada à Engenharia Civil
Estágio Supervisionado em Engenharia de Estruturas I e II

- Disciplinas ministradas na graduação em arquitetura:
Estruturas de Aço para Edifícios. Aspectos Tecnológicos e de Concepção (arquitetura)
Sistemas estruturais II (arquitetura)
Estruturas na Arquitetura III: Sistemas Reticulados e Laminares
Estruturas metálicas (arquitetura)

- Disciplinas ministradas na pós-graduação em engenharia de estruturas
Dimensionamento de Estruturas em Situação de Incêndio
Aspectos Tecnológicos dos Materiais Estruturais
Projeto de Estruturas Metálicas

- Disciplinas ministradas em curso de especialização em engenharia de estruturas:
Dimensionamento de Estruturas em Situação de Incêndio
Dimensionamento de Estruturas de Aço de Edifícios
Projeto de Estruturas de Aço de Edifícios
Materiais estruturais


Subjects

- Subjects for undergraduate in civil engineering:
Structures Fire Design
Metal structures and wood
Design of structures
Introduction to Solid Mechanics
Mechanics Applied to Civil Engineering
Supervised Internship in Structural Engineering I and II

- Subjects for undergraduate in architecture:
Steel Structures for Buildings. Technological and Conceptual Aspects
Structural systems II
Structures in Architecture III: Reticulated and Laminar Systems
Metal structures

- Subjects for post-graduate in structural engineering
Structures Fire Design
Technological Aspects of Structural Materials
Metal Structures Design

- Subjects for specialization course in structural engineering:
Structures Fire Design
Steel Structures Design for Buildings
Steel Structures Project for Building
Structural materials

Currículo


Currículo Lattes:
http://lattes.cnpq.br/2431468701531047

Google Scholar:
https://scholar.google.com.br/citations?user=qxx0sVcAAAAJ&hl=pt-BR&oi=sra

ORCID:
http://orcid.org/0000-0003-3302-8520

Research id
http://www.researcherid.com/rid/C-2047-2012

Academia.edu
https://valdirpignattasilva.academia.edu/

Researchgate:
https://www.researchgate.net/profile/Valdir_Silva/info



Mini-currículo

Professor Doutor da Poli-USP. Concluiu o doutorado em Engenharia Civil - Estruturas na Escola Politécnica da Universidade de São Paulo em 1997. Pós-doutorado pela Universidade de Coimbra. Pesquisador com bolsa de produtividade CNPq. Revisor de 21 revistas científicas: Journal of Structural Engineering (ASCE), Construction and Building Materials (Elsevier), Nonlinear Dynamics (Springer), Fire Safety Journal (Elsevier), Fire and Materials (Wiley), Journal of Structural Fire Engineering (Multi-Science),Journal of Building Engineering (Elsevier),Steel and Composite Structures an International Jounal (TechnoPress), Engineering and Computational Mechanics (ICE), Materials Research (ABM-UFSC), Journal of the Brazilian Society of Mechanical Sciences (ABCM), Latin American Journal of Solids and Structures (ABCM), REM - Revista da Escola de Minas, Materials Research (ABM/UFSC), Revista IBRACON de Estruturas e Materiais - RIEM, Revista Sul-Americana de Engenharia Estrutural - RSAEE, Revista Produção (ABEPRO), Cadernos de Engenharia de Estruturas (EESC), Revista da Estrutura de Aço (CBCA), Revista Ambiente Construído (ANTAC), Revista Facultad de Ingeniería de la Universidad de Antioquia e Revista Flammae. Assessor ad hoc da CAPES, CNPq, FAPESP, FAPEMIG e FAPERN. Foi Vice-presidente e é Diretor da ALBRASCI - Associação Luso-Brasileira para a Segurança contra Incêndio. Foi membro do Conselho Consultivo da Frente Parlamentar Mista de Segurança Contra Incêndio. Publicou mais de 60 artigos em periódicos especializados e mais de150 trabalhos em anais de eventos. Possui 8 livros publicados e 7 capítulos de livros. Possui 6 softwares e outros 200 itens de produção técnica. Participou de mais de 30 eventos no exterior e 70 no Brasil. Orientou 6 doutorados, 17 mestrados, 3 pós-doc, 2 dr.sand. e 5 IC, Atualmente orienta 4 doutorados, 3 mestrados e 2 pós-doc. Foi coordenador de projetos de pesquisa FAPESP, sendo um em andamento. Foi coordenador de convênio CAPES-Cuba. Foi pesquisador principal de projeto temático FAPESP. Coordenou 1 projeto CNPq. Foi coordenador do Programa de Pós-Graduação em Engenharia Civil da EPUSP. Atua na área de Engenharia de Estruturas, com ênfase em "Engenharia de estruturas em situação de incêndio". Interagiu com cerca de 80 colaboradores em coautorias de trabalhos científicos. Membro da IAFSS, ALBRASCI, IBRACON, ABECE e GSI/USP.

Graduated in Civil Engineering (1975), MSc/Structural Engineering (1992) and PhD/Structural Engineering (1997) at Polytechnic School of the University of Sao Paulo. Postdoctoral degree at University of Coimbra. Professor at Polytechnic School of the University of São Paulo. Dean of the Post-Graduate Program in Civil Engineering at USP with 80 researchers and 400 students (2000-2002). Main research nowadays is about Structures Fire Behavior and Design Reviewer of 21 scientific journals: Journal of Structural Engineering (ASCE), Construction and Building Materials (Elsevier), Nonlinear Dynamics (Springer), Fire Safety Journal (Elsevier), Fire and Materials (Wiley), Journal of Structural Fire Engineering (Multi-Science), Journal of Building Engineering (Elsevier),Steel and Composite Structures an International Journal (TechnoPress), Engineering and Computational Mechanics (ICE), Materials Research (ABMUFSC), Journal of the Brazilian Society of Mechanical Sciences (ABCM), Latin American Journal of Solids and Structures (ABCM), REM - Revista da Escola de Minas, Materials Research (ABM/UFSC), Revista IBRACON de Estruturas e Materiais - RIEM, Revista Sul-Americana de Engenharia Estrutural - RSAEE, Revista Produção (ABEPRO), Cadernos de Engenharia de Estruturas (EESC), Revista da Estrutura de Aço (CBCA), Revista Ambiente Construído (ANTAC), Revista Facultad de Ingeniería de la Universidad de Antioquia and Revista Flammae. Published more than 60 papers in scientific journals and more than 150 papers in congress proceedings; 8 books and 7 chapters of books. Participated in more than 30 events abroad and 70 events in Brazil. Ex-Vice-President and now Director of ALBRASCI - Luso-Brazilian Association for Fire Safety. Member of the Advisory Council of the Joint Parliamentary Fire Safety Front. CNPq researcher and ad hoc advisor to CAPES, CNPq, FAPESP, FAPEMIG and FAPERN. Coordinator of several research projects with development agencies (FAPESP, CNPq, CAPES). Principal researcher for the FAPESP thematic project.






Contact


  • Av. Prof. Luciano Gualberto, trav.3, n.380 Edifício da Engenharia Civil - Cidade Universitária - São Paulo. Brasil.
  • CEP 05508-010

Livros


SILVA, Valdir Pignatta. Estruturas de aço em situação de incêndio. 1/r. ed. São Paulo: Zigurate, 2004. v. 1. 256p .

Steel Structures in Fire

SILVA, Edson Lubas da ; SILVA, Valdir Pignatta . Dimensionamento de perfis formados a frio conforme NBR 14762 e NBR 6355. 1a.. ed. Rio de Janeiro: Centro Brasileiro da Construção em Aço, 2008. v. 1. 119p .

Papers (estruturas em incêndio)


ROMAGNOLI, Lucas Coscia ; SILVA, V.P. . About the use of semi-continuity to remove fireproof coatings in simply supported composite steel and concrete beams.. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 11, p. 296-306, 2018.

download: 1018-7118-3-PB (1).pdf .The behavior under fire conditions of composite steel and concrete beams, not subjected to local buckling (compact steel profile), was studied considering the support rotational stiffness provided by the upper longitudinal slab reinforcement, usually present by means of anti-cracking meshes, and restriction of the steel profile’s lower flange, additional procedure required for development of the support bending moment resistance. Usually composite beams at room temperature are designed as simply supported and the semi-rigidity provided by this longitudinal reinforcement, if considered under fire conditions, may lead to a lower cost solution for fire protection of composite beams. The purpose of this study is to verify the viability of this proposal, using simplified design code methods.

1018-7118-3-PB (1).pdf


Leia Mais

NASCIMENTO, Julia Souza ; AZEVEDO, Macksuel Soares ; SILVA, V.P. ; FERREIRA, Walnório Graça . Análise numérica de vigas de aço em incêndio com dilatação térmica restringida. REVISTA DA ESTRUTURA DE AÇO, v. 7, p. 56-68, 2018.

Vigas de aço tendem a expandir longitudinalmente quando submetidas a temperaturas elevadas. Em situaçõesreais, esse deslocamento axial é impedido por estruturas adjacentes que ainda podem aplicar restrição à rotação de acordo com o tipo de ligação existente. Essa interação entre os elementos favorece o surgimento de esforços internos que influenciam o comportamento da viga, a qual já apresenta capacidade resistente reduzida em resposta à degradação térmica de suas propriedades físicas e mecânicas. O objetivo desta pesquisa é simular numericamente o comportamento de vigas de aço com restrições axial e rotacional nos apoios em situação de incêndio. A análise numérica foi realizada no código computacional ANSYS v17.0, considerando‐se as não linearidades geométricas e do material.

http://www.cbca-acobrasil.org.br/lib/php/download-revista-cientifica.php?arq=101662_rea_4_julia_s_nascimento_et_al.pdf


Leia Mais

SUAZNABAR, J. S. ; SILVA, V. P. Combined axial and flexural loads in short reinforced concrete columns in fire: ultimate limit state curves using 500 °C isotherm method. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 11, p. 163-182, 2018.

download: 832-6585-3-PB.pdf .Ultimate limit state curves of short reinforced concrete columns in fire situation are going to be presented in this paper. The authors created a code developed in Matlab. It makes a discretization of the cross sections of the columns and calculates the equilibrium integrals of them. The curves were plotted with the code considering the 500 °C isotherm method.

832-6585-3-PB.pdf

Leia Mais

SILVA, Valdir Pignatta; MELÃO, ARTHUR RIBEIRO . Temperatura crítica de perfis I de aço em situação de incêndio. AMBIENTE CONSTRUÍDO (ONLINE), v. 18, p. 325-342, 2018.

O aço e demais materiais estruturais têm sua capacidade resistente reduzida com o aumento de temperatura em situação de incêndio. No caso dos perfis de aço sob campo uniforme de temperaturas, define-se temperatura crítica àquela que os conduz ao colapso. Neste artigo, considera-se que o colapso ocorre quando os valores de cálculo dos esforços solicitantes se igualarem os esforços resistentes, ambos em situação de incêndio. Para este trabalho foi desenvolvida uma ferramenta gráfica, que permite determinar de forma expedita a temperatura crítica de pilares e vigas com base no método simplificado da norma brasileira e empregando o programa AcoInc desenvolvido pelos autores. Ferramenta similar não foi encontrada na literatura pesquisada. Seu uso simplifica sobremaneira o método de dimensionamento normatizado.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-86212018000200325&lng=en&nrm=iso&tlng=pt

Leia Mais

LAREDO, Raphael C. ; SILVA, V. P. ; ALMEIDA NETO, E. S. . THE EFFECT OF THE STEEL ROOF COLLAPSE ON INDUSTRIAL BUILDINGS PORTAL FRAMES IN FIRE. REVISTA DA ESTRUTURA DE AÇO, v. 6, p. 46, 2017.

download: 2017REA.pdf .Os sistemas de cobertura empregando perfis de aço são amplamente aplicados em edificações industriais. Em algumas dessas edificações, os fechamentos laterais, incluindo os pilares que os sustentam, têm a função de impedir a propagação de um incêndio para a vizinhança. Em muitas situações, as IT´s de Corpos de Bombeiros e a ABNT NBR 14432:2001 dispensam a verificação das estruturas das coberturas, desde que seu colapso não prejudique a estabilidade dos pilares e dos fechamentos. Em incêndio, a cobertura de aço deforma-se pelo aquecimento, provocando forças horizontais nas extremidades superiores dos pilares. Assim, mesmo coberturas simplesmente apoiadas poderão levar o fechamento ao colapso. O objetivo deste trabalho será detalhar um método com base em literatura estrangeira, em que se consideram tais esforços horizontais, fornecer algumas informações não constantes do original, adaptá-lo às normas brasileiras e aplicá-lo a um estudo de caso.

2017REA.pdf



Leia Mais

CHEREM, Marcello ; SILVA, V.P. . Determination of the ULS, for columns with small dimensions, under biaxial bending and symmetrical fire conditions. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 10, p. 451-476, 2017.

download: 836-5677-3-PB.pdf .Obtaining internal load capacity, in reinforced concrete sections, at ambient temperature, under biaxial bending, is one of the most common tasks done by structural engineers, but not so common when the member is in fire situation. The intention of this paper is to show that is possible to correlate the ultimate limit state (ULS), in fire situation, with ULS at ambient temperature, for square cross sections under fire from all faces. To reach the purpose and give support to the numerical analysis of this article, a computer program, in Delphi language, called COL FIRE, is being developed by the authors.

836-5677-3-PB.pdf

Leia Mais

PIERIN, I. ; SILVA, V.P. ; VARGAS, Mauri Resende . The effect of the failure of the steel roof on the facade concrete columns of a warehouse in fire. A study case. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 10, p. 687-705, 2017.

download: 866-5795-3-PBenglish.pdf .In many situations, the Brazilian Legislation does not require verification of roof structures in a fire, since its failure will not endanger the stability of the structure. In fire, the steel roof of an industrial building deforms by heating in geometry similar to a catenary, resulting in horizontal forces in the upper extremities of the columns. Thus, even roofs that do not constitute a frame with the columns may lead them to collapse, therefore, should be protected against fire. Due to the small dimensions of the structural elements of the roof, fire coating is uneconomical. So there is a problem in the design practice. This paper presents a procedure based on British literature, which considers the horizontal load on the columns. This horizontal load must be supported by the columns and the foundations. The aim of this paper is to detail this procedure, adapt it to Brazilian standards and apply it to a case study.

866-5795-3-PBenglish.pdf

Leia Mais

SILVA, V.P.; COSTA, Carla Neves ; MELÃO, Arthur . Procedure for decreasing the required time for fire resistance of the multistory buildings. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 10, p. 1141-1162, 2017.

download: 887-6167-4-PB.pdf .The Brazilian standard ABNT NBR 15200: 2012 details a procedure for decreasing the required time of fire resistance in buildings with good fire safety characteristics. It called equivalent time method. This name can confuse the less habituated to the fire safety area, because the Brazilian procedure is not equal to the original equivalent time method, European. The purpose of this paper is to discuss the equivalent time method, to detail the origins of the Brazilian method and present their limitations no explicit in the Brazilian standard. Some unknown aspects of most researchers or technical means are presented. It should be highlighted the abundant bibliography presented to aid the understanding of a seemingly simple issue, but it incorporates many concepts of fire safety, not always understood by the users.

887-6167-4-PB.pdf

Leia Mais

SILVA, V. P.; COSTA, C. N. ; MELÃO, ARTHUR . Procedimento para redução do tempo requerido de resistência ao fogo de edifícios de múltiplos andares. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, V. 10, P. 1141-1162, 2017.

download: 887-6168-5-PB.pdf .A ABNT NBR 15200:2012 detalha um procedimento para a redução do tempo requerido de resistência ao fogo de edificações com boas características de segurança contra incêndio. Ele recebe o nome de método do tempo equivalente. Esse nome pode confundir os menos afeitos à área de segurança contra incêndio, pois o procedimento brasileiro não é equivalente ao MTE original, europeu. O objetivo deste artigo é discorrer sobre o MTE, detalhar as origens do método brasileiro e apresentar suas limitações não explícitas na norma brasileira. Apresentam-se alguns aspectos desconhecidos da maioria dos pesquisadores ou do meio técnico. Destaca-se a revisão bibliográfica apresentada ao longo do texto, para auxiliar a compreensão de um tema aparentemente simples, porém que incorpora diversos conceitos sobre segurança contra incêndio, nem sempre compreendidos pelos usuários.

887-6168-5-PB.pdf

Leia Mais

CORDEIRO, Leila Cristina Santos ; SILVA, V. P. . On the composite steel and concrete slab fire design. REVISTA DA ESTRUTURA DE AÇO, v. 5, p. 39-58, 2016.

download: 101456_mista (2) (1).pdf .Neste trabalho apresentam-se três maneiras de se dimensionar uma laje mista de aço e concreto. Para isso, optou-se por aplicar os métodos disponíveis a um caso real. Pelo mezanino da Estação de metrô Butantã, São Paulo, circulam mais de 20 000 pessoas por dia. Segundo a IT8 do CBPMESP, esse mezanino é isento de verificação das estruturas em incêndio. Mesmo assim, a Companhia do Metropolitano de São Paulo especificou um tempo requerido de resistência ao fogo de 90 min para a estrutura do mezanino que é composto de vigas de aço e laje mista. Todas as vigas foram revestidas para resistir 90 min de incêndio-padrão conforme resultados de ensaios em função do TRRF e do fator de massividade. Neste trabalho será verificada a resistência ao fogo da laje mista, conforme ABNT NBR 14323:2013, pelo método simplificado de Bailey (2000, 2000a) que inclui o efeito de membrana e por modelagem empregando o programa de computador Vulcan. O objetivo deste trabalho é comparar os resultados e verificar se há necessidade de alguma intervenção na construção, ou se poderiam ser elaborados projetos mais econômicos.

101456_mista (2) (1).pdf


Leia Mais

PARDO, Yisel Larrua ; LARRUA, Rafael ; SILVA, V. P. . Influencia del uso de métodos simplificados de temperatura en la resistencia de la conexión perno. Revista Cubana de Ingeniería, v. VII, p. 12-18, 2016.

download: 12-18 Influencia del uso.pdf . En este trabajo se evalúa el impacto de la utilización de los métodos simplifi cados de determinación de la evolución de las temperaturas en la resistencia de la conexión tipo perno a elevadas temperaturas, en vigas compuestas de acero y hormigón sin revestimiento y con revestimiento contra incendio. Para esto se realizan comparaciones entre la resistencia de la conexión tipo perno cuando se determina la temperatura en el ala superior del perfil por el método simplificado y la obtenida mediante la utilización del método de elementos fi nitos. Se pudo demostrar que cuando se determina la temperatura en el ala del perfil por el método simplificado y el ala superior del perfi l de la sección compuesta presenta un factor de masividad elevado, se subestima en gran medida la resistencia de la conexión lo cual se hace más marcado cuando en las expresiones de diseño predomina el fallo del conector.

12-18 Influencia del uso.pdf

Leia Mais

JACINTHO, Ana Elisabete P. G. A. ; SILVA, V. P. ; REQUENA, João Alberto Venegas ; LINTZ, Rosa C. C. ; BARBOSA, Luísa Andréia Gachet ; PIMENTEL, Lia Lorena . Analysis of composite steel and concrete columns at high temperatures. Fire and Materials, v. 40, p. 305-317, 2016.

Papers (geral)


SILVA, V.P.; COSTA, Carla Neves ; MELÃO, Arthur . Procedure for decreasing the required time for fire resistance of the multistory buildings. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 10, p. 1141-1162, 2017.

download: 887-6167-4-PB.pdf .The Brazilian standard ABNT NBR 15200: 2012 details a procedure for decreasing the required time of fire resistance in buildings with good fire safety characteristics. It called equivalent time method. This name can confuse the less habituated to the fire safety area, because the Brazilian procedure is not equal to the original equivalent time method, European. The purpose of this paper is to discuss the equivalent time method, to detail the origins of the Brazilian method and present their limitations no explicit in the Brazilian standard. Some unknown aspects of most researchers or technical means are presented. It should be highlighted the abundant bibliography presented to aid the understanding of a seemingly simple issue, but it incorporates many concepts of fire safety, not always understood by the users.

887-6167-4-PB.pdf

Leia Mais

SILVA, V. P.. On the buckling of steel members under axial compression. REVISTA DA ESTRUTURA DE AÇO, v. 5, p. 79, 2016.

O dimensionamento de barras de aço sob compressão centrada conforme a NBR 8800 de 1986 tinha por base as múltiplas curvas europeias. A base escolhida para a ABNT NBR 8800:2008, no entanto, foi o AISC, norte-americano. Apesar de ambas levarem a resultados similares, a formulação é diferente. Neste trabalho apresenta-se uma detalhada e didática introdução sobre o comportamento dessas barras de aço. São abordados tópicos relacionados à teoria clássica de flambagem, que é válida somente para barras ideais, e o efeito de imperfeições geométricas e do material. Apresenta-se, também, um estudo simplificado da estabilidade do equilíbrio de barras com rigidez concentrada. Inclui-se uma dedução da curva para dimensionamento de barras constituídas por materiais elástico-lineares e a comparação entre resultados obtidos de várias curvas.

http://www.cbca-acobrasil.org.br/lib/php/download-revista-cientifica.php?arq=101468_sobre_a_instabilidade_de_barras_de_aco_sob_compressao.pdf


Leia Mais

PIERIN, I. ; SILVA, Valdir Pignatta ; ROVERE, Henriette Lebre . Thermal analysis of two-dimensional structures in fire. REVISTA IBRACON DE ESTRUTURAS E MATERIAIS, v. 8, p. 25-36, 2015.

The structural materials, as reinforced concrete, steel, wood and aluminum, when heated have their mechanical proprieties degraded. In fire, the structures are subject to elevated temperatures and consequently the load capacity of the structural elements is reduced. The Brazilian and European standards show the minimal dimensions for the structural elements had an adequate bearing capacity in fire. However, several structural checks are not contemplated in methods provided by the standards. In these situations, the knowledge of the temperature distributions inside of structural elements as function of time of exposition is required. The aim of this paper is present software developed by the authors called ATERM. The software performs the thermal transient analysis of two-dimensional structures. The structure may be formed of any material and heating is provided by means of a curve of temperature versus time. The data input and the visualization of the results is performed thought the GiD software. Several examples are compared with software Super TempCalc and ANSYS. Some conclusions and recommendations about the thermal analysis are presented.

http://www.revistas.ibracon.org.br/index.php/riem/article/view/590/602


Leia Mais

SILVA, V.P.. Segurança das Estruturas em Situação de Incêndio. Uma Visão da América Latina. Revista FLAMMAE, v. 1, p. 180-185, 2015.

Foram pesquisados alguns dos mais importantes países da América Latina e são apresentadas informações sobre as exigências sobre estruturas em situação de incêndio.

http://docs.wixstatic.com/ugd/08765e_c7c4f57be82242dc8fcb8b72c5429269.pdf

Leia Mais

LUBAS, Paulo Henrique ; SILVA, Valdir Pignatta . Dimensionamento de pilares mistos de aço e concreto. Construção Metálica, v. 108, p. 40-43, 2013.

PIERIN, I. ; SILVA, Valdir Pignatta ; ROVERE, Henriette Lebre . Critical forces and bending moments of cold-formed steel. REVISTA DA ESTRUTURA DE AÇO, v. 2, p. 21, 2013.

SILVA, Valdir Pignatta. Cálculo da Largura Efetiva de Elementos Comprimidos Enrijecidos conforme AISI/86. Revista Construção São Paulo, São Paulo, p. 61-64, 1988.

SILVA, Valdir Pignatta. Cálculo de Estribos para Resistir a Esforços Provenientes de Forças Cortantes em Vigas, na Flexão Simples. Revista Construção Pesada, São Paulo, n.117, p. 65-74, 1980.

SILVA, Valdir Pignatta. Cálculo de Flechas em vigas Tê de Concreto Armado. Revista Estrutura, Rio de Janeiro, v. 90, n.80, p. 73-77, 1980.

SILVA, Valdir Pignatta. Cálculo de Estribos. Revista Estrutura, Rio de Janeiro, v. 88, n.88, p. 37-42, 1979.

Teses


Silva, V. P. Estruturas de aço em situação de incêndio, Tese apresentada à Escola Politécnica da USP. 1997

In this Thesis a study about the behavior of steel structures on fire was carried out. Comments about fire models (temperature-time curves of hot gases) are made and the expressions to determine the thermal action on the structures and its effect, the temperature on steel, are derived. The influence of load fire, opening factor (ventilation) and section factor (massivity factor) is discussed. Stress-strain curves of steel, including the creep phenomena, under high temperature are presented. A comparison between the safety criteria for the accidental situation of structures in fire, based on Brazilian and European Standards, is made. A simplified method of steel structures fire design is recommended and the influence of geometrical and material non linearities and thermal deformation are analyzed.

Steel structures in fire

TESEcompleta.pdf

Leia Mais

Silva, V. P. Flambagem Lateral de Vigas de Aço Em Regime Elástico-Linear. Dissertação (mestrado) apresentada à Escola Politécnica da USP. 1992

Neste trabalho, foi deduzida a equação geral para a determinação do momento crítico à flambagem lateral de vigas com seção monossimétrica em regime elástico e analisados diversos casos particulares. Foi feita uma comparação às recomendações da Norma Brasileira (ABNT NBR 8800:1986 e normas norte-americanas AISC/LRFD/1986 e AISI/1986). Foram indicadas e comentadas as limitações no uso das expressões presentes nessas Normas. Foi incluído também um resumo dos principais resultados numéricos para uso no cálculo expedito do momento crítico em esquemas estruturais convencionais.

Lateral-torsional buckling of steel beams in elastic linear regimen

dissertacao-Valdir-1992.pdf

Leia Mais

Gabriela Bandeira de Melo Lins de Albuquerque. Análise numérico-experimental de vigas de concreto armado com restrições axial e rotacional em situação de incêndio. 2018. Tese (Doutorado em Engenharia Civil (Engenharia de Estruturas)) - Escola Politécnica da Universidade de São Paulo,. Orientador: Valdir Pignatta e Silva.

Reinforced concrete beams are submitted to thermal deformations when exposed to fire. The lengths of the spans elongate, a fact that triggers the horizontal displacement of their supports, and they begin to bend sharply, resulting in their rotation. If these deformations are hindered by the support conditions of the element or by surrounding structural elements, for instance, additional efforts will act on the beams in order to modify their performance when facing the action of fire. Studies have pointed out that the effects of such efforts may be beneficial to the fire resistance of the beams; however, in the few researches focused on the experimental analysis of this issue, the restraints were admitted only in an isolated way, i.e., the beams were either submitted to axial or to rotational restraints. Their coupled effect, more representative of what occurs in reality, and the consideration of different stiffness levels imposed on the deformations, were evaluated in numerical investigations, without suitable experimental data for validating the results, though. In this PhD Thesis, the performance of concrete beams was evaluated experimentally by performing bending tests on full-scale elements under different support conditions: unrestrained, only with axial restraints and with both axial and rotational restraints. Regarding the restrained elements, two levels of axial and rotational stiffness were analyzed, 0.02 and 0.04EA/l; 1 and 2EJ/l. There were also reference tests on simply supported beams at ambient temperature to check the load-bearing capacities and failure modes. The experimental data obtained for different beam static schemes still motivated the conception of numerical models that would be representative of their behavior. With the aid of the DIANA software, which is based on the finite element and displacement methods, beam models to represent beams tested at ambient temperature and in fire conditions were created. These models were implemented considering several properties that characterize the nonlinear behavior of the materials and led to good correlations when their results were compared to those obtained in the laboratory. The main conclusion of this experimental and numerical study was that the fire resistance of RC beams always increases when any type of restraint (axial or axial plus rotational) is introduced. In addition, by fixing the rotational stiffness, the beams with higher axial stiffness level presented higher fire resistance than those with the lower level. The same was observed by fixing the axial stiffness and varying the rotational stiffness. Beams in which the combined effect of the restraints was admitted led to higher resistances than those with only axial restraint. For most of the studied situations, the increases of the resistances showed to be significant when confronted with the ones for unrestrained beams. Thus, it was confirmed that the standard simplified methods that allow the non-consideration of these effects during the fire design of the RC beams lead to conservative results. The numerical and experimental results presented herein may aid in the conception of alternative tools that allow applying restraint effects to design.

http://www.teses.usp.br/teses/disponiveis/3/3144/tde-29082018-085805/publico/GabrielaBandeiradeMeloLinsdeAlbuquerqueCorr18.pdf

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Jorge Saúl Suaznábar Velarde. Análise dos efeitos das interações entre pilares e vigas de estruturas de concreto armado em situação de incêndio. 2018. Tese (Doutorado em Engenharia Civil) - Escola Politécnica da Universidade de São Paulo. Orientador: Valdir Pignatta e Silva.

Reinforced concrete columns are very important elements in structures in fire. Their collapse may affect very much the equilibrium and stability of the complete structure. In structural elements analysis is very important to consider the interaction with other elements of the structure. However, the behavior of the structural elements is usually considered as isolated, without considering any interaction. There are many studies of reinforced concrete columns in fire situation considering them as isolated. However, there are too few considering the interaction with beams and frames that are typical from buildings. This doctoral thesis studies reinforced concrete columns in fire situation considering the interaction with the structure. In the analysis, material non-linearity, concrete cracking, and mechanical properties of concrete and steel variation as a temperature function, e.g. strength and young’s module loss and the stress-strain curves varying with temperature are considered. In addition, variations of the thermal properties are considered, e.g. specific heat, thermal conductivity, and thermal elongation. Some structures configuration combined with the concepts given before are analyzed with specialized software, including some own codes.

http://www.teses.usp.br/teses/disponiveis/3/3144/tde-03102018-144124/publico/JorgeSaulSuaznabarVelardeCorr18.pdf

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Igor Pierin. A instabilidade de perfis formados a frio em situação de incêndio. 2011. 0 f. Tese (Doutorado em Engenharia Civil) - Escola Politécnica da Universidade de São Paulo. Orientador: Valdir Pignatta e Silva.

The use of cold-formed steel profile in construction has increased because of its high efficiency, expressed as the ratio between load capacity and weight, and ease of manufacturing, characterized by the possibility of production of elements with different cross sections. Due the high slenderness ratio of the sections elements, the design of these profiles, either at room temperature or in case of fire, is determined by local, distortional and global buckling phenomena. The aim of this Thesis is to develop computational tools that allow the assessment of the structural behavior of cold-formed steel columns in fire. For this purpose, two softwares are developed. The first one, called ATERM, allows determining the temperature field under transient analysis of two-dimensional structures formed by any material, subjected to any time-temperature fire curve, and is based on the finite element method. This software interacts with another program, ATERM-DIM, used for plastic design of lateral restrained beams steel in fire. Results of ATERM are compared to those obtained from the Swedish software Super Tempcalc. The second program, named INSTAB, can perform linear and nonlinear stability studies of cold formed profiles, taking into account the local, distortional and global buckling, by means of the splines finite strip method for elastofragile material, considering the reduction of mechanical properties caused by the increase in temperature. Resistant values obtained by the INSTAB software are compared with results from the commercial finite element program ANSYS, which considers the plastic behavior of the material and also with results obtained by means of a simplified method for design of cold-formed profiles in fire, proposed by the author for the Brazilian fire standard. This comparison allows analyzing the effect of elastoplasticity in columns of cold-formed steel. Another objective of this study is to provide background for the development of procedures for the structural analysis of cold formed profiles in fire.

https://www.google.com/url?q=http://www.teses.usp.br/teses/disponiveis/3/3144/tde-12032012-123926/publico/Tese_Igor_Pierin.pdf&sa=U&ved=0ahUKEwjx4PKry_TeAhXMHZAKHa4WAPMQFggHMAE&client=internal-uds-cse&cx=011662445380875560067:cack5lsxley&usg=AOvVaw33r9NO9k0g_FpX7famMOKs

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Macksuel Soares de Azevedo. Segurança das estruturas de aço externas a edificações em situação de incêndio, sem revestimento contra fogo. 2009. Tese (Doutorado em Engenharia Civil) - Escola Politécnica da Universidade de São Paulo, Orientador: Valdir Pignatta e Silva.

Steelworks outside a building in fire situation are exposed to radiation that come from the windows in the façade and from flames, as well as the convection of hot gases. The absorption of the heat for the element depends on its placement in relation to the openings. Margaret Law, based on many experimental data about fire in buildings, estimated the external heat transfer to steel elements and the maximum temperature value reached by them. The Eurocode 1, part 1.2 (2002) and Eurocode 3, part 1.2 (2003) have adopted the method previously mentioned with small modifications. The Brazilian standard ABNT NBR 14323:1999 - “Dimensionamento de estruturas de aço de edifícios em situação de incêndio – Procedimento” (Steel structures fire design – Procedure) allows employment proposed by Eurocodes 1 and 3 without detailing it. A software, ExteelFire, to determine the maximum temperature on external steel structures of buildings in fire, based on Margaret Law’s method was elaborated in this work. Results from ExteelFire and the values determined by numerical analysis, with software CFD (CFD - Computational Fluid Dynamics) Smartfire and Super Tempcalc (thermal analysis) have been compared. Furthermore, results from ExteelFire and values determined in tests in fire compartment, in natural scale (Dalmarnock experiment and Mittal Steel Ostrava experiment) have also been contrasted. In this work it was also applied ExteelFire to commonly used situations in civil construction, showing conditions where the thermal protection can be excluded.

https://www.google.com/url?q=http://www.teses.usp.br/teses/disponiveis/3/3144/tde-11082010-171812/publico/Tese_Macksuel_Soares_de_Azevedo.pdf&sa=U&ved=0ahUKEwjpob3jzPTeAhWEiJAKHRaeCQIQFggFMAA&client=internal-uds-cse&cx=011662445380875560067:cack5lsxley&usg=AOvVaw1zoBrqbf3TloPwPRkWvAAx

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Carla Neves Costa. Dimensionamento de elementos de concreto armado em situação de incêndio. 2008. Tese (Doutorado em Engenharia Civil) - Escola Politécnica da Universidade de São Paulo. Orientador: Valdir Pignatta e Silva.

The thermal and mechanical properties of building materials are reduced at high temperatures, and the structural resistance of reinforced concrete buildings, as well. If the means of active protection are not efficient the fire will develop and the consequential increase in temperature can take an important role on the local failure of a single member or the progressive collapse of the building. The structural design must take into account the possibility of a fire happening as an accidental action during the lifetime of the building, aiming mainly at the protection of the users lives. This doctoral thesis aims to contribute to the development of the technical references in Portuguese about the fire design of reinforced concrete structures, to stimulate further researches and afterwards standard reviews related to the structural design in fire of reinforced concrete buildings. The work reviews the heat effects on the thermal and mechanical properties of the materials and the consequential impact on the structural behaviour of reinforced concrete buildings, the calculation methods available in the international technical reference for the fire design of reinforced concrete structures and presents a proposal of an optimized simplified calculation method for the members under simple bending or composed axial-moment load, considering the geometric and concrete characteristics very usual in Brazil.

http://www.teses.usp.br/teses/disponiveis/3/3144/tde-04092008-155911/pt-br.php

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Thiago Menezes de Andrade. Compartimentação de edifícios para a segurança contra incêndio. 2018. Dissertação (Mestrado em Engenharia Civil) - Universidade de São Paulo, . Orientador: Valdir Pignatta e Silva.

Methods for designing a building with adequate fire safety are poorly studied and applied in Brazil. This lack of study is even more present in the compartmentation subject, much-undeveloped topic and not yet standardized by ABNT. The compartmentation, especially the vertical, is critical to life safety, since it minimizes the spread of fire between building floors, and to validate the standardized procedures for structures in fire situation, because an important hypothesis of design methods is the vertical compartmentation. Currently the requirements of compartmentation are only present in the Technical Instructions of the States Fire Department, varying from state to state. This paper presents a study on compartmentation, its influence on the fire safety of buildings and a comparison of the vision of some countries of four different continents on this subject. After a comparative study of the vision and standardization between countries such as Brazil, Portugal, England, Hong Kong and the United States, computer simulation based on the theory of the finite volumes and computational fluid dynamics were carried out in order to try to check thoroughly the influence of compartmentation requirements in a real fire spread. Ultimately, the main focus of this work is to demonstrate that the Computational Fluid Dynamics (CFD) can be used in order to assist the study of fire, in order to allow a more in-depth analysis of the subject. Keywords: fire, compartmentation, standardization, fire resistance, computational fluid dynamics, FDS, computational modeling.

http://www.teses.usp.br/teses/disponiveis/3/3146/tde-24092018-090530/publico/ThiagoMenezesdeAndradeCorr18.pdf

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Lucas Romagnoli. Análise de vigas mistas de aço e concreto semicontínuas em situação de incêndio. 2018. Dissertação (Mestrado em Engenharia de Estruturas) - Universidade de São Paulo, . Orientador: Valdir Pignatta e Silva.

A study will be carried out on the behavior of simply supported, full interaction composite steel and concrete beams composed by compact profiles in fire situation. Despite being designed as simply supported, the main idea is to consider, in the fire situation analysis, the moment resistance capacity reserve on the beam supports, usually neglected during room temperature design, due to the upper longitudinal reinforcement present in the concrete slab, being possible to dispense fireproof coating in these elements. First, room temperature design procedures of composite beams will be approached in order to explain the structural behavior of this type of elements, providing a basis for subsequent thermal analysis. The thermal analysis will be carried out, in a first stage, by simplified methods according to design procedures and adopting simplifying hypotheses in which indirect stresses caused by thermal expansion and thermal gradient are neglected, being possible to apply those concepts in structural design offices. In a second step, thermal stress analyses were performed with aid of numerical models to study the structural behavior and collapse time of the beam. The results were sufficient to validate the fire resistance time values found by the simplified analysis following design methods. As a conclusion, the structural capacity increase of the beam, provided by the adoption of the composite connection at the support in case of lighter steel profiles usually chosen to be used as buildings floor beams, was sufficient for situations of standard fire resistance requirements between 15 min and 21 min. Analyzes have shown that it is not possible to justify the absence of fire resistant coating for standard fire resistance requirements of 30 min or higher. Lower times can be adopted according to the so-called equivalent time method, limited to 15 min, which are more common for small buildings. Key-words: fire; steel structures; composite steel and concrete structures; thermal structure analysis; semicontinuous beams.

http://www.teses.usp.br/teses/disponiveis/3/3144/tde-21092018-135055/publico/LucasCosciaRomagnoliCorr18.pdf

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Arthur Ribeiro Melão. Sobre perfis I de aço em situação de incêndio paramétrico. 2016. Dissertação (Mestrado em Engenharia Civil (Engenharia de Estruturas)) - Universidade de São Paulo, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Orientador: Valdir Pignatta e Silva.

The issue of this Master Dissertation is the design of steel beams and columns in fire situation. The formulation for the design in fire was presented, explaining its origin. The main objective is the development of a computational tool, which was called AçoInc, able to calculate the resistances of steel elements at room temperature according to ABNT NBR 8800:2008 and in case of fire according to ABNT NBR 14323:2013. The temperature of the steel element in fire is also obtained through the AçoInc, following the heat transfer model of ABNT NBR 14323:2013 and basing on fire curves. These curves are the standard fire curve associated with the required fire resistance time and parametric curves for natural fire model of Eurocode 1 (2002). With the support of spreadsheets, some studies were performed. The first one is probabilistic study of failure of column and beam in fire situation considering the parametric fire and by means of the Monte Carlo method. Other study is parametric sensitivity analyses, which were performed to verify how the resistances are influenced by the dimensions of cross section, the variables of the natural fire and the properties associated with heat transfer. For this study, in addition to spreadsheets, we used the Software Statgraphics Centurion XV (2007), which contains resources of statistical analysis. Applying the spreadsheets, the equivalence between parametric curves and fire standard curve in the obtention of the steel temperature in the fire situation was verified. For the use of parametric fire, partial factors, based on the equivalent time method detailed on ABNT NBR 14323:2013 were proposed. At last, with the assistance of spreadsheets, simple non-computational tools were created for determining the critical temperatures for columns and beams in some constructive situations of practical interest. Some conclusions from these studies are that the steel temperature is the most important parameter in determining the resistance of steel structures in a fire situation, that the current formulation for parametric fire modeling leads to a variation of the fire temperature in function of the opening factor with undesirable discontinuity and that the data found in the international literature about probability of fire and flashover lead to divergent values of structural failure probability.

http://www.teses.usp.br/teses/disponiveis/3/3144/tde-02122016-090138/publico/ArthurRibeiroMelaoCorr16.pdf

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Leila Cristina Santos Cordeiro. Sobre o dimensionamento de lajes mistas de aço e concreto em situação de incêndio. 2014. Dissertação (Mestrado em Engenharia Civil) - Universidade de São Paulo, . Orientador: Valdir Pignatta e Silva.

The Brazilian standard ABNT NBR 14323:2013 presents a method for the composite slabs fire design. However, it doesnt include the effect of the slab behaving as a membrane. Using the theory of plates for large displacements, the research establishes that high temperatures can induce a considerable tensile membrane action, assisting in the safety of the slab in fire. In developing a tool for the analytical method composite slabs fire design, some studies were made to analyze the behavior of tensile membrane at high temperatures. The most popular analytical method is the Baileys method. In this study, analysis of the Baileys methods, the Brazilian standard and the Vulcan and MACS+ software were performed and the results were compared. As expected, the results were similar. Still, in this work, there have been some numerical studies employing the finite element method, using the computer program Vulcan, and results were compared between the Baileys method and Vulcan. An investigation about possible simplifications of the formulation presented by Brazilian standard were also developed.

http://www.teses.usp.br/teses/disponiveis/3/3144/tde-29042015-163950/publico/DISSERTACAO_Leila_Cordeiro.pdf

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Hellen Reis Mourão. Sobre o comportamento das vigas de aço, com flambagem impedida, em situação de incêndio. 2004. 0 f. Dissertação (Mestrado em Engenharia Civil) - Universidade de São Paulo, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Orientador: Valdir Pignatta e Silva.

Steel structures strength is reduced at high temperatures. The aim of this work is to analyze the behavior of supported and fully fixed end beams at high temperature, considering: several load levels, uniform temperature on the beam and thermal gradient through the cross section. The displacements, loads and reaction efforts in accordance to the temperature variations will be presented, taking into account the resistance decrease and the strain amplification at elevated temperatures. The analysis has been carried out by means the computer program ANSYS® v. 6, using the “beam-24” fine element. It was considered the non-linear effects of the geometry and the material of the structure, besides the stress-strain diagram in high temperature to many thermal levels. The thermal properties of the steel adopted in the structural modeling of the steel beams are given in the Brazilian Standard NBR 14323 (1999) – “Dimensionamento de estrutura de aço de edifícios em situação de incêndio” (“Steel structures design of buildings in fire conditions”).