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Hybrid drivetrain systems are becoming increasingly prevalent in Automotive and Commercial Vehicle applications and have also been introduced for the 2009 Formula1 motorsport season. The F1 development has the clear intent of directing technical development in motorsport to impact the key issue of fuel efficiency in mainstream vehicles. In order to promote all technical developments, the type of system (electrical, mechanical, hydraulic, etc) for the F1 application has not been specified. A significant outcome of this action is renewed interest and development of mechanical hybrid systems comprising a high speed composite flywheel and a full-toroidal traction drive Continuously Variable Transmission (CVT). A flywheel based mechanical hybrid has few system components, low system costs, low weight and dispenses with the energy state changes of electrical systems producing a highly efficient and power dense hybrid system.

Many engineers have been working to reduce brake noise in many ways for a long time. So far, a progress has been made in preventing and predicting brake noise. Nevertheless, there are some discrepancies of brake noise generation propensity between testing for the prototype and the production. As known in general, the reason for this unpredicted brake noise occurrence in production is partly due to the variation of the resonant frequency, material and the other unpredictable or unmanageable variations of the components in a brake system. In this paper, effects of chemical components and casting process of gray iron brake disc on its resonant frequency variation have been studied. Especially this paper is focused on the variation in material aspects and manufacturing parameters during disc casting in usual production condition. And their effects are investigated by the variation of out-of-plane modal resonant frequency.

Permanent magnet AC generators are robust, inexpensive, and efficient compared to wound-field synchronous generators with brushless exciters. Their application in variable-speed applications is made difficult by the variation of the stator voltage with shaft speed. This paper presents the use of stator-side reactive power injection as a means of regulating the stator voltage. Design-oriented analysis of machine performance for this mode of operation identifies an appropriate level of machine saliency that enables excellent terminal voltage regulation over a specified speed and load range, while minimizing stator current requirements. This paper demonstrates that the incorporation of saliency into the permanent magnet generator can significantly reduce the size of the reactive current source that is required to regulate the stator voltage during operation over a wide range of speeds and loads.

During braking, third-body flows and layers govern friction mechanisms, which are fully responsible of the friction coefficient and wear. In the context of development of brake friction pairs, the involved tribological circuit has to be well understood and mastered. This paper concerns a sintered metal matrix composite used for TGV very high speed train. A series of low-energy stop brakings allows a detailed study of the third-body formation at the pad-disc contact. The pin surface is observed after each test. The evolution of the rubbing-area expansion all along the series is explained, and the friction behaviour, typical of the studied friction material, is related to the formation of a well-established third body at the pad-disc interface.

The paper explains the compact fixturing based on magneto-rheological (MR) fluids that have been designed and validated for aeronautic stringers milling. The MR fluid based tooling developed is flexible and reconfigurable as it can be adapted to different profile's lengths and sections and it is able to fix compliant workpieces without reference faces as the MR fluid adapts to the outer shape of each profile. The MR fluid based tooling is suitable to hold non-magnetic materials such as aluminum and also materials that do not admit high clamping forces, such as titanium, because they will appear as deformation after machining due to the memory effect of titanium. The MR fluid based tooling has been tested in a machine environment under real machining conditions and promising results have been obtained.

Extenics is a new cross discipline to study rules and methods of solving contradictory problems in the real world. The basic concepts and theoretical frame of extenics are briefly introduced in this paper. Based on the merit of extenics, the extension evaluation method was applied to evaluate the brake materials according to a five-grade criterion established in this study. Considering the results computed by the original and simplified models, the similar conclusions were made: all four brake samples, marked A - D, were evaluated in the first grade based on the calculated dependence degrees, and sample B was judged as the best performing friction material with the highest dependence degree and the lowest wear rate.

This paper summarizes results from the author's work on friction in dry sliding contacts in the presence of vibration. A number of idealized models of smooth and rough contacts are examined. It is shown that vibration can cause up to a 10% reduction in average friction even with continuous contact. A larger reduction in friction occurs when there is intermittent contact loss. This is found to be true for both elastic and plastic contacts, and for adhesive and plowing mechanisms of friction. The results of this work are compared and validated with measurements from experiments. The results presented are fundamental, but applicable to machine components with contacts including brake systems.

This paper describes the principles of a new method to compensate for tool wear when drilling in complex materials such as Carbon Fibre Reinforced Plastics (CFRP), Carbon Fibre Reinforced Plastics / Titanium (CFRP/Ti) and Carbon Fibre Reinforced Plastics / Alloy (CFRP/AI) stacks. A reliable and repeatable hole quality is essential, especially in automatic drilling applications with robots or gantries. The method combines the unique feature to dynamically adjust the drilling diameter in very small steps in an Orbital drilling End-effector and a new type of software algorithm to predict and compensate for the tool wear in different materials. With this method a large number of holes can be drilled without changing the cutting tool, and a Cpk value of more than 2,5 can be achieved.

Manual drilling and Lockbolt installation in carbon fiber structures is a labor intensive process. To reduce man hour requirements while concurrently improving throughput and process quality levels BROETJE-Automation developed a gantry positioning system with high performance multi-function end effectors for this application. This paper presents a unique solution featuring fully automated drilling and Lockbolt installation (inclusive of automated collar installation) for the vertical tail plane (vertical stabilizer) of large commercial aircraft. A flexible and reconfigurable assembly jig facilitates high access of the end effectors and increases the equipment efficiency. The described system fulfils the demand for affordable yet flexible precision manufacturing with the capacity to handle different aircraft model panels within the work envelope.

Due to the conventional autoclaving of pre-impregnated materials causes high costs in the production of carbon fibre structures, new injection methods have become more and more relevant. The research project “CFK-Tex” focuses on the automated handling and processing of preforms out of dry carbon fibre textiles. Regarding the advantages in quality improvement and process time, an automation of all process steps is getting enforced. The major challenge, in addition to the difficult handling-properties of the materials and high quality demands, is the enormous variety of outline variants caused by small production quantities but many different textile cuts per part. In the first step the requirements of an automated system are exactly analyzed considering the specific material properties as well as process and product based characteristics.

In this paper, the numerical analysis of a three-point bending test of an aluminum foam sandwich structure is performed with the new extended finite element feature supported by Abaqus 6.9. The sandwich beam consists of two aluminum skins and one aluminum foam core. Three different sets of model dimensions are selected for comparison with the reference results (J. Yu, E. Wang, J. Li, Z. Zheng, “Static and low-velocity impact behavior of sandwich beams with closed-cell aluminum-foam core in three-point bending”, International Journal of Impact Engineering, 35, 2008, pp 885-894). Failure modes in this paper can be categorized into three parts: face yield (FY), indentation (IN), and core shear (CS). Face yield occurs on the surface of the core when the thickness of the skin is small. Indentation and core shear occur if the thickness of the skin is relatively large.

Drilling fastener holes in composite is much more difficult than in aluminum or other metallic materials since individual carbon fibers fracture at irregular angles resulting in numerous microscopic voids. These voids can trap excess sealant inhibiting the intimate electrical contact between the fastener and the composite structure. As the cutting tool wears there is an increase of surface chipping and an increase in the amount of uncut fibers or resin. This condition is referred to as machining–induced micro texture. Machining–induced micro texture has been shown to be associated with the presence of arcing between the fastener and the composite structure during lightning strike tests. Lightning protection of composite structure is more complex due to the intrinsic high resistance of carbon fibers and epoxy, the multi-layer construction and the anisotropic nature of the structure.

This paper studies the feasibility and potential benefits of aligning recycled carbon fibres, in the form of short individual filaments, to manufacture fibre reinforced polymer composites. A review of fibre alignment processes is presented to provide insight into the different alignment technologies. The main focus is on wet hydrodynamic processes, which offer a high degree of alignment for discontinuous fibres. The process parameters that govern the alignment efficiency are also reported. The effect of alignment on fibre packing efficiency in the manufacture of composites is included, together with a report of preliminary fibre alignment results obtained from three different alignment processes.

Once qualified, manufacturing processes for safety critical components in aero engines are “frozen”, that is no changes are permitted to be made without a time consuming and costly re-validation. Moreover, the material selection for components in modern aero engines, due to high mechanical and thermal loads in operation, is limited to a small range of super alloys. These difficult to machine titanium and nickel based alloys are on the one hand a significant expense factor themselves, and cause considerable costs due to high tool wear on the other hand. Thus, it is intended to carry out time and resource saving experiments and - ideally - being able to transfer available results to similar processes. Using smart experimental design deploying relationships of physical measures involved, the effort of testing can be reduced. This paper explains the method's mathematical background, how the selection of the regarded parameters is carried out as well as the reduction of system inputs.

In the port injected Spark Ignition (SI) engine, the single greatest part load efficiency reducing factor are energy losses over the throttle valve. The need for this throttle valve arises from the fact that engine power is controlled by the amount of air in the cylinders, since combustion occurs stoichiometrically in this type of engine. In WEDACS (Waste Energy Driven Air Conditioning System), a technology patented by the Eindhoven University of Technology, the throttle valve is replaced by a turbine-generator combination. The turbine is used to control engine power. Throttling losses are recovered by the turbine and converted to electrical energy. Additionally, when air expands in the turbine, its temperature decreases and it can be used to cool air conditioning fluid. As a result, load of the alternator and air conditioning compressor on the engine is decreased or even eliminated, which increases overall engine efficiency.

Unburned hydrocarbon (UHC) and carbon monoxide (CO) emission sources are examined in an optical, light-duty diesel engine operating under low load and engine speed, while employing a highly dilute, partially premixed low-temperature combustion (LTC) strategy. The impact of engine load and charge dilution on the UHC and CO sources is also evaluated. The progression of in-cylinder mixing and combustion processes is studied using ultraviolet planar laser-induced fluorescence (UV PLIF) to measure the spatial distributions of liquid- and vapor-phase hydrocarbon. A separate, deep-UV LIF technique is used to examine the clearance volume spatial distribution and composition of late-cycle UHC and CO. Homogeneous reactor simulations, utilizing detailed chemical kinetics and constrained by the measured cylinder pressure, are used to examine the impact of charge dilution and initial stoichiometry on oxidation behavior.

The present study investigates cold start at very low temperatures, down to −29 deg C. The experiments were conducted in an optical light duty diesel engine using a Swedish class 1 environmental diesel fuel. In-cylinder imaging of the natural luminescence using a high speed video camera was performed to get a better understanding of the combustion at very low temperature conditions. Combustion in cold starting conditions was found to be asymmetrically distributed in the combustion chamber. Combustion was initiated close to the glow plug first and then transported in the swirl direction to the adjacent jets. A full factorial study was performed on low temperature sensitivity for cold start. The effects of cooling down the engine by parts on stability and noise were studied. Furthermore, different injection strategies were investigated in order to overcome the limited fuel evaporation process at very low temperatures.

Researchers at the Powertrain Control Research Laboratory (PCRL) at the University of Wisconsin-Madison have developed a transient test system for single-cylinder engines that accurately replicates the dynamics of a multi-cylinder engine. The overall system can perform very rapid transients in excess of 10,000 rpm/second, and also replicates the rotational dynamics, intake gas dynamics, and heat transfer dynamics of a multi-cylinder engine. Testing results using this system accurately represent what would be found in the multi-cylinder engine counterpart. Therefore, engine developments can be refined to a much greater degree at lower cost, and these changes directly incorporated in the multi-cylinder engine with minimal modification. More importantly, various standardized emission tests such as the cold-start, FTP or ETC, can be run on this single-cylinder engine.

This study describes tests with a fast clocked multispark ignition system intended to improve the stability of inflammation during charge stratification. The advantage of this ignition system is the capability it provides to adjust the number of sparks, the duration of single sparks and the intensity of the primary current. The basic engine test parameters were first set in an optically accessible pressure chamber under conditions approximating an engine. Two strategies were examined to analyze their effect on inflammation in stratified charge mode. On the one hand, the multispark ignition (MSI) system allows implementing an intermittent spark sequence in the spark gap between the spark plug electrodes. On the other hand, precisely timed pulsing of spark energy into the plasma channel during charge motion can generate a very large deflection of the ignition spark.

In this paper, manufacturing hollow cylindrical tank was demonstrated with gas forming of titanium sheets. An innovative gas blow forming method to produce a complex shape of hollow cylindrical tank from titanium multi-sheets by low hydrostatic pressure was presented. Finite element analysis on gas blow forming process has been carried out in order to improve the forming process when manufacturing subscale hollow cylinder structure using Ti-6Al-4V multi-sheets. The simulation focused on the reduction of forming time and obtaining final required shape throughout investigating the deformation mode of sheet according to the forming conditions and die geometry. The result shows that the manufacturing method with gas forming of multi-sheets of titanium alloy has been successful for near net shape forming of subscale hollow cylindrical tank of ramjet engine.