Análise crítica de contratos técnicos como ferramenta para melhoria da gestão da manutenção

Currently, due to the highly competitive search among industries are becoming more tools for managing product that provides higher availability and therefore profitability. Maintenance as a strategic sector and of fundamental importance in business, it seeks to maximize availability and available resources, minimizing costs and waste, which directly impacts the company's results. The present work has as main objective the review of contracts for maintenance services for companies contracted by a chemical company in the Paraíba Valley, since most of its maintenance services are outsourced, and raise these contracts which are more critical and higher risk to the company's success, thus creating a tool for decision-making by maintenance managers in the act of seeking renewals or new contracts to provide services. As a result after drawing up a standard procedure for contracting of services and a better structuring of the same, we developed a method for the calculation of the criticality of the contracts and based on these calculations, charts were prepared which showed that the current scenario of maintenance contracts the company studied. Thus it is possible to evaluate the contracts which are most critical to the success or failure of the company studied, and also pave the way for further studies on how this criticality of a contract can affect the relationship, the contractor x contracted

Produção e caracterização físico-mecânica de painel de compensado de Eucalyptus sp. e adesivo PVA

Studies on new adhesives and resins for bonding wood and wood products are being conducted with the intention of improving their properties, taking into account a lower environmental impact. For this reason new formulations of polyvinyl acetate (PVA) adhesives have been developed, because they have no chemicals in its composition extremely polluting and harmful to health, as is the case of formaldehyde-based resins, which in turn are the most commonly used today for wood panels production. This study tested three different formulations of PVA adhesives, with different times and temperatures of pressing for the production of Eucalyptus sp. Plywood, coming up in satisfactory results with respect to shear strength at the bondline, which was higher for the PVA adhesives compared with urea-formaldehyde and phenol. The results of MOE and MOR were lower than those values of the panels produced with urea and phenol-formaldehyde, and the results of physical tests showed to be close to the panels produced with these same adhesives

Estudo de cargas térmicas de uma aeronave e dimensionamento de um sistema de ar condicionado

This work deals with the thermal load study of a fictitious aircraft as well as scaling, in terms of the airflow and temperature of the air conditioning system, for heating and cooling of the its internal environment, aiming the thermal comfort of occupants. The first part is presented the techniques and methods utilized for modeling different heat exchanges that occur in the aircraft and then allowed to calculate the total heat load and the airflow and temperature necessary to comply with the requirements of the thermal comfort. Techniques to determine the basic parameters, as convection coefficient and global coefficient of heat exchange, are also presented. The work aims to develop a program, using a computational tool, to automate the calculations so that facilitate this study. It also allows to be used for other airplanes just changing parameters and the control variables related to the specific project. Finally the program performs calculations for a fictitious airplane, to analyze its functionality and the influence of parameters involved in the temperature controls. The program allowed analyzing the sensitivity of portions of the thermal load and the corresponding parameters of influence, as well as the scaling of the air conditioning in terms of airflow and temperature. It was considered, despite the simplifications, a good approximation to the actual values and then can be used in development of the other airplanes

Avaliação de funcionamento das bombas hidráulicas do sistema de tratamento de efluentes da Empresa Parker Hannifin

On the field of the projects of hydraulic systems exists a lot of worries when we talk about the calculate of hydraulic pumps. In this case some facts must be considerate: length of tubes, fluid characteristics, height gauge, temperature, pressure, characteristics of tubes, flow required and others. For that mathematic calculates must be developed with the objective to optimize hydraulic pumps and agree to find an ideal machine (that don't requires more energy than necessary or less energy than it requires; that is the more critical case, cause exists the risk that the fluid pumped do not agree to become in your destiny). The wrong calculate of this machine can super-size its, bringing an excessive energy consumption. Actually it's an important subject because we are in the age of lack of energy what turn it more expensive. So the correct sizing of a hydraulic pump is connected with the fact that you have to uses the enough energy resources avoiding waste. The calculate of ideal pump in the pumping system is studied during years and a lot of specialists in this subject develop equations and theories to calculate its. Some researches study about this subject and all of them become to the same conclusion: to find the ideal pump we have to know the characteristics of fluid (cinematic viscosity), the required flow , overall yield (overall of motor x overall of pump) the high gauge or discharge pressure and the loss of repression. The pressure drop can be calculated with different theories: using Hazen-Williams, Darcy e Weisbach or Chézy (1775 - that starts the researches to calculate the pressure drop). Although the most used theory and what is most near to reality is the Darcy's equation. So, in this job the Darcy's equation were choice to calculate the drop pressure that consider what kind of flow we are studying: laminar or turbulent. The determination of the best pump to be used in the ... ( complete abstract click eletronic access below)

Projeto CHRONOS - desenvolvimento e aplicação de um sistema de freios automotivo

The automobilist Market is more competitive each day, with new products developed by great technological innovations, daily challenging new concepts of Engineering. This monograph aims to explain the development of a brake system project completely, with emphasis on preliminary calculations made from a worksheet in Excel, for a better understanding of the components, which can be improved further in order to achieve the goals of company. It is through the preliminary calculations that we can have a reasonable first system estimate. The whole set is then analyzed for performance, cost and mass by competitors benchmarking. In terms of confidentiality, all data is fictional, but viable. The motivation for this study is approach an extracurricular topic, which essence is designing, base of engineering. The results obtained in software and field tests prove the validity of the study and assist in the continuous improvement of product development

Otimização do braço inferior da suspensão dianteira do veículo Baja utilizando o método dos elementos finitos

Mass reduction coupled with the mechanical performance in service has been the goal of many projects related to the transport area, considering the advantages that mass reduction can bring. However, make a simple material substitution without design a new geometry to corroborate for the best component performance, often makes the replacement unviable. In this study, it was investigated the advantages of replacing the prototype BAJA SAE front suspension lower arm of Equipe Piratas do Vale de BAJA SAE - Universidade Paulista, Campus Guaratinguetá, actually produced with steel, for a new component made of carbon fiber composite. The new geometry has been developed to provide the best possible performance for this component and your easy manufacturing. The study was done using the 3D modeling tools and computer simulations via finite element method. The first stage of this work consisted on calculation of the estimated maximum contact force tire / soil in a prototype landing after jump at one meter high, drop test in the laboratory with the current vehicle, current front suspension lower arm 3D modeling, finite element simulation and analysis of critical regions. After all current component analysis, a new geometry for the part in study was designed and simulated in order to reduce the component mass and provide a technological innovation using composite materials. With this work it was possible to obtain a theoretical component mass reduction of 25,15% maintaining the mechanical strength necessary for the appropriated component performance when incited

Análise dinâmica e estrutural de virabrequim

This paper deals with static analysis and dynamic stress of an ensemble crank and crankshaft, contained within a combustion engine of 4 cylinders. Aimed to illustrate procedures for computer-aided analysis having as goal the optimization of components according to the need for the market demand. Thus, to work in static and dynamic analyzes were summarized the basic theory involved in the calculations and analyzes necessary actuation forces and held a brief introduction about the manufacturing process and forging. Subsequently, it was applied with the use of software in a case the crankshaft, to obtain the performance and structural dynamic thereof. There was a conservative result and critical points in the fillet of the crankshaft bearing, as well as for lubrication hole. It was concluded that there are possibilities for improvements in the manufacturing process and design optimization in order to provide lower criticality and a more robust part

Analise de defeitos em motores através de vibração mecânica: estudo de caso

Revolving machines are among the most used equipment in general industry and therefore expenditures on this equipment class are a significant portion of the total amount spent by the company. If there is an unscheduled stop of some of this equipment, industrial plants can lose huge amounts of money caused by interrupted production and parts delay. Others may increase significantly maintenance costs due to consequences elsewhere not affected before. Even plant and people safety can be in danger if there is an operation interruption without a backup system start. This work is focused on a rotating system case study which is monitored by vibration analysis that shows that is possible to determine when is the most appropriate time for equipment intervention without any reliability loss just by using a simple and cheap system which is not much used because professionals are not aware to its utility. Industrial facilities were evaluated by fail detection and historical analysis in some equipment in order to show feasibility of vibration analysis through a before-during-after process. The plant evaluated is part of a chemical multinational located in Guaratinguetá-SP. At this time, that plant had around 650 critical equipment monthly monitored and no unscheduled shutdown was registered in one year period due to equipment monitoring

Redução de consumo de energia eletrica a partir de reaproveitamento de energia termica com uso de ciclo rankine orgânico

This paper is proposed the usage of an Organic Rankine Cycle (ORC) along with waste heat recovery from an inconstant heat source. This method of waste heat recovery with intermittent heat source is part of a technical viability study. This paper also brings up the usage of thermal energy storage as heat source for the ORC. This paper is based on a heat treatment company study in which a natural gas furnace is explored. Data such as mass flow, temperature and specific waste gas heat from this furnace are used through calculations. Calculations are made also based on furnace cycles. This viability study considers a series of working fluids such as ammonia, benzene, R113 and R134a. Results point out that ORC with out thermal storage and using refrigerant fluid ammonia is the best alternative

Formalismo canônico da mecânica clássica: alicerce da mecânica quântica

We present a succinct review of the canonical formalism of classical mechanics, followed by a brief review of the main representations of quantum mechanics. We emphasize the formal similarities between the corresponding equations. We notice that these similarities contributed to the formulation of quantum mechanics. Of course, the driving force behind the search of any new physics is based on experimental evidence

Análise da estabilidade dimensional e resistência mecânica em bambu Guadua angustifolia pós-processos de tratamentos químicos e térmico

Nowadays, bamboo is being studied because of their strength properties according with their specific mass and speed of growth, which makes it an important alternative as a new resource that will help reduce pressure on forests and helpping them favoring the minimization of uncontrolled deforestation in many regions of Brazil. This study aimed, in general, to analyze physical and mechanical properties of the material with the divulgation of its potential for industrial application. To do so, in this research were determined in relation to the physical properties, moisture content, dimensional stability and the apparent densities and the mechanics and basic, just a tension parallel to grain, in order to observe the interference of various kinds of treatments (chemical, thermal and natural) on the strength and modulus of elasticity in this request. The species used was the Guadua angustifolia, a species native of Brazil. All tests were performed at Universidade Estadual Paulista - Campus Experimental Itapeva in the laboratory of Materials Properties. The methodology used for testing of moisture, density and tension parallel to grain were based on NBR 7190/1997 for the wood, and dimensional stability tests were based on much the same as in COPANT 462/1972 (South American) . The preservative treatments conducted followed the recommendation of each manufacturer. The values obtained in tests of physical properties were satisfactory especially with respect to density and dimensional stability analyzed by the coefficient of anisotropy, showed that, compared to wood, excellent quality for the shrinkage test, obtaining a coefficient of 1.2. With respect to parallel tensile tests to fibre results showed, in most cases, that test specimens with the presence of us have lower values of resistance and modulus of elasticity when compared with those without us. In the treatment of thermal-treatment there was an apparent treatment there was an apparent increase in...

Analise mecânica e microestrutural em estruturas tubulares aeronáuticas soldadas de aço ABNT 4130

Airplane Motor Cradles have a complex geometry, since they require different conbinations between different tubes and TIG welded in several angles. In T-25 aircraft and Universal T-27 Tucano (EMBRAER / FAB), besides having to bear the engine balance, these components maintain fixed the nose landing gear in another extremity. They are considered critical to flight safety, and for this reason, the aviation standards are extremely rigid in their production, imposing a zero index” of defects on the final weld metal quality. These structures may be containing an historical of welding repairs, whose effects on their structural integrity are not computed. In this work we analyzed the standardised AISI 4130 steel and the raw steel of tubes to the Airplane Motor Cradles. First of all, microscopy and microanalysis of the base steel, then we analyzed the effects of the TIG weld. Tensile testing was conducted to measure the difference between the mechanical properties of standardised steel and without this treatment

Avaliação mecânica da colagem estrutural entre compósitos poliméricos e materiais metálicos utilizados em dutos petroquímicos

The development of technology for structural composites has as one of its ends form a set of materials that combine high values of mechanical strength and stiffness and low density. Today, companies like Embraer and PETROBRAS and research institutions like NASA, working with these materials with recognized advantages in terms of weight gain, increased performance and low corrosion. We have developed a systematic study to determine the bond strength between composite carbon fiber / epoxy and fiberglass / epoxy laminate both bonded to a carbon steel which are widely used in the petrochemical industry and repair. For morphological evaluation and bonding between materials of different natures, ultrasound analysis, optical microscopy and stereoscopy were performed. To simulate actual conditions, the composites were subjected to conditioning by using heat shock temperatures from -50 to 80 ° C for 1000 cycles for composite carbon fiber / epoxy composites and 2000 cycles for fiberglass / epoxy . The use of composites studied here proved to be efficient to perform repairs in metallic pipes with application petrochemical, as when exposed to sudden changes of temperature (-50 ° to 80 ° C) cycling at 1000 to 2000 times, its mechanical properties (shear and tensile) practically do not change

Projeto mecânico do sistema de transmissão de um veículo Baja

This study aims to determine the best configuration for the new gearbox of the new Baja´s vehicle from Piratas do Vale team, focusing on the gear train, in order to achieve high performance of it. To this end, first some information about the vehicle is gathered to determine the best pair of gears configuration, then calculations about maximum bending stress, fatigue and surface thereof are performed; ; thereafter static simulations are performed using an a appropriated software. Thus this paper shows a satisfactory design of the addressed, besides providing the Baja SAE team consultation material for future use in the project

Análise de sistemas de máquinas térmicas em plantas de processos químicos

Pressure drop and energy efficiency of compressors in chemical plants are the focus of this study. Its objective is an analysis of possible sources of energy loss through the study of pressure loss in pipes, calculation of thermodynamic efficiency of the compressors. Important issues are raised for this analysis such as the types of compressors, the operating range of each compressor, compression types, as well as a study of accessories such as filters and valves. After studying these issues was carried out calculations of pressure drop step-bystep and with a software WIPCD. Followed by the calculation of efficiency of compressors and monthly energy cost of each compressor in operation. Finally, the study shows some suggestions for immediate improvements, changes and suggestions for possible future purchases of compressors