Influência da geometria do martelo na determinação da força durante o ensaio de impacto Charpy-V

The instrumentation applied to the Charpy test machine allows the accompaniment of the specimen answer front the impact load, in form of a sign characteristically dynamic representative of the deformation process and it fractures of material tested. The main advantages of the rehearsal conventional Charpy: low cost, manufacturing sample facilities and simple handle the machine. With the instrumentation, the number of information regarding the process of fracture of the specimen increases. In this work discusses the influence of the hammer geometry in determination of the force during the process of specimen fracture submitted to the instrumented impact test Charpy-V. The purpose is obtaining a hammer, in conformity with Norma ISO 14.556, with great sensibility to register the force during the impact. Two geometries different from hammers were instrumented and rehearsed with material of low tenacity, in this case the steel ABNT 4140 in the condition of having normalized. It could be proven as larger the sensibility of the hammer, adult will be the effects of the shock waves in the strain gages of the transducer.

Bibliographical review of the used tyre in concrete

Due to the progressive increase of vehicles, the number of used tires is globally one of the serious environmental problems faced now. Therefore, several researches have being developed for its reuse. The use of tires' rubber in the concrete is a possible form of its a pplication, aiming a the recycling of this material and the improvement of certain properties, as tenacity, impact resistance, thermal and acoustic isolation. This article presents conclusions that several researchers obtained using the rubberized concrete. Thus there were researched several works enclosing the period of 1993 to 2003, presenting then the results of some characteristics of this concrete such as: physical properties in fresh and hardened state, mechanical properties and properties that remit the durability. The bibliographical revision has as objective to subsidize future researches that can contribute to improve the use of this concrete in civil construction.

Mortar added by tyre rubber residues: Characterisation in fresh and hardened state

Due to the progressive increase of vehicles, the number of used tires is globally one of the serious environmental problems faced now. Therefore, several researches have being developed for its reuse. The use of tires' rubber in the concrete is a possible form of its application, aiming at the recycling of this material and the improvement of certain properties, as tenacity, impact resistance, thermal and acoustic isolation. This article presents conclusions that several researchers obtained using the rubberized concrete. Thus there were researched several works enclosing the period of 1993 to 2003, presenting then the results of some characteristics of this concrete such as: physical properties in fresh and hardened state, mechanical properties and properties that remit the durability. The bibliographical revision has as objective to subsidize future researches that can contribute to improve the use of this concrete in civil construction.

Concreto de alto desempenho com adição de resíduos de borracha de pneu

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A influência da deformação plástica sobre a estabilidade mecânica da Austenita retida em aços 300M

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo do envelhecimento após deformação em um aço complex phase

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito no processo ECAP (EQUAL CHANNEL ANGULAR) na microestrutura e nas propriedades mecânicas de uma liga comercial de alumínio AA3104

Pós-graduação em Engenharia Mecânica - FEG

Influência dos elementos de liga no encruamento proveniente do processo de aplainamento nos aços hadfield

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos dos tratamentos térmicos de normalização, resfriamento rápido e alívio de tensões no aço ASTM A-516 grau 70, utilizado na fabricação de vasos de pressão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modos de aplicação de regulador de crescimento com diferentes densidades de plantas em cultivares de algodoeiro (Gossypium hirsutum L. var. latifolium Hutch.)

Pós-graduação em Agronomia - FEIS

Propriedades morfológicas e tensiométricas do peritônio de paca (Agouti paca, Linnaeus, 1766) a fresco, e conservados em glicerina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pontos polêmicos acerca do forrageamento de cupins subterrâneos (Isoptera: Rhinotermitidae): consumo de alimentos similares, reutilização de iscas e tunelamento em solos não uniformes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Foraging in subterranean termites (Isoptera: Rhinotermitidae): how do Heterotermes tenuis and Coptotermes gestroi behave when they locate equivalent food resources?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Treinamento em corrida de baixa intensidade: propriedades estruturais e mecânicas da epífise proximal do fêmur de ratas osteopênicas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise fractal de fraturas em regime linear elástico: modo I de carregamento

For the development of this graduate work of fractal fracture behavior, it is necessary to establish references for fractal analysis on fracture surfaces, evaluating, from tests of fracture tenacity on modes I, II and combined I / II, the behavior of fractures in fragile materials, on linear elastic regime. Fractures in the linear elastic regime are described by your fractal behavior by several researchers, especially Mecholsky JJ. The motivation of that present proposal stems from work done by the group and accepted for publication in the journal Materials Science and Engineering A (Horovistiz et al, 2010), where the model of Mecholsky could not be proven for fractures into grooved specimens for tests of diametric compression of titania on mode I. The general objective of this proposal is to quantify the distinguish surface regions formed by different mechanisms of fracture propagation in linear elastic regime in polymeric specimens (phenolic resin), relating tenacity, thickness of the specimens and fractal dimension. The analyzed fractures were obtained from SCB tests in mode I loading, and the acquisition of images taken using an optical reflection microscope and the surface topographies obtained by the extension focus method of reconstruction, calculating the values of fractal dimension with the use of maps of elevations. The fractal dimension was classified as monofractal dimension (Df), when the fracture is described by a single value, or texture size (Dt), which is a macroscopic analysis of the fracture, combined with the structural dimension (Ds), which is a microscopic analysis. The results showed that there is no clear relationship between tenacity, thickness and fractal values for the material investigated. On the other hand it is clear that the fractal values change with the evolution of cracks during the fracture process ... (Complete abstract click electronic access below)