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Experimental assessment of the ductility of extended end plate connections

Coelho, Ana M. Girão; Bijlaard, Frans S. K.; Silva, Luís Simões da
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
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45.71%
An experimental investigation of eight statically loaded extended end plate moment connections was undertaken at the Delft University of Technology to provide insight into the behaviour of this joint type up to collapse. The specimens were designed to confine failure to the end plate and/or bolts without development of the full plastic moment capacity of the beam. The parameters investigated were the end plate thickness and steel grade. The results show that an increase in end plate thickness results in an increase in the connection flexural strength and stiffness and a decrease in rotation capacity. Similar conclusions are drawn for the effect of the end plate steel grade, though no major variations in the initial stiffness are observed. The failure modes involved weld failure in two test specimens, nut stripping in four tests and bolt fracture in the remaining, always after significant yielding of the end plate and bolt bending. Comparisons of the joint ductility and the corresponding equivalent T-stub for the end plate side are drawn.; http://www.sciencedirect.com/science/article/B6V2Y-4CMHTWB-1/1/eb647759fdff588288cba2317fd86cfc

Avaliação da eficiência do teste precoce no melhoramento genético de soja; Evaluation of early generation testing effectiveness in soybean breeding

Carvalho, Agnaldo Donizete Ferreira de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 10/04/2008 PT
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36%
O teste em gerações precoces no melhoramento genético de plantas consiste em identificar e selecionar progênies promissoras em gerações iniciais de endogamia, tais como F2 ou F3, e com isso concentrar tempo e recursos somente em populações com potencial para gerar linhas puras superiores. Considerando a ocorrência de relatos conflitantes, este trabalho teve como objetivo avaliar a eficiência do teste precoce no melhoramento genético de soja, utilizando uma população derivada de um cruzamento biparental entre as linhagens 14 e 38, contrastantes para produção de grãos, e selecionadas do cruzamento entre os genitores PI-123439 e PI-239235. Os tratamentos consistiram de uma amostra de 100 progênies de cada tipo: F2:3, F3:4 e F4:5, que foram avaliadas em experimentos em látice 10 x 10 no ano agrícola 2005/6 na área experimental do Departamento de Genética da ESALQ/USP, em Piracicaba, SP. Os experimentos foram avaliados novamente no ano agrícola 2006/7, em dois locais: Piracicaba, SP e Anhumas, SP, utilizando, para isso, os bulks oriundos dos experimentos do ano anterior, isto é, progênies F2:4, F3:5 e F4:6,. A parcela experimental foi constituída de uma linha de 2 m de comprimento, espaçada de 0,5 m, contendo 35 plantas por parcela após o desbaste. Foram avaliados os seguintes caracteres: altura das plantas no florescimento (AF)...

Um estudo de caracterização e avaliação de critérios de teste estruturais entre os paradigmas procedimental e OO; A characterization and evaluation study of structural testing criteria between procedural and OO testing

Prado, Marllos Paiva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/05/2009 PT
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36.08%
O Teste de software é uma atividade de garantia da qualidade que tem por finalidade diminuir o número de defeitos do software. Esta atividade contribui para redução do custo de manutenção e para a melhora da qualidade do software, durante o processo de desenvolvimento. Isso tem motivado a investigação e proposta de estratégias, técnicas, critérios e ferramentas de teste para diferentes paradigmas de desenvolvimento, tais como procedimental, orientado a objetos e orientado a aspectos. Vários estudos experimentais têm sido desenvolvidos para avaliar e comparar critérios de teste. Grande parte desses experimentos foram realizados com programas construídos sob um mesmo paradigma ou desconsiderando a influência do mesmo sobre os resultados. Entretanto, é importante avaliar o impacto de um paradigma específico sobre a atividade de teste uma vez que alguns defeitos podem estar relacionados ao seu uso. Este trabalho apresenta um estudo experimental realizado para caracterizar e avaliar o custo de aplicação e a dificuldade de satisfação de critérios de teste, comparando dois paradigmas: o orientado a objetos e o procedimental. O estudo considera critérios de teste funcionais e estruturais e utiliza um conjunto de programas do domínio de Estrutura de Dados. Os termos e fases do processo de experimentação controlada foram usados...

Avaliação da efetividade dos critérios de teste estruturais no contexto de programas concorrentes; Investigating of the structural testing effectiveness in context of concurrent programs

Brito, Maria Adelina Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/11/2011 PT
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36.05%
A Engenharia de Software tem desenvolvido t[écnicas e métodos para apoiar o desenvolvimento de software confiável, flexível, com baixo custo de desenvolvimento e fácil manutenção. Técnicas e critérios de teste contribuem nessa direção, fornecendo mecanismos para produzir software com alta qualidade. Este trabalho apresenta um estudo experimental para avaliar o custo, eficácia e a dificuldade de satisfação (strength) dos critérios estruturais propostos para programas concorrentes. Esta avaliação foi conduzida usando oito programas implementados em MPI e utilizando a ferramenta de teste ValiMPI. Com base em taxonomias, defeitos foram injetados nos programas de modo a avaliar a eficácia dos critérios de teste em revelar os defeitos inseridos. Os resultados obtidos demonstraram o aspecto complementar dos critérios e informações sobre o custo e eficácia, que contribuíram para o estabelecimento de uma estratégia de teste incremental para aplicar os critérios de teste em uma boa relação custo-eficácia. Para concluir, os resultados indicam que os critérios de teste estrutural propostos para programas concorrentes em MPI são promissores e podem auxiliar a detectar defeitos nessas aplicações, melhorando a qualidade das mesmas; The software engineering has developed techniques and methods to help the software development reliable...

Avaliação do custo e efetividade dos critérios de teste estruturais no contexto de programas concorrentes com memória compartilhada; Evaluation of the cost. effectiveness and strength of structural testing criteria in the concurrent programs context with shared memory

Melo, Silvana Morita
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/10/2012 PT
Relevância na Pesquisa
36.08%
O teste de programas concorrentes e uma atividade desaadora, devido a fatores que não estão presentes em programas sequenciais, como comunicação, sincronização e não determinismo. Algumas técnicas de teste têm sido propostas para o contexto de programação concorrente, mas raramente sua aplicabilidade e avaliada por estudos teóricos ou experimentais. Este trabalho contribui nesse sentido, propondo e conduzindo um estudo experimental para avaliar o custo, eficácia e aspecto complementar dos critérios de teste estruturais para programas concorrentes no contexto de memória compartilhada, implementados usando o padrão PThreads (Posix Threads). A ferramenta de teste ValiPThread e usada para auxiliar a condução do experimento. Os programas usados no experimento foram selecionados de benchmarks, como o Inspect, Helgrind e Rungta. Esses benchmarks são comumente usados no estudo de técnicas de teste para programas concorrentes. Programas que resolvem problemas clássicos da programação concorrente também foram incluídos no estudo. Com base nos resultados obtidos foi definida uma estratégia de aplicação, considerando aspectos de custo e eficácia dos critérios de teste. Além disso, todo o material utilizado e gerado durante o experimento foi reunido em um pacote de laboratório...

Stresses analysis in semi-elliptic leaf spring and comparison with the SAE J788 (1982) norm

Daré Neto, Luiz; Bianchi, Eduardo Carlos; Fernandes, Odilson Coimbra; Filho, José Roberto Curitiba
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
45.78%
In this work are presented the values found with the experimental testing, in the semi-elliptic leaf spring, utilizing 24 strain gages, distributed in five leaves of springs; these values have been compared to the calculated values found with the application of Norm SAE J788 (1982). The results showed discrepancy between the values measured and calculated and that the Norm is not indicated to determine the actuating stress in any point of any leaf of the leaf spring, but due to its simplicity and quickness of the process it presents good precision for the pre-development of the product. Copyright © 2002 Society of Automotive Engineers, Inc.

Identification of steel bars immersed in reinforced concrete based on experimental results of eddy current testing and artificial neural network analysis

De Alcantara, Naasson
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 58-71
ENG
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35.98%
This paper presents an experimental research on the use of eddy current testing (ECT) and artificial neural networks (ANNs) in order to identify the gauge and position of steel bars immersed in concrete structures. The paper presents details of the ECT probe and concrete specimens constructed for the tests, and a study about the influence of the concrete on the values of measured voltages. After this, new measurements were done with a greater number of specimens, simulating a field condition and the results were used to generate training and validation vectors for multilayer perceptron ANNs. The results show a high percentage of correct identification with respect to both, the gauge of the bar and of the thickness of the concrete cover. © 2013 Copyright Taylor and Francis Group, LLC.

Experimental testing, numerical modelling and seismic strengthening of traditional stone masonry: comprehensive study of a real Azorian pier

Alexandre A. Costa; António Arêde; Aníbal Costa; João Guedes; Bruno Silva
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
45.83%
Stone masonry is one of the oldest building techniques used worldwide andit is known to exhibit poor behaviour under seismic excitations. In this context, this work aims at assessing the in-plane behaviour of an existing double-leaf stone masonry pier by experimental testing. Additionally, a detailed 3D finite element numerical analysis based on micro-modelling of the original pier is presented (fully describing the geometry and divisionof each individual elements, namely infill, blocks and joints) aiming at simulating the experimental test results. This numerical strategy can be seen as an alternative way of analysing this type of constructions, particularly useful for laboratory studies, and suitable for the calibrationof simplified numerical models. As part of a wider research activity, this work is further complemented with the presentation of an effective retrofit/strengthening technique (reinforced connected plaster) to achieve a significant improvement of its in-plane cyclic response which is experimentally verified in the results presented herein.

Experimental analysis on steel and lightweight concrete composite beams

Valente, Isabel; Cruz, Paulo J. S.
Fonte: Mainz Publicador: Mainz
Tipo: Conferência ou Objeto de Conferência
Publicado em //2005 ENG
Relevância na Pesquisa
45.71%
The present work describes the experimental tests on steel and lightweight concrete composite beams performed at University of Minho. The study involves tests on simply supported composite beams of 4.5 m span, with the same geometrical disposition, supports and materials. The geometrical configuration for the cross section and supports is identical for every beam, varying the shear connectors’ distribution and the loading conditions. Headed studs are used to provide the connection between the steel profile and the concrete slab. The parameters in study are the stud disposition and the load distribution. The main objective is to describe the composite beams behaviour, focused on its connection, and to analyse the contribution of the different components to the beams load and deformation capacity. All the tests explored the beams maximum load and deformation capacity and different types of failure were observed.; Investigation project Sapiens ECM/33067/99.; Fundação para a Ciência e a Tecnologia (FCT) - Praxis XXI.

Tube-jack testing for irregular masonry walls : first studies

Ramos, Luís F.; Sharafi, Ziba
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em 08/10/2010 ENG
Relevância na Pesquisa
45.96%
One of the most well-known non-destructive methods for inspection and diagnosis in historical masonry walls is the flat-jack testing. Although it gives qualitative and valuable results about the local stress level and the deformability of the masonry material, when testing on irregular masonry walls, or walls with larger stone units, experimental and practical problems might occur, leading to inaccurate or useless results. In addition, the testing apparatus is labor, with difficulties in sawing task. Another limitation is the difficulty to test multi-leaves walls. To overturn these problems and to achieve more reliable information, an enhanced type of jacks is proposed in the paper. The new testing system consists of tube-jacks instead of the usual flat-jacks. As part of the preliminary research, analyses with FE models to simulate the differences between the conventional and the enhanced method are presented in the paper. The advantages and disadvantages of both methods are discussed and further research steps are presented.

Biodiesel by-product as an admixture for cement-based materials : an experimental study

Alves, Inês Carlos
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Trabalho de Conclusão de Curso
Publicado em //2013 ENG
Relevância na Pesquisa
45.73%
Dissertação de mestrado integrado em Civil Engineering (área de especialização em Perfil de Estruturas e Geotecnia); The incorporation of admixtures or additions into concrete mixtures is extremely generalized owing to their ability to confer numerous advantageous effects on concrete. However, because admixtures are frequently expensive and may carry relevant ecological footprints, there is an increasingly higher necessity and interest in finding cheaper and more sustainable admixtures in otherwise useless by-products generated by industrial processes. Biodiesel production in one of such industries, which by-product is the crude glycerol that is produced in a 1:10 mass ratio in relation to biodiesel production, and it generally has 80%- 88% of purity, thus containing various impurities, such as ash, soap, chloride and residual methanol. In order to make crude glycerol a useful product for general industry processing, it is necessary to upgrade it to glycerol of high purity. Nonetheless, at intermediate levels of purity, crude glycerol might be usable for concrete industry. In fact, because of its physicalchemical properties and compounds, it is plausible to suspect that there might be a potential synergy between the crude purified glycerol with cement-based materials by applying this treated by-product to the mixture as an admixture. As such evaluation is not yet reported in the literature...

Tube-jack testing : regular masonry wall testing

Manning, Elizabeth; Ramos, Luís F.; Fernandes, Francisco
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2014 ENG
Relevância na Pesquisa
45.87%
Tube-jack testing is an enhanced non-destructive test method being developed at the University of Minho as an enhanced version of the traditional flat-jack test method. The tube-jack system consists of several tube-jacks, instead of flat-jacks, roughly aligned in holes drilled into the mortar joints, of the masonry to be tested, forming an equivalent flat-jack. The tube-jack system can be used similarly to the flat-jack system to test the mechanical properties of historical masonry during inspection and diagnosis of a masonry structure. In this paper the testing of the complete tube-jack system in a regular masonry wall is pre-sented. Several single tube-jack tests were performed in horizontal joints in a regular mason-ry wall, made of granite and cement-lime mortar, built in the laboratory for this purpose. The tests were studied to determine if they could accurately estimate the stress level in the masonry. A double tube-jack test was also performed to determine if this method could be an alternative to the double flat-jack test. Finally, these tube-jack tests were compared to single and double flat-jack tests performed next to the tube-jack tests in the same masonry wall. The results and conclusions of each of these tests are discussed and possible future improve-ments to the tube-jack system are presented.

Testing and modeling of a traditional timber mortise and tenon joint

Feio, A. O.; Lourenço, Paulo B.; Machado, José S.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
45.83%
The structural safety and behaviour of traditional timber structures depends significantly on the performance of their connections. The behaviour of a traditional mortise and tenon timber joint is addressed using physical testing of full-scale specimens. New chestnut wood and old chestnut wood obtained from structural elements belonging to ancient buildings is used. In addition, the performance of different semi and non-destructive techniques for assessing global strength is also evaluated. For this purpose, ultrasonic testing, micro-drilling and surface penetration are considered, and the possibility of their application is discussed based on the application of simple linear regression models. Finally, nonlinear finite element analysis is used to better understand the behaviour observed in the full-scale experiments, in terms of failure mode and ultimate load. The results show that the ultrasonic pulse velocity through the joint provides a reasonable estimate for the effective- ness of the assembly between the rafter and brace and novel linear regressions are proposed. The failure mechanism and load–displacement diagrams observed in the experiments are well captured by the proposed non-linear finite element analysis, and the parameters that affect mostly the ultimate load of the timber joint are the compressive strength of wood perpendicular to the grain and the normal stiffness of the interface elements representing the contact between rafter and brace.

Influence of the testing procedures in the mechanical characterization of adobe bricks

Silveira, Dora; Varum, Humberto; Costa, Aníbal
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
45.83%
A study of the influence of testing procedures in the mechanical characterization of adobe bricks traditionally used in Aveiro district, Portugal, was conducted. Cylindrical and cubic adobe specimens were subjected to simple compression tests, adobe bricks to flexural tests, and cylindrical adobe specimens to splitting tests. With these tests it was possible: (i) to collect more data to improve the knowledge of the mechanical behavior of adobe; (ii) to determine correlations between results obtained with different testing procedures; and (iii) to perform a rigorous characterization of the deformations suffered by adobe under compression, by measuring deformations directly on test specimens.

Biaxial seismic behaviour of reinforced concrete columns

Rodrigues, H.; Varum, H.; Arêde, A.
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
45.78%
The present work focuses on the assessment of the structural response of RC columns under bidirectional horizontal loads in three main streamlines. First, an experimental testing campaign was performed on rectangular columns, for different types of loading. Subsequently, the tested columns were simulated with different non-linear modelling strategies. Finally, a simplified hysteretic model is proposed for the representation of the non-linear response of RC members subjected to biaxial bending.

A study of a Gough-Stewart platform-based manipulator for applications in biomechanical testing.

Ding, Boyin
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
36.09%
This thesis investigates the development and application of a robotic system for in-vitro biomechanical testing to study the mechanisms leading to human joint injury and degeneration in an ethical and safe manner. Six degree of freedom (6-DOF) robotic-based systems, in particular Gough-Stewart platform-based systems, have been increasingly used in applications of biomechanical testing where 6-DOF mobility, large load capacity, and high stiffness and positioning accuracy are required from the testing machine. This study proposes a novel Gough-Stewart platform-based manipulator with ultra-high stiffness and accuracy for use in biomechanical testing and investigates its mechanism and control. Not only restricted to biomechanical testing, the proposed manipulator concept can also be applied to other robotic-based applications, particularly those requiring ultra-high accuracy positioning under large external loads (e.g machining). Four main features of the proposed manipulator are individually studied in this thesis: namely, stiffness and control of a non-collocated actuator-sensor mechanism, active preload control using actuation redundancy for backlash elimination, adaptive velocity-based load control of human joints for unconstrained testing...

2nd EFAST Workshop, Reliable Testing of Seismic Performance

MARAZZI Francesco; MOLINA RUIZ Francisco Javier
Fonte: Publications Office of the European Union Publicador: Publications Office of the European Union
Tipo: EUR - Scientific and Technical Research Reports Formato: Online
ENG
Relevância na Pesquisa
36.04%
The EFAST project consisted of a design study of a new major seismic testing facility in Europe that will be comparable with important testing installations that are now working or under construction in Japan, U.S.A., China and Taiwan. The presentations by invited experts during the 2nd EFAST Workshop, which was held by the end of the project, emphasized the basic idea that experiments are necessary because reliable engineering cannot still rely only on numerical predictions. The relation between the experimental research and the improvements of the buildings codes in the last decades has also suggested that a consistent experimental activity is fundamental for properly understanding and predicting the real behaviour of complex structural elements. Today in many fields, as in the assessment of nuclear facilities for example, more reliability is required in order to increase the safety, which leads to a newer impulse for experimental testing of components, subsystems, soil-structure interaction effects and so on. The necessity and characteristics of the available testing methods was reviewed with up-to-date examples and studies on aspects such as shaking table, pseudo-dynamic and hybrid testing methods, centrifuge facilities, scale models...

Experimental testing of entropic uncertainty relations with multiple measurements in pure diamond

Xing, Jian; Zhang, Yu-Ran; Liu, Shang; Chang, Yan-Chun; Yue, Jie-Dong; Fan, Heng; Pan, Xin-Yu
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/10/2015
Relevância na Pesquisa
45.83%
One unique feature of quantum mechanics is the Heisenberg uncertainty principle, which states that the outcomes of two incompatible measurements cannot simultaneously achieve arbitrary precision. In an information-theoretic context of quantum information, the uncertainty principle can be formulated as entropic uncertainty relations with two measurements for a quantum bit (qubit) in two-dimensional system. New entropic uncertainty relations are studied for a higher-dimensional quantum state with multiple measurements, the uncertainty bounds can be tighter than that expected from two measurements settings and cannot result from qubits system with or without a quantum memory. Here we report the first room-temperature experimental testing of the entropic uncertainty relations with three measurements in a natural three-dimensional solid-state system: the nitrogen-vacancy center in pure diamond. The experimental results confirm the entropic uncertainty relations for multiple measurements. Our result represents a more precise demonstrating of the fundamental uncertainty principle of quantum mechanics.; Comment: 8 pages, 5 figures, 2 tables

A Stability Formula for Plastic-Tipped Bullets Part 2: Experimental Testing

Courtney, Michael W.; Miller, Donald G.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/10/2014
Relevância na Pesquisa
45.78%
Part 1 of this paper describes a modification of the original Miller twist rule for computing gyroscopic bullet stability that is better suited to plastic-tipped bullets. The original Miller twist rule assumes a bullet of constant density, but it also works well for conventional copper (or gilding metal) jacketed lead bullets because the density of copper and lead are sufficiently close. However, the original Miller twist rule significantly underestimates the gyroscopic stability of plastic-tipped bullets, because the density of plastic is much lower than the density of copper and lead. Here, a new amended formula is developed for the gyroscopic stability of plastic-tipped bullets by substituting the length of just the metal portion for the total length in the (1 + L2) term of the original Miller twist rule. Part 2 describes experimental testing of this new formula on three plastic-tipped bullets. The new formula is relatively accurate for plastic-tipped bullets whose metal portion has nearly uniform density, but underestimates the gyroscopic stability of bullets whose core is significantly less dense than the jacket.; Comment: This is the second part of a paper originally published in two parts. The Part 2 draws from Part 1

An Experimental Study to Evaluate the Impact of the Programming Paradigm in the Testing Activity

do Rocio,Simone; de Souza,Senger; Paiva Prado,Marllos; Francine Barbosa,Ellen; Maldonado,José Carlos
Fonte: CLEI Electronic Journal Publicador: CLEI Electronic Journal
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2012 EN
Relevância na Pesquisa
36.03%
Several techniques and criteria are available to help conducting testing activity. The choice for one of them depends on different aspects, such as the time restrictions, effectiveness of the testing criteria or the features of the program under test. In this context, the programming paradigm might influence in the testing activity cost. This paper presents the results of an experimental study to characterize and evaluate the cost and strength of structural and functional testing criteria, comparing object-oriented and procedural programming paradigms. A set of 32 programs from the data structure domain was considered in this study. The main goals in the execution of this research were: i) to obtain initial results about the investigated questions; ii) to generate artifacts which can be used as basis to define and conduct further experimental studies; iii) to support training and teaching of software testing activity