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Traditional suspension tuning for ride comfort takes use of a series of physical prototype evaluations by skilled drivers, who analyze the vehicle performance in subjective terms. In this approach, the suspension components (springs, shock absorbers, bumpers, etc) are usually optimized one at a time, regardless of the consequences of the interactions among them in the global suspension behavior – this not uncommonly leads to sub optimized suspension configurations. Another problem with this approach is the fact that it is completely dependent upon physical component prototypes, whose costs and construction lead times can not be afforded in the current tight development cycles. This paper presents an objective approach that has been successfully applied at GMB, based on simulation tools, whose target is to define optimized components for the suspension without the need of physical prototypes.

The imprecision of altimeter system in higher altitudes, utilized by aircrafts in past decades, although adequate for lower levels, imposed that minimum separation between flights levels FL290 (29000 feet) and above had to be 2000 feet. This higher separation limits aircraft capacity on these levels where jets are more efficient and, therefore, is undesirable to airline companies, taking account, principally, the fuel economy. The advance of electronic technology in altimetry system has permitted to obtain a better precision of altitude measurements and, thus, reducing the minimum vertical separation between these levels to 1000 feet became safer, showed by figure 1. This process is called RVSM (reduced vertical separation minimum) and presents some characteristics such as introduction of 6 news flight levels. This process defines special requirements related to airspace and it was implemented in North America and Europe in last years.

In order to increase the stiffness of cylinder head plastic valve cover system (PVCS), short glass fibers and minerals are added during the injection molding of the plastic valve cover. The fibers orient themselves according to the local characteristics of the flow and the geometry of the part. The presence of the fibers results in a component with highly anisotropic thermo-mechanical properties. Traditional finite element analysis methods do not account for this, very important, phenomenon. The present manuscript describes work conducted at Dana Corp. aimed at incorporating short fiber anisotropy into the design of cylinder head valve covers.

This work presents the development of a rotor test rig specially devised to analyze different rotor-bearing systems running at several operating conditions. The test rig allows testing single and two disk rotors of different lengths supported on oil lubricated journal bearings. Experimental setup includes a rotational speed controller, which is achieved by a frequency inverter and a conventional electrical motor, accelerometers mounted on the bearing caps and a frequency analyzer. Frequency spectra of different rotor configurations are taken through many rotating tests. Cascade plots of some rotor configurations during run-up and coast-down tests show important dynamic characteristics of rotor-bearing systems in function of the rotating speed. A discussion about the analysis and monitoring procedures on the early design stages of rotor-bearing systems is also presented in this work.

Several heater cores failed due to erosion by cavitation. After analysis, most of failures were explained by the presence of impurities in the heater core. It was then decided with the customer to use CFD simulation in order to prove that the cavitation was not caused by design concept of the tank. In this paper, we present the results of heater core simulations done in 2D and in 3D with Fluent. The objective is to simulate the pressure and velocity distribution within the heater core and to verify if the zones of low pressure are below the saturation vapour pressure of the fluid causing cavitation. In these areas, the deterioration of the tubes might occur due to erosion by cavitation.

This paper consists in a definition and analysis of rear suspension geometry to an off-road vehicle. The suspension selection was accomplished through the study of its geometric characteristics to design its dimensions and position of installation in the vehicle according to the expected behavior. The current suspension of the vehicle, on the front and rear axles, was analysed for understanding its dynamic behavior. The vehicle submitted to analysis was a “Mini-Baja”, off-road prototype, which is used to run nationals competitions between engineering colleges. Its top speed is 50 km/h and its turn diameter is 8.2 m.

This paper intends to show the technological progress in target wheel for rotational monitoring according to newest requests of internal combustion engines (ICE). This job has been made in accordance to automaker specifications, as a consequence it is focused on current injection management system by engine control unit (ECU). The project has been developed based on market prospection, benchmarking, material/process development, validation procedure, etc, These subjects helped to reach such a technological improvement that it raised engine injection management, boosted ECU signal accuracy, and minimized engine emissions and consumption (state-of-the-art solution).

The energetic efficiency of automotive vehicles can be increased through the use of regenerative brake system. This paper introduces a mathematical model of an ABS (anti-lock braking system) pneumatic regenerative brake. In regenerative brakes the energetic efficiency of automotive vehicles is increased through the conservation of part of the kinetic energy of the vehicle. In this work we propose a pneumatic system where the energy is stored in an air compressed state. In this system, the brake is equipped with the anti-lock braking system (ABS) and the regenerative brake acts in a parallel way with the traditional brake. In this work, it is shown that, due to the fact that ABS system takes advantage of the maximum adherence between the tire and the ground, the use of an anti-lock braking system (ABS) allows a greater energy saving when compared to passive braking system. The simulations were performed for wet and dry asphalt.

This work presents the development of a braking system model to be applied in the evaluation of anti-lock braking system (ABS) control logics. The anti-lock braking system model was attached to a vehicle model to simulate possible braking conditions. The results show that the vehicle stopping distance with a standard anti-lock braking system is reduced when compared to the passive braking case and that the wheel slip is much closed to the desired wheel slip, confirming the appropriate working of the proposed anti-lock braking system control logic. The simulations were performed for snow, wet and dry asphalt. The parameters used to verify the performance advantage obtained with ABS braking in relation to passive braking were the stopping distance, the anti-lock braking system index of performance (ABSIP) and the vehicle side slip angle for the tests with steering input. In these cases, the results also show an efficiency improvement with the proposed anti-lock braking system.

This paper presents a software developed to apply the Hertz contact formulation to bearings with rolling elements, estimating the occurrence of surface fatigue failure in this kind of parts. Considering the wide range of designs in the automotive industry using this kind of bearings, a dedicated software, using a simple language, becomes a useful tool to reduce the design time, predicting in a satisfactory manner the failure of the bearing. The software developed shows a high level of accuracy, when compared to data provided by rolling bearing manufacturers.

The optimization of internal components in a shock absorber is today a task that demands a significant experimental support and a great number of prototypes and tests. Aiming to reduce the development time, a CFD (Computational Fluid Dynamics) model can be used in order to predict and study the flow through several valves and internal components in a shock absorber. The present work approaches the first development stage of a complete CFD shock absorber model. This stage consists of the flow simulation through an existing clearance between the shock absorber piston and the tube, studying the effects and its relations with the resultant forces. The results of the simulations have been compared with analytical calculations and experimental tests in order to validate the model.

Vibration and noise signals coming of performing measurements in rotating systems - like reciprocating engines, transmissions, compressors, and pumps, for example - operating in non-stationary condition present some harmonic components that are rotational speed dependent, which are commonly know as orders. It is well known that if one intends to isolate one or some components of these signals, it is not recommended to use the traditional Fast Fourier Transform - if the analysis is in the frequency domain - or a fixed frequency band filter - to study it in the time domain. In these cases, it is important the use algorithms capable of treating those signals properly. This paper deals with the utilization of the Vold-Kalman filter to extract or eliminate a specific order component. This type of filter is able to track a time variant component using a reference signal - usually the angular displacement or velocity of the shaft.

The present paper will show a methodology to develop shock absorbers using finite element method. It will presented which components are involved in the model from shock absorber considered by finite element method. It is presented also the procedure to create the components as well as the types of elements, formulation, parameters of mesh quality, warpage factor as well as the others parameters necessary that, must to be use for a consistent numerical results when compared with experimental data. The boundary conditions used and the procedures to apply forces will shown too. CAS Brazil use Hypermesh for pre-postprocessor and ABAQUS for solver linear and nonlinear problems. Is presented an example of the methodology as well as the validation with experimental data.

The Complexity Theory (or Chaos Theory) has already brought a lot of contributions to many areas of the human knowledge, such as Physics, Biology, and Chemistry. However, only recently it has been applied to social systems and to management. Even with all the theoretical bases that the management techniques have today, and with the supposed control managers have over the business indicators, we often face contradictions between our expectations and the organization’s expectations towards business reality. This work has the intention to present and reveal how the recent progresses on the comprehension of the system dynamics based on the Complexity Theory can contribute to the construction of a new rational model of management that fits an environment of constant changes in which the organizations are in.

This paper presents a two-parameter Weibull distribution shape and scale parameters calculation method, using sample average and standard deviation. The proposed procedure requires fewer resources for field execution than least squares and maximum likelihood methods, since these methods usually require the use of computers and specific software. Weibull probability paper is easier to apply in the field, but it becomes time-consuming for larger samples.

Due to changes in competitiveness attributes, consequence direct of technology development, new markets and customer profile, it has been required continuous improvement in the tools and methodologies of Quality and Productivity management to maintain the organization's health. These are new requirements for project managers that facing the challengers in the 21st Century in Automotive Industry. The Lean Manufacturing was a great innovation in this area because improve the organizations profitability, which is necessary for they survive in the competitive new scenarios that we are currently confronting. Allied with these new constraint conditions, the Six Sigma Methodology helps the organizations to improve the Value Add within the business process and to avoid wastes, which are responsible for lack of focus, increase of process costs, decrease of customer satisfaction and consequently lack of competitiveness.

A polycarbonate (PC) and poly (butylene terephthalate) (PBT) blend is extensively used for molded automobile parts. PC is tough and stable to 300 °C and PBT has relatively good solvent resistance. An alloy formed with those two polymers produces a material with good chemical resistance as well as good heat and impact resistance. In this work, a PC/PBT blend with and without pigment was aged by natural and accelerated methods. Tensile and impact properties were evaluated before and after aging, and after recycling. The rupture elongation of the recycled material was very good, showing the recycling potential of this material. The impact strength of the recycled material showed property decay.

In the early 1990s, Brazilian automotive industries have testified a new scenario with a competitiveness increased due to the establishment of foreign companies, which forced them to follow new strategies to maintain its competitiveness in the market. Innovation and quality become priority, as well as new technologies and product cost optimization. More specifically, the focus on current automotive products cost reduction is nowadays one of the most important strategies to provide significant increase in profits and market share of companies. The purpose of this paper is to introduce case studies and the technical and economical benefits of product optimization process applied in current automotive components, where the requirements of quality maintenance, performance and cost reductions are emphasized.

This paper came from the latent needs of the Brazilian Market for products more robust and at the same time cheaper. With these needs in mind the product development team of General Motors do Brasil have developed together with Altair Engineering do Brasil a design methodology based on the topologic optimization technology. The objective of this paper was defined in a meeting of the technical teams of the two companies: Develop the application of the topologic optimization technology on design of structural components using actual GMB models. This methodology is described on this paper with some practical examples where it was applied. One the important news here presented it was considering the casting constrains that leave to an optimal design that can be produced. The results here presented were obtained using optimization and compared with the traditional approach here defined as try-error.

Vehicle audio system performance is an important attribute for final costumers. In this sense, its evaluation is an important aspect for selecting the design and validation process for automobile manufacturers. Usually the vehicle audio system performance is evaluated only by subjective judgment. However the design requirements demands objective measurements to set targets establish benchmarking and apply refinements to the design. Thus, in order to evaluate and improve sound system performance, it has been established a subjective evaluation process on reproducing and analyzing customer perception in a more reliable way. To support this information, objective evaluations have been used based on total harmonic distortion (THD), normalized frequency response (NFR) methods and spectrogram, which have been shown as straight and fast objective tools. Reinforcing the objective evaluations, qualitative time-frequency spectrogram has been used.