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Recent experimental work involving surfaces is described, and it is shown that by measuring the distributions of asperities, it is possible to evaluate the nature and size of contact for various surface loads. The removal of adsorbed gas layers from the surfaces of crystals is shown to affect the friction markedly, while the “ploughing” term in the frictional cooefficient emerges as the important factor in explaining the anisotopy of friction found on some crystalline solids. The effect of microdefects on the strength of glasses and their removal by etching is described. The behavior of glasses is compared with that of hard polymers such as lucite. Finally, the property a surface has as a “free boundary” in stress wave propagation is considered, with particular reference to the fracture behavior of brittle solids in plate form.

The University of Washington EcoCAR2 team (UWEC2) is currently in the process of building a Plug-in Hybrid Electric Vehicle (PHEV) for the EcoCAR2 Challenge. This competition challenges 15 universities across North America to reduce the environmental impact of a 2013 Chevrolet Malibu without compromising consumer acceptability. In order to be competitive in EcoCAR2, grid electricity is relied on heavily and the use of the Utility Factor method presented in SAE J2841 - Utility Factor Definitions must be used to compare emissions and consumption results with traditional vehicle results. Powertrain simulation in Autonomie was performed to explore many different hybrid architectures. The simulation results were normalized using the Utility Factor method to reach final architecture and component decisions.

Traditional electrode materials for lithium-ion storage cells are typically crystalline layered structures such as metal oxides, and graphitic carbons. These materials power billions of portable electronic devices in today's society. However, large-scale, high-capacity storage devices capable of powering hybrid electric vehicles (HEV″s) or their plug-in versions (PHEV's) have much more demanding requirements with respect to safety, cost, and the power they must deliver. Recently, nanostructured solid state materials, which are comprised of two more compositional or structural phases, have been found to show exciting possibilities to meet these criteria.

The dry stripping process utilizing plastic media has proven to be a viable alternative to chemical stripping or hand sanding operations. This process has been subjected to extensive testing over the last two years by a number of commercial and military agencies and is now being successfully employed on large numbers of commercial, military and private aircraft, aircraft subcomponents and ground support equipment. In most cases, the end user can expect a significant increase in production rates and sizeable reduction in paint stripping cost, in addition to the elimination of health and disposal problems associated with chemical stripping operations. The successful use of the process requires an exact match up of the requirements dictated by the workpiece with the controllable elements of the process. This precise control of process variables must be predictable and consistent in production.

An improvement in a vehicle's front of dash barrier assembly's acoustical performance has in the past been addressed by both adding individual absorbers and increasing the overall weight of the dash sound barrier assembly. Depending upon the target market of the vehicle, adding mass may not be an option for improved acoustical performance. Understanding the value of an increase in vehicle mass and / or cost for a specific level of improved acoustical performance continues to plague both Original Equipment Manufacturer (OEM) Engineers and Purchasing representatives. This paper examines the importance of properly sealing the front of dash pass-through areas and offers recommendations which can improve the overall vehicle acoustical performance without the addition of cost and mass to the vehicle.

Vehicle vibration and shock can impair the health and performance of both driver and passenger. The results of the more recent investigations into these effects are reviewed. The frequencies and amplitudes of vehicle vibrations are related to the whole body response of man to these vibrations and the role of the vehicle seat as a protective device is discussed.

Automotive thermal reactors have obtained high conversion efficiencies on engines with very rich carburetion, but fuel economy and reactor durability have suffered. Improved mixing of exhaust gas and secondary air in the engine exhaust port was examined as a means of improving reactor efficiency at less rich engine air-fuel ratios. Three air-injection systems which span a broad range of mixing capabilities were examined. Mixing characteristics were deduced from anemometry measurements of instantaneous secondary airflow, and emission performance of each system was generalized by a test program employing four steady-state conditions. High-pressure, timed air injection provides the best mixing and the best reactor performance. Sparger (radial discharge) air injection tubes provide fair mixing and better performance than conventional open-ended air injection tubes, which exhibit poor mixing characteristics.

This paper discusses the causes of abrasive wear in mobile vehicle hydraulic systems and presents laboratory and field data that show why ultrafine filtration is required to control degradation of fluid system components caused by abrasive wear. Among the advantages of ultrafine filtration are the vehicle manufacturer's reduced warranty and flushing costs, and user benefits of longer fluid and component life, less downtime, fewer spares, and less maintenance man-hours.

In the not very distant past, interiors were put into the aircraft after everything else had been accommodated. As a corollary, interior designers were called in, if they were called in at all, after everyone else had done his work. However, the general aviation industry under the stimulation of competition and the example set by other consumer oriented industries, notably the automotive industry, has come to recognize that the passenger is paramount and, since his needs and desires must form the basis of marketing policy, the physical expression of these needs and desires must be the platform on which the airframe design is based. This paper examines the function and organization of an industrial design department; styling as a marketing tool; and the use of materials in aircraft interiors.

Lean production has greatly influenced the way manufacturing systems should be designed. One important aspect of lean production is takt time. Takt time relates customer demand to available production time and is used to pace the production. This paper applies the manufacturing system design and deployment framework to describe the impact of takt time on both the design and the operation of a manufacturing system. The goal of this paper is to illustrate the relevant relationships of takt time to overall system design.

Approximately 50% of the industrial processes are related to the measurement and control of temperature. The automotive industry often uses thermocouples, transducers that work according to thermoelectric principles. For higher measurement reliability it is necessary to calibrate these transducers, preferably at low cost. The thermal laboratory at DCBR is developing calibration procedures and the evaluation of associated uncertainties. The object of this article is to present the thermocouple calibration process among other transducers and specially the importance of their vehicle application.

This paper discusses the importance of having an adequate model for the dynamic response characteristics of tire lateral force to steering inputs. Computer simulation and comparison with experimental results are used to show the importance of including appropriate tire dynamics in simulation tire models to produce accurate predictions of vehicle dynamics. Improvements made to the tire dynamics model of an existing vehicle stability and control simulation, the Vehicle Dynamics Analysis, Non-Linear (VDANL) simulation, are presented. Specifically, the improvements include changing the simulation's tire dynamics from first-order system tire side force lag dynamics to second-order system tire slip angle dynamics. A second-order system representation is necessary to model underdamped characteristics of tires at high speeds. Lagging slip angle (an input to the tire model) causes all slip angle dependent tire force and moment outputs to be lagged.

This paper investigates the effects of the variations of turbulence characteristics and initial flame kernel center position on the cyclic combustion variations by means of quasi-dimensional turbulent entrainment combustion model. The turbulence intensity and turbulence integral length scale at spark ignition time in the model are determined by maximizing the agreement between the predicted and measured results such as pressure diagrams, mass fraction burned etc. With different values of the turbulence intensity and turbulence integral length scale at spark ignition time, the calculation of the cyclic combustion variations for the engine is carried out. In addition, the prediction of the effect of different flame kernel center positions on the cyclic combustion variations is also studied. Finally, some conclusions are drawn out about the importance of turbulence and initial flame kernel center position on the cyclic combustion variations for spark-ignition engine.

The early detection of incipient failure in a mechanical system is of great practical importance as it permits scheduled inspections without costly shutdowns and indicates the urgency and locations for repair before a system incurs catastrophic failure. However, in this work a new technique for processing vibration data to quantify the level of damage, cracks only, in a gear system. The technique consists of a nonlinear numerical optimization. The optimization uses a dynamic model of the gear mesh used in vehicle gearbox and forms an estimate of both time-varying and frequency-varying mesh stiffness that best corresponds to the given set of vibration data. The procedure developed in this study can be applied as a part of either an onboard machine health monitoring system or a health diagnostic system used in the regular maintenance.

This study examines the influence of padding in thorax side impact response under free-flight impact and velocity pulse impact. It was found that padding reduces rib and spine accelerations in both types of impact. However, in free-flight impact, padding reduces chest V and VC response without significant deformation change, while in velocity pulse impact, padding reduces chest V but substantially increases VC and deformation. It appears that free-flight impact lacks spacing effect and the correct velocity profile to simulate the door/occupant impact in car-to-car side collision. On the other hand, velocity pulse impact has the essential characteristics of the door/occupant impact in car-to-car side collision and is a more suitable method for subsystem test.

Mechanical drawing plays an important role in managing, designing and implementing engineering projects, especially in the field of the automotive industry. The need for accuracy in element design and manufacturing is greater now than ever before in engineering industries. In order to increase accuracy, the part design and function must be clearly communicated between the design engineer and the manufacturing technicians, especially in automotive industry and feeder industries projects. Geometric Dimensions and Tolerances (GD&T) system of elements determines the quality, importance and price of the designed product. The standard used in the United States to define GD&T methodology is ASME Y14.5-2009 while the standard used in Europe is ISO 1101-2017. This article discussed the importance of using GD&T system including the types of geometrical features, limitations and accuracy, datum references frame and feature control frame to handle these symbols seamlessly.

One of the reasons for the large number of road accidents on highways in Ukraine [1] is the instability of the braking properties due to the unstable characteristics of the brake mechanisms’ friction pairs. The manufacturer produces new automobiles with installed brake pairs (brake pads and their counter bodies), which have passed long-term tests for the stability of the friction coefficient and braking forces distribution of between the axles. This ensures the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. During operation, instead of worn-out brake pads, brake discs and drums, drivers can purchase new ones, manufactured as spare parts. However, in the well-known literature there are no methods that allow to check the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance.

In this paper is presented an experimental research in which the grinding of seating surfaces of inlet engine valves was improved by the adoption of the most effective cutting fluid type, matching the new requirements of cutting fluid application. Four different types of cutting fluids (straight oil and three different types of soluble oils) were analyzed. As qualitative and quantitative evaluation parameters of the performance of the cutting fluids, the roughness, the grinding wheel wear, the cutting force and the workpiece residual stress were determined. As a conclusion, the straight oil was the cutting fluid that presented the best results in all of the parameters analyzed.