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A fundamental decision to be made in developing a motor vehicle Inspection and Maintenance (I&M) program is whether a “centralized” or “private garage” program will be used. Under the centralized approach, the state or a state contractor operates a network of single purpose “Inspection Centers” to inspect motor vehicles before the completion of the annual registration renewal process. After any repairs necessary to correct vehicles with excessive emissions are made at a facility of the owner's choosing, the vehicle must pass a reinspection at the Inspection Center. Under the private garage (decentralized) approach, both inspections and repairs are conducted by private repair facilities licensed by the state. A comparison of a centralized I&M program and a private garage I&M program currently operating in California indicates that the centralized program is providing over ten times greater emissions reductions.

With the introduction of Organic Acid Technology (OAT) coolants into the automobile and truck markets, it has become necessary to perform elastomer compatibility studies to insure that seal materials will withstand the new fluids. This paper will compare Silicone, EPDM, Hydrogenated Nitrile Rubber, and Fluoroelastomer rubber compound formulations in a conventional coolant and OAT coolants with varying additive packages, Benzoic Acid, 2-ethylhexanoic, 2 mono acids (proprietary), and a Hybrid (European) coolant. Standard bench tests, following ASTM D471 immersion, were used to conduct the evaluations. High temperature, 150°C, a standard specification test temperature, 125°C, and a typical operating vehicle temperature, 110°C was used to measure the effects of high temperature acceleration testing on the elastomers as well as the coolants.

This paper presents a study and comparison of two methods commonly used to treat unwanted vibration in vehicles. Laboratory work was done to measure and compare the effectiveness of common designs for practical tuned mass dampers (TMDs) and particle dampers under a wide range of conditions. The relative strength and weaknesses of the two approaches are compared in their abilities to treat vibration in a system due to resonant modes and forced response. The effectiveness of each method is investigated as a function of the weight of the treatment, amplitude and temperature effects.

Cars in several motor sports series, such as Formula 1, make use of multi-element front wings to provide downforce. These wings also provide onset flows to other surfaces that generate downforce. These elements are highly loaded to maximise their performance and are generally operating close to stall. Rubber debris, often known as marbles, created from the high slip experienced by the soft compound tyres can become lodged in the multiple elements of a front wing. This will lead to a reduction in the effectiveness of the wing over the course of a race. This work will study the effect of such debris, both experimentally and numerically, on an inverted double element wing in ground effect at representative Reynolds numbers. The wing was mounted at two different ride heights above a fixed false-floor in the Loughborough University wind tunnel and the effect of debris blockage modelled by closing sections of the gap between elements with tape.

THE results of an investigation of the vapor-forming characteristics of gasoline are here presented in the form of a correlation whereby vapor-forming characteristics can be estimated from the customary gasoline inspection test data. These results are applicable in considering vapor-lock test data when it is important to know the vapor-forming characteristics of the gasolines employed in the test and, in particular, when it is necessary to apply vapor-lock test results to fuels other than those directly employed in testing.

Light stable polyurethane elastomers, based on aliphatic diisocyanates, have been successfully used in the production of encapsulated automotive glass since 1987. The ultraviolet and weather resistance inherent in these polyurethane polymers have made them the material of choice for many modular windows, both in Europe and the United States. Since the selection of these materials is based largely on their superior field performance, this paper will review a variety of long term durability test data. This data will be of interest to two types of people: 1) engineers designing products which must meet new long term trim warranties 2 manufacturers wishing to eliminate the processing problems and environmental concerns of paint from their production operations.

This paper describes a systematic procedure for designing elastomeric cab and body mounts. Performance characteristics related to load-bearing capability and the control of vibration and shock are discussed; test data on a series of suitable butyl rubber compounds are presented; and an example is worked out showing how the data can be used in reaching a final design. Suggestions concerning design details, specifications, and test methods are included.

Currently used tire models have shown a certain lack of accuracy in some advanced handling applications. This lack of accuracy is believed to be partly due to thermal effects. In reality, the tire rubber temperature is not constant during the normal operating conditions and it's really well known that the tire friction coefficient strongly depends on the temperature level. The temperature generation, propagation and evolution are the result of a dynamic energy equilibrium between phenomena of different natures. Various mechanisms create a non-uniform temperature distribution in various parts of the tire structure: heat is generated in zones with large cyclic deformations due to the energy dissipated from the rubber strains and in the sliding part of the contact patch due to friction. The rubber cools down because the heat energy transferred to the air (internally and externally) and to the asphalt in the stick zone of the contact patch.

An automated drilling and fastening system is under development at the GEMCOR Engineering Corporation for wing manufacture on a new commercial airframe program. It is the first time that cold-working and hole inspection have been integrated into an automated fastener installation system. Numerical control and monitoring of all process parameters have been integrated in the system to achieve the greatest degree of accuracy and repeatability in fastener installation and to provide real-time, in-process statistical quality control. An integral component of the system is a capacitance probe used to measure the diameter and profile of drilled holes. Measurement information obtained with the hole probe is used to monitor the drilling process and predict tooling wear. This paper briefly discusses fastener hole requirements and the effects of hole quality on fatigue life. An overview of the capacitance measurement technique is also presented.

Automobile rubber isolator was subjected to random load cycle for a long time in the service process, and its main rubber material for vibration isolation was prone to fatigue failure. Since the traditional Miner damage theory overlooked the load randomness, it had a prediction error problem. In order to improve the prediction accuracy of rubber fatigue life, the traditional Miner damage theory was modified by random uncertainty theory to predict the rubber fatigue life under random load. Firstly, the rubber dumbbell-shaped test column, which was vulcanized from rubber materials commonly used in vibration isolators, was taken as the research object. The uniaxial fatigue test of rubber under different strain amplitudes and strain mean values was carried out. Then the fatigue characteristic curve of rubber with equivalent strain amplitude as the damage parameter was established.

A general discussion of the problems resulting from the introduction of contaminated jet turbine fuel into integral fuel tanks and a five-point program designed to eliminate the contamination problem are presented. Some areas covered are: inspection of fuel sources for contamination to prevent contaminants from entering the aircraft fuel system; decontamination of fuel sources; inspection and decontamination of the aircraft fuel system; use of additives for the control of microorganisms; materials and methods, including a simple system for introducing the additives. The good and bad points of all fuel tank sealing and finishing systems presently in use are discussed, and a new finish system completely resistant to degradation by microorganisms is introduced. Simple means of controlling fuel quality entering the aircraft from uncontrolled sources are outlined.

Design for Six Sigma (DFSS) is a product improvement process based on statistical problem solving capabilities which is typically followed IDDOV approach - Identify, Define, Develop, Optimize, and Verify the design. Flexible inspection system (FIS) is defined as one where the inspection routines are not fixed but are determined just prior to performing the inspection [1]. In FIS the inspection stations have the capacity of performing different inspection routines according to a global inspection strategy. In this paper, the IDDOV steps, as well as some DFSS variation analysis techniques, are applied with the FIS to provide an analytical framework for an optimized strategy of real time inspection allocations.

In the use of radial lip-type oil seals to seal against a rotating shaft, the surface characteristics of the shaft are important to the sealing and to the resultant seal/shaft friction. A plunge ground shaft surface with no lead has long been the recommended mating surface for a radial lip-type oil seal. Recently, however, a peened surface was studied which will reduce frictional torques a maximum of 50%, 60%, and 70% below that of one utilizing a plunge ground shaft surface for silicone, nitrile and polyacrylate seal materials, respectively. Seal performance from a leakage standpoint for standard sharp lip seals exceeds that of the plunge ground surface. However, the preliminary results indicate that the surface is not suitable with hydrodynamic shaft seals. Some insight into elastomeric friction was obtained from the tests.

Each new model change usually brings improvements over earlier models. From the point of view of increasing window area and designing more pleasing appointments, there have been significant advances. With regard to engine reliability and time between overhauls, significant advances have also been made. Solutions to some of the other problems, however, have made little gains. Examples are pilot sitting position and ease of seeing outside the cockpit area; noise level for effective verbal communications between instructor and student; and shoulder space for instructor and student in trainers. An area where major strides are yet to be made is in panel, cockpit, instrument, and control layout and function. A continuing concern expressed by pilots is the transition time from one aircraft to another or the problems of regularly operating in two or more aircraft. This suggests that there is a need to provide more commonality between airplane layouts.

As the complexity of current automobiles increases, new and innovative diagnostic methods for car maintenance and diagnostic inspection are greatly needed. This paper introduces a new diagnostic approach, which learns from previous repair cases with the help of neural networks in order to assist future diagnostic inspections. Practical experiments have shown that this approach is able to provide promising results even with the data that is already available today.

A new concept in pneumatic energy absorbing bumper systems for motor vehicles has been developed, the dynamic testing of which demonstrates considerable promise in dissipating large blocks of energy in an accident situation. Having a flexible front section molded from a castable elastomer, the pressurized system is equipped with relief valves that open at a predetermined pressure during collision, thus dissipating energy.

Tire is an integral part of any vehicle which provides contact between the vehicle and the surface on which it moves. Forces and moments generated at the tire-road interaction imparts stability and control of motion to the vehicle. These forces and moments are functions of many variables such as slip, slip angle, contact pressure, inflation pressure, coefficient of friction, temperature, etc. This paper deals with the effect of temperature on the lateral force, the longitudinal force and the self-aligning moment. The analysis is done at different tire surface temperatures such as 20°C, 40°C, and 60°C. Since the experimental set up with the mounted tire is complex and expensive, we use a hybrid approach in which we take the results from the experiments done by the researchers on a sample piece of tire rubber at various temperatures.

This paper describes a hybrid transmission consisting of a Salsbury style rubber belt continuously variable transmission (CVT) and a two-speed manual transmission. Rubber belt CVT transmissions are used extensively in the Mini Baja competitions. Although widely used, rubber belt CVTs have a limited torque ratio range, and teams must reach a balance between top speed and pulling or hill climbing capability. The hybrid transmission described in this paper provides a wider range of torque ratios by combining a CVT with a two-speed manual transmission. Included is a description of the major components, a derivation of the equations used to model the primary pulley in a simulation used to select the desired gear ratios, and a summary of performance characteristics obtained from testing.

This paper presents our efforts to formalize the knowledge domain of nondestructive quality control of automotive composite components with organic (resin) matrices and to develop a prototype knowledge-based system, called NICC for Nondestructive Inspection of Composite Components, to help in the quality assurance of individual components. Geometric and bonding characteristics of parts and assemblies are taken into account, as opposed to the better understood evaluation of test specimens. The reasoning process was divided in two stages: in the first stage all flaws that might be present in the given part are characterized; in the second stage appropriate nondestructive testing procedures are specified to detect each of the possible flaws. The use of nondestructive techniques in the inspection of composites is fairly recent and hence, the knowledge required to develop an expert system is still very scattered and not fully covered in the literature.

The Standard Oil Development Company has developed a new test for evaluating the sludge handling ability of lubricants. Oil Sludging Test measures the sludge handling ability of lubricants in terms of the time required to reach 50% oil screen plugging in cyclic laboratory engine operation. The manner in which sludge builds up in this test is similar to the way it builds up in field engines. Results correlate very well with those obtained in low temperature, stop-and-go field service. The test conditions were chosen after studying the conditions found to be conducive to sludge formation in the field. A six cylinder, overhead valve engine is modified by enlarging the piston ring gaps to increase blow-by. It is then run in 4 hour cycles. Each cycle includes 1-1/2 hours of idle with 115°F. oil temperature and 2 hours of loaded operation with 180°F. oil temperature. This is followed by a 1/2 hour shutdown under cold conditions.