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Salvador, Brazil

Paggi R.A.,Federal University of Santa Catarina | Beal V.E.,SENAI CIMATEC | Salmoria G.V.,Federal University of Santa Catarina
International Journal of Advanced Manufacturing Technology | Year: 2013

Nanocomposites produced through the addition of carbon nanotubes to a polymeric matrix can improve the material properties. The mobility of the polymer chains is usually affected, and this is also related to the properties. Parts produced with the free-form fabrication process using the selective laser sintering (SLS) technique can be used in different high-performance applications as they do not require expensive tools for their manufacture. A specific field of interest is the aerospace industry which is characterized by a low production volume and the need for materials with a high performance to weight ratio. In this study, the free-form fabrication by SLS of parts made from nanocomposites comprised of polyamide 12 and multiwalled carbon nanotubes (MWCNTs) was investigated. Specimens were manufactured by SLS to identify the appropriate processing parameters to achieve high mechanical properties for aerospace applications. Laser energy density was adjusted to improve the material density, flexural modulus, and stress at 10 % elongation. Design of experiments was used to identify and quantify the effects of various factors on the mechanical properties. The results obtained showed that there was a limit to the amount of MWCNTs which could be mixed with the polyamide powder to improve the mechanical properties since a higher content affected the laser sintering process. © 2012 Springer-Verlag London Limited.

Lukacs L.,Ford Motor Company | Dassanayake M.,Ford Motor Company | Magalhaes R.,SENAI CIMATEC | Fontes C.,Federal University of Bahia | And 2 more authors.
International Journal of Automotive Technology | Year: 2011

The vehicular illumination system has undergone considerable technological advances in recent decades such as the use of a Light Emitting Diode (LED) Adaptive Front-lighting System (AFS), which represents an industry breakthrough in lighting technology and is rapidly becoming one of the most important innovative technologies around the world in the lighting community. This paper presents AFS control alternatives using fuzzy logic (types 1 and 2) to determine its operating parameters taking into consideration the road conditions in the state of São Paulo (Brazil). Fuzzy logic is a well-known extension of the conventional (Boolean) logic that enables the treatment of uncertainty present in the information through the definition of intermediary membership values between the "completely true" and the "completely false". This technique or modeling strategy is particularly important when a multi-parameter decision must be taken or the decisions are based on the human knowledge. The results show the potential of the methodology proposed and its suitability for light control providing safer nighttime driving. © 2011 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.

Machado S.L.,Federal University of Bahia | da Silva Paes Cardoso L.,SENAI CIMATEC | de Oliveira I.B.,Federal University of Bahia | de Faria Mariz D.,Petrobras | Karimpour-Fard M.,Iran University of Science and Technology
Transport in Porous Media | Year: 2016

This paper presents the results of permeability tests performed using different organic fluids and soil types in order to derive a model to predict soil permeability based on the soil water permeability values. The equation proposed by Nutting (Am Assoc Petrol Geol Bull 14:1337–1349, 1934), which uses the concept of intrinsic permeability, was extended in order to take into account the fluid and solid particle interactions. The properties of soil (plasticity index, (Formula presented.) , water permeability, (Formula presented.) and water saturation, (Formula presented.)) and fluid (density, (Formula presented.) , viscosity, (Formula presented.) , and relative dielectric constant, (Formula presented.)) were used in the model. The model results demonstrated good adherence to experimental values ((Formula presented.)). An error of about 6.4 times for the predicted soil permeability values was obtained, considering a confidence interval of 90 %. Experimental results extracted from technical literature were used to validate the model, using the same fitting constants as the experimental dataset of the authors. The model was able to capture the variation in the experimental results, although more than 10 % of the experimental results are located outside the confidence interval. © 2016, Springer Science+Business Media Dordrecht.

Andrade L.P.C.D.S.,SENAI CIMATEC | Ferreira C.V.,Federal University of Santa Catarina | Silva R.C.D.,Brazilian Technological Institute of Aeronautics | Gomes J.D.O.,Brazilian Technological Institute of Aeronautics
Procedia CIRP | Year: 2016

Industrial competitiveness has required from companies elevated quality standards, cost reduction and a high capacity of delivery. Within this scenario, an important industrial segment has a fundamental role: the tool and die industry. Tools and dies are resources that are fit to a specific task and are either produced as a single-unit batch or intermittently according to demand. Generally, this industrial segment has demonstrated low competitiveness, which in turn affects the performance of other production chains that rely on it. This is the case of the plastic transformation and metalworking industry, especially when forged and stamped parts are considered. This low competitiveness is a consequence of the deficient corporate structure found in these companies, which results in lack of compliance to quality standards, high costs and long delivery times. Besides the support given to current tool-and-die making clusters, a decentralization structuring project of this industry to other regions of Brazil is necessary. This need is illustrated by new automotive and other consumer goods production plants that have recently started operating in the northeast and central regions of Brazil. In order to contribute to this issue, this article proposes a strategic management model for the incubation process of industrial companies that comply with competitiveness standards required by current market demands. Besides the usual difficulties related to incubation and the creation of any enterprise, the tooling industry faces an additional obstacle related to investment in assets (buildings, machinery, and software). Therefore, a nucleation process based on an existing structure that will be shared by several companies is proposed (IDS-Industrial Development Structure). This structure shall be preferably established on an ICT (Brazilian denomination for Science and Technology Institutes) that shall contribute with professional training (tool and die making) and specialized services (e.g. metrology and tool tryouts). © 2016 The Authors.

De Oliveira Gomes J.,Brazilian Technological Institute of Aeronautics | De Almeida Jr. A.R.,Brazilian Technological Institute of Aeronautics | De Araujo Silva A.S.,Brazilian Technological Institute of Aeronautics | De Souza G.O.,SENAI CIMATEC | Nunes A.M.,Brazilian Technological Institute of Aeronautics
Journal of the Brazilian Society of Mechanical Sciences and Engineering | Year: 2010

Gas combustion represents the second principal way of electricity generation due to its disposal, and smaller dimension and pollution capacity when compared with diesel engines. The conversion of natural gas in electricity is made through gas turbines, and the rotors of its compressors are components that present significant difficulty in its manufacture. This paper focuses on an optimization approach of the 5-axis milling of titanium blisks, based on all the CAD/CAM modeling chain. Special interest is pointed to the systematic analysis of the correlation between machining parameter and surface integrity properties. The experimental part of this work is composed by two tests. The first one analyses the roughing operation of a TiAl6V4 impeller when using a tool radial engagement of 30% and 68%. The second is the simultaneous 5 axes milling of a test-piece, a TiAl6V4 integral bladed disk (BLISK) section containing five blades, with which the best milling strategy for this purpose is sought. The results showed the fundamental importance of CAD modeling in order to achieve simultaneous 5 axes milling without intermittent feed speed. It was observed that milling a blade following its parametric curves in the BLISK axis direction is the best choice, among the strategies proposed. Copyright © 2010 by ABCM.

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