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Determination of the numerical parameters of a continuous damage model for the structural analysis of clay brick masonry

Mangueira, Felipe Barbosa; Oliveira Neto, Luttgardes de; Azambuja, Maximiliano dos Anjos
Fonte: Universidade Federal de São Carlos (UFSCar), Dept Engenharia Materials Publicador: Universidade Federal de São Carlos (UFSCar), Dept Engenharia Materials
Tipo: Artigo de Revista Científica Formato: 1013-1021
ENG
Relevância na Pesquisa
46.45%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Models based on the continuous damage theory present good responses in representing the nonlinear behavior of reinforced concrete structures with loss of strength and stiffness of the material. However, damage theory is rarely employed in the analysis of masonry structures and numerical simulations are currently performed mostly by Finite Element Method formulations. A computational program was designed to determine the numerical parameters of a damage model of the physical properties of masonry components, solid clay brick and mortar. The model was formulated based on the composition of tensile and compressive surface strengths in the plane stress state. The numerical parameters, the corresponding curves of the activation surfaces and the evolution of the surfaces are presented. The results were fed into the computational program based on the Boundary Element Method (BEM) for the simulation of masonry walls, and two types of masonry were simulated. The results confirm the good performance of the model and the program based on the BEM.

An anisotropic linear elastic boundary element formulation for masonry wall analysis

Oliveira Neto, Luttgardes de; John Masia, Mark; Taguti, Yzumi; Carlos Rigitano, Antonio
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 434-440
ENG
Relevância na Pesquisa
46.51%
This work presents an application of a Boundary Element Method (BEM) formulation for anisotropic body analysis using isotropic fundamental solution. The anisotropy is considered by expressing a residual elastic tensor as the difference of the anisotropic and isotropic elastic tensors. Internal variables and cell discretization of the domain are considered. Masonry is a composite material consisting of bricks (masonry units), mortar and the bond between them and it is necessary to take account of anisotropy in this type of structure. The paper presents the formulation, the elastic tensor of the anisotropic medium properties and the algebraic procedure. Two examples are shown to validate the formulation and good agreement was obtained when comparing analytical and numerical results. Two further examples in which masonry walls were simulated, are used to demonstrate that the presented formulation shows close agreement between BE numerical results and different Finite Element (FE) models. © 2012 Elsevier Ltd.

Avaliação experimental dos metodos de prevenção de fissuras na interface alvenaria de vedação e pilar de concreto; Experimental analysis of methods of prevention of splitting in the fair-faced masonry and concrete column

Andre Penteado Tramontin
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 08/07/2005 PT
Relevância na Pesquisa
36.62%
As fissuras na interface alvenaria-estrutura são comuns e pouco se conhece a respeito da sua ocorrência, embora sejam freqüentes, especialmente as que aparecem na ligação alvenaria-pilar de concreto. O objetivo deste trabalho foi estudar a melhor técnica de ancoragem entre alvenaria-estrutura, avaliando sua eficiência no combate a esse tipo de fissura. Foram utilizados para a elaboração dos ensaios, além dos materiais usados na alvenaria de vedação (bloco cerâmico, argamassa etc), diferentes materiais de ancoragem (tela metálica eletrosoldada e barras de aço) e dispositivos de ligação (adesivo epóxi, pinos, arruelas e cantoneira), analisando-se assim o melhor conjunto do ponto de vista técnico. Foram feitos ensaios de caracterização dos materiais e de arrancamento à tração direta, até a ocorrência da primeira fissura visível a olho nu. Concluiu-se finalmente que a tela metálica eletrosoldada galvanizada malha 15 x 15 mm e diâmetro do fio 1,65 mm, sem cantoneira e com tratamento de chapisco com adesivo acrílico no pilarete foi a melhor técnica de ancoragem para a prevenção do aparecimento de fissuras na interface alvenaria de vedação e pilar de concreto; The splitting of the fair-faced masonry-structure are very usual but it is not wellknown the reason of its occurrence...

Experimental characterization of frp-masonry interface behaviour

Basílio, Ismael; Oliveira, Daniel V.; Lourenço, Paulo B.
Fonte: Zaklad Graficzny Politechniki Slaskiej Publicador: Zaklad Graficzny Politechniki Slaskiej
Tipo: Conferência ou Objeto de Conferência
Publicado em //2005 ENG
Relevância na Pesquisa
36.65%
Due to frp materials well known properties, restoration of historical heritage with such materials has become an attractive solution employed in structural rehabilitation, maintaining structural stability and avoiding unacceptable cracking or collapse. Specific knowledge concerning the structural behaviour of masonry structures strengthened with frp is quite scarce, which is a key issue when dealing with the strengthening of masonry constructions. This paper presents a set of experimental results on the characterization of the frp-masonry interface behaviour, carried out under direct shear loading. Brick masonry prisms were constructed and strengthened with frp strips bonded perpendicularly to bed joints. Different anchorage lengths and schemes, different frp materials and different masonry shapes were considered and studied. The experimental results are presented and discussed, particularly the variation of ultimate stress with the strengthening scheme and evolution of shear stress distribution along the anchorage length with stress level and strengthening scheme adopted.; Fundação para a Ciência e a Tecnologia (FCT) - POCTI/ECM/38071/2001.; Bettor MBT.; Mapei.; Mexican National Council for Science and Technology (CONACYT).

Experimental behaviour of three-leaf stone masonry walls

Oliveira, Daniel V.; Lourenço, Paulo B.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2006 ENG
Relevância na Pesquisa
36.59%
A major part of historical structures, currently in European urban centres, is built with stone masonry walls, often constituted by multiple leaves. A common typology encountered is the three-leaf stone masonry wall, which is characterized by a substantial presence of voids in the inner leaf and prone to brittle collapse mechanisms. Nevertheless, the knowledge of the mechanical behaviour of three-leaf masonry walls and guidelines for proper design and control ofthe interventions are limited. A comprehensive experimental study on the structural behaviour of three-leaf stone masonry walls has been planned at University of Minho, considering different strengthening techniques using GFRP (glass fibre reinforced polymer) materials, pozzolana-lime based mortar and lime-based grout. In the paper the first experimental results on materials and three-leaf stone masonry walls are presented and discussed.; Fundação para a Ciência e Tecnologia POCI/ECM/58987/2004

A brief overview on the retrofitting possibilities of masonry infill walls

Fangueiro, Raúl; Cunha, Fernando Eduardo Macedo; Vasconcelos, Graça; Abreu, S.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /11/2011 ENG
Relevância na Pesquisa
36.62%
This work presents a brief review on the seismic behavior on non-loadbearing masonry walls used as masonry infills. O Some examples of inefficient performance are shown based on information available of recent earthquakes. Additionally, a literature overview on the techniques for retrofitting existing masonry infills is provided. Finally, alternative braided reinforced composite materials are briefly described and pointed out as an alternative solution for retrofitting masonry infill walls.

Characterization and damage of brick masonry

Lourenço, Paulo B.; Hees, Rob van; Fernandes, Francisco; Lubelli, Barbara
Fonte: Springer Publicador: Springer
Tipo: Parte de Livro
Publicado em //2014 ENG
Relevância na Pesquisa
46.36%
Series : Building pathology and rehabilitation, ISSN 2194-9832, vol. 2; Clay brick is among the oldest used masonry materials. Given the technological evolutions since the industrial revolutions, old brick are much dif-ferent from todays’ bricks. This chapter provides a review on the chemical, physi-cal and mechanical properties of mortar, brick and masonry. In addition, a discus-sion on the possible causes of damage and the usage of expert systems in building diagnostics is also given.

Durability analysis of bond between composite materials and masonry substrates

Ghiassi, Bahman
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 16/12/2013 ENG
Relevância na Pesquisa
36.7%
Tese de doutoramento em Engenharia Civil; In recent years, composites materials have been increasingly accepted as effective strengthening technique for civil engineering structures, particularly in the case of reinforced concrete. The reliability of this technique, when externally applied, depends on the long-term bond behavior between these materials and the masonry substrate, but research in this area is still very limited. The main purpose of this thesis is to create a basis for a general approach to durability of masonry components strengthened with composite materials. As far as the research method is concerned, a combined experimental and numerical approach has been chosen. Through systematic testing, fundamental knowledge is developed concerning the physical and mechanical properties of the basic materials and the strengthened components under environmental degradation. The strengthened specimens are subjected to different hygrothermal conditions including water immersion and cycles of temperature with constant relative humidity. Non-destructive investigation tests are made for both un-exposed and exposed specimens. Analysis of the interface behavior for different exposure conditions are carried out and the results are discussed. Predictive models are also used for simulating the observed degradation and the reliability of each model is investigated in comparison to experimental results. The numerical studies are conducted at two levels. Firstly...

Caraterização da alvenaria submetida a impacto; Characterization of masonry submitted to impact

Dias, Abel
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Trabalho de Conclusão de Curso
Publicado em //2013 POR
Relevância na Pesquisa
46.71%
Dissertação de mestrado integrado em Engenharia Civil; A investigação das propriedades dinâmicas dos materiais tem vindo a aumentar, pois o efeito da velocidade de deformação influência a maioria dos materiais de construção. Apesar de já existirem muitos estudos acerca da influência da velocidade de deformação no aço e no betão, isso já não acontece com a alvenaria, existindo pouca informação na literatura. Torna-se por isso importante estudar o efeito da velocidade de deformação para uma modelação adequada e o dimensionamento de estruturas sob impactos de alta velocidade ou explosões. Pretende-se com este estudo perceber o comportamento dos materiais que constituem a alvenaria, tijolo e argamassa, para diferentes velocidades de deformação. Para esse efeito, será ser utilizada uma torre de queda, “Drop-Weight”, em provetes de tijolo, argamassa e alvenaria, com alturas e pesos distintos, introduzindo diferentes níveis de velocidades de deformação, desde os 4 s-1 até aos 199 s-1. O efeito da velocidade de deformação na tensão máxima, módulo de elasticidade, extensão de pico e energia de fratura em compressão será determinado através dos ensaios experimentais. Serão ainda estabelecidas relações empíricas para as propriedades do material sob a forma de fatores de incremento dinâmico (DIF).; The study of the dynamic properties of materials has increased in recent times. It is well established that the strain rate influences most of the materials used in construction. This effect on materials such as concrete or steel has been intensively investigated. However...

Direct sonic and ultrasonic wave velocity in masonry under compressive stress

Manning, Elizabeth; Ramos, Luís F.; Fernandes, Francisco M.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2014 ENG
Relevância na Pesquisa
46.76%
Sonic Pulse Velocity Testing and Ultrasonic Testing are widely accepted non-destructive testing techniques that can be used to investigate historical masonry structures. Sonic pulse velocity tests have been used with various set-up configurations to investigate the interior consistency of masonry walls and columns and to assess the effectiveness of grout injection; and ultrasonic tests have been used on masonry materials to estimate their elasticity. The velocity at which a wave passes through the masonry can be influenced by many variables such as the mechanical characteristics of the materials, arrangement of constituents, joints and voids. Due to the irregularity of historical masonry and the large number of variables that can influence the wave velocity, only qualitative results from these tests can be obtained. This paper presents the results of a laboratory test plan aimed at investigating the relationship between wave velocity and the variable of masonry compressive stress. Ultrasonic tests were performed on the constituent materials, granite and mortar blocks, while they were loaded in compression. Then direct sonic tests were performed on small masonry wallets constructed of the same materials while they were loaded in compression. Test results of the masonry are discussed in relation to those of the constituent materials.

Characterization of masonry behavior under high strain rates

Lourenço, Paulo B.; Pereira, João M.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2014 ENG
Relevância na Pesquisa
46.75%
The study of the dynamic properties of materials has increased in recent times. It is well established that the strain rate influences most of the materials used in construction. This effect on materials such as concrete or steel has been intensively investigated. However, similar studies on masonry materials such as clay bricks cannot be found in the literature easily. Understanding the strain rate effect on masonry materials is important for proper modelling and design of masonry structures under high velocity impacts, such as masonry parapets in bridges, or historic masonry subjected to blast loads, due to deliberate or negligent actions. This work aims at studying the behavior of masonry and its components in compression at different strain rates. A Drop Weight Impact Machine is used on historic clay brick, mortar and masonry specimens at different heights and weights introducing different levels of strain rate, ranging from 4 s-1 to 199 s-1 . The strain rate effect on the ultimate strength, Young’s modulus and strain at peak strength are determined from the experimental results. Empirical relations of dynamic increase factors (DIF) for these material properties are also presented. Finally, the study of a case study regarding the analysis of a historical structure in Portugal subjected to blast is presented and discussed for different scenarios.

A constitutive three-dimensional interface model for masonry walls subjected to high strain rates

Lourenço, Paulo B.; Hashemi, S.; Pereira, João M.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2014 ENG
Relevância na Pesquisa
46.71%
Investigation of the dynamic properties of construction materials is critical for structural engineering. The strain rate effect influences the properties of most constructions materials and this effect on materials such as concrete or steel has been intensively investigated. However, such studies on masonry materials are scarce. Understanding the strain rate effect on masonry materials is important for proper modelling and design of masonry structures under high velocity impacts or blast loads. The work, described in this paper, aims to study the behaviour of masonry at different strain rates. First, a drop weight impact machine is used at different heights and weights introducing different levels of strain rate. Then, a dynamic constitutive material interface model that includes an non-associated flow rule and high strain rate effects is proposed. The model capability is validated with numerical simulations of unreinforced block work masonry walls subjected to impact.

Security evaluation and design of structures subjected to blast loading

Pereira, João Miguel
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 27/06/2014 ENG
Relevância na Pesquisa
36.73%
Tese de doutoramento em Engenharia Civil; The work presented in this thesis was developed at the Department of Civil Engineering of University of Minho. This work involves experimental and numerical campaigns and intends to give a contribution for a better understanding of the effect of explosions. Blast loading is a subject of much actuality and considerable lack of expertise. Europe has never been so rich and safe, where the violent years of the first half of the 20th century lead to an unprecedented period of peace and stability. Despite the terrorist decades, e.g. connected to ETA and IRA in Europe, the attacks of Madrid (2004), London (2005) and worldwide (New York, Oklahoma, Mumbai) had a major psychological effect in the societies. Clearly, the understanding about the effect of blast loading in structures and their subsystems saves lives and reduces damage in buildings. The Buncefield explosion (2005) resulted in tremendous damage to the outlying area and huge fires involving 23 large oil fuel tanks. Experimental and finite element analyses are carried out for the static and dynamic response of lightweight metal boxes that are similar to the steel junction boxes on the site of this explosion. During the Buncefield Explosion Mechanism Phase I research...

A mechanical model for the seismic vulnerability assessment of old masonry buildings

Pagnini, Luísa Carlotta; Vicente, Romeu; Lagomarsino, Sergio; Varum, Humberto
Fonte: Techno Press Publicador: Techno Press
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.36%
This paper discusses a mechanical model for the vulnerability assessment of old masonry building aggregates that takes into account the uncertainties inherent to the building parameters, to the seismic demand and to the model error. The structural capacity is represented as an analytical function of a selected number of geometrical and mechanical parameters. Applying a suitable procedure for the uncertainty propagation, the statistical moments of the capacity curve are obtained as a function of the statistical moments of the input parameters, showing the role of each one in the overall capacity definition. The seismic demand is represented by response spectra; vulnerability analysis is carried out with respect to a certain number of random limit states. Fragility curves are derived taking into account the uncertainties of each quantity involved.

In-situ airbag testing of unreinforced masonry walls

Derakhshan, H.; Lumantarna, R.; Dizhur, D.; Ingham, J.M.
Fonte: International Masonry Society Publicador: International Masonry Society
Tipo: Conference paper
Publicado em //2010 EN
Relevância na Pesquisa
56.41%
A field testing programme was developed to investigate the out-of-plane behaviour of as-built unreinforced masonry (URM) walls of four different buildings. The buildings were between approximately 80 to 130 years old, and had different masonry materials and construction forms. The objective of the testing programme was to compare the as-built wall behaviour with that studied using laboratory-based samples and to provide data with which to evaluate current seismic assessment guidelines. In total, 10 tests were performed on seven URM walls, with the out-of-plane force being uniformly applied to the wall surface. Several tests were repeated with original and modified support conditions, and the results from different tests were analysed to identify the effect of different wall boundary conditions. In particular, the effects of a concrete ring beam used at the floor levels of a URM building and the effects of wall anchorage to the building diaphragms by means of grouted steel rods were investigated. A behavioural model previously obtained through laboratory testing was proven to be effective for prediction of the cracked wall behaviour. Out-of-plane wall resistance was compared to the appropriate seismic demand of each site, and the results of the comparison were used to evaluate the NZSEE 2006 out-of-plane wall seismic evaluation method. The study showed that the evaluation method was conservative in most cases...

Dynamic Increase Factor of Masonry Materials: Experimental Investigations

LARCHER Martin; PERONI Marco; SOLOMOS George; GEBBEKEN Norbert; BIEBER Philipp; WANDELT Jens; TRAN Ngoc Tho
Fonte: Federal Office of Bundeswehr Infrastructure, Environmental Protection and Services Publicador: Federal Office of Bundeswehr Infrastructure, Environmental Protection and Services
Tipo: Contributions to Conferences Formato: CD-ROM
ENG
Relevância na Pesquisa
46.71%
Masonry is used worldwide as an efficient and convenient building system. Masonry is made using bricks from terracotta, concrete, adobe or similar materials connected together by using mortar. Due to the recent threat levels knowledge of the behaviour of masonry materials under extreme dynamic loads has become very important. As a first step, it is necessary to establish whether the strength of these materials is increased with the strain rate that occurs for example under blast and impact loads. Thus the current investigation concerns the so-called strain rate effect for masonry bricks (adobe, terracotta, clinker) and for mortar under compression and tension using a Split-Hopkinson-Bar apparatus. The investigations are done at strain rates from about 80 up to 160 1/s. Static testing of the same materials has also been conducted for comparison. Results have shown that for masonry bricks the influ-ence of such strain rates on the tensile as well as on the compressive strength is negligible up to notable but smaller than for concrete. The strain rate effect of mortar is in the same range as that of concrete. Numerical investigations of blast loaded masonry walls will show the influence of the strain rate effect on such a structure.; JRC.G.5-European laboratory for structural assessment

Brick masonry identification in complex historic buildings

Barluenga Badiola, Gonzalo; Estirado, Fernando; Undurraga, Raimundo; Conde, Juan Felix; Agua, Fernando; Villegas, María Ángeles; García Heras, Manuel
Fonte: Mike J Forde Publicador: Mike J Forde
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.62%
This study is part of the Program “Geomateriales. Durabilidad y conservación de geomateriales del patrimonio construido” (S2009/MAT-1629) funded by the Comunidad de Madrid. The authors acknowledge the 13 professional support from Techno-Heritage (Network on Science and Technology for the Conservation of Cultural Heritage).; The aim of the study is to define a reliable interdisciplinary procedure for brick masonry identification in complex historic buildings, in order to enhance documentation, conservation and restoration issues, thereby putting into value the architectural heritage. The methodology integrates experimental data obtained through on site measuring and sampling with historical information. Direct measurements were obtained through photogrammetry and brick and mortar characterization tests and were used to relate stratigraphic units, fabric morphology and materials. The differences identified through morphological analysis and experimental results are double-checked with historical data, allowing a scientific interpretation, supported by experimental results and contrasted to historical information. This approach was used for the study of the brick masonry walls of the first College of the University of Alcalá (Madrid...

THE EVOLUTION OF THE DESIGN AND CONSTRUCTION OF MASONRY BUILDINGS IN THE UNITED STATES

Klingner, Richard E.
Fonte: Universidade de São Paulo. Instituto de Arquitetura e Urbanismo Publicador: Universidade de São Paulo. Instituto de Arquitetura e Urbanismo
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Avaliado Por Pares Formato: application/pdf
Publicado em 21/12/2012 ENG
Relevância na Pesquisa
46.53%
In this paper, the process used to develop building codes in the United States of America (USA) is summarized, with emphasis on masonry. Masonry materials used in the USA are discussed. Types of masonry construction in the USA are reviewed, addressing historical as well as modern masonry. Current non-structural and structural applications of masonry in the USA are reviewed. Historical development of masonry codes in the USA is summarized, with emphasis on the current Masonry Standards Joint Committee (MSJC) Code and Specification. Future trends in that document are predicted. The paper closes with a list of challenges to the masonry industry, and a list of focused research topics intended to meet those challenges.

SUSTAINABILITY: MASONRY’S CORNER STONE OR STUMBLING BLOCK?

Borchelt, J. Gregg
Fonte: Universidade de São Paulo. Instituto de Arquitetura e Urbanismo Publicador: Universidade de São Paulo. Instituto de Arquitetura e Urbanismo
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Avaliado Por Pares Formato: application/pdf
Publicado em 21/12/2012 ENG
Relevância na Pesquisa
36.74%
Sustainability has become an essential part of the construction industry within the last decade. Manufacturers have changed products and production methods in response to this clarion call. Masonry materials exhibit many attributes that make them excellent choices based on sustainability criteria. These are expounded on by masonry material manufacturers and their associations, but do they match the opinions of others in the construction industry? A review of current statements and publications from masonry material manufacturers’ websites provides an idea of what the masonry industry thinks of the sustainability of its products. In addition, websites of national associations representing masonry materials were examined to determine how the masonry industry is responding to the desire for more sustainable materials and buildings. Authors of papers at the World Sustainable Building Conference (SB11 Helsinki) provide access to their viewpoint of masonry as a sustainable material. This third-party collection represents how other members of the design and building industry view masonry. Those two viewpoints do not always coincide. The masonry industry faces several challenges to maintain its preeminence as the provider of sustainable materials.

Masonry components

Vasconcelos, Graça
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
46.53%
Masonry is a non-homogeneous material, composed of units and mortar, which can be of different types, with distinct mechanical properties. The design of both masonry units and mortar is based on the role of the walls in the building. Load-bearing walls relate to structural elements that bear mainly vertical loads, but can serve also to resist to horizontal loads. When a structural masonry building is submitted to in-plane and out-of-plane loadings induced by an earthquake for example, the masonry walls are the structural elements that ensure the global stability of the building. This means that the walls should have adequate mechanical properties that enable them to resist to different combinations of compressive, shear and tensile stresses.The boundary conditions influence the resisting mechanisms of the structural walls under in-plane loading and in a buildings the connection at the intersection walls are of paramount importance for the out-of-plane resisting mechanism. However, it is well established that the masonry mechanical properties are also relevant for the global mechanical performance of the structural masonry walls. Masonry units for load-bearing walls are usually laid so that their perforations are vertically oriented...