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Metal additive manufacturing has high potential to produce automobile parts, due to its shape flexibility and unique material properties. On the other hand, residual stress which is generated by rapid solidification causes deformation, cracks and failure under building process. To avoid these problems, understanding of internal residual stress distribution is necessary. However, from the view point of measureable area, conventional residual stress measurement methods such as strain gages and X-ray diffractometers, is limited to only the surface layer of the parts. Therefore, neutron which has a high penetration capability was chosen as a probe to measure internal residual stress in this research. By using time of flight neutron diffraction facility VULCAN at Oak Ridge National Laboratory, residual stress for mono-cylinder head, which were made of aluminum alloy, was measured non-distractively. From the result of precise measurement, interior stress distribution was visualized.

Combined Brake System for small motorcycles has been developed. In small motorcycles, some models have a hydraulic disc brake both in the front and rear wheels but many of them have a hydraulic disc front brake and a mechanical drum rear brake. Accordingly, it was necessary to develop a new system to link the hydraulic system with the mechanical system to allow an application of Combined Brake System to these models. In this paper, a CBS having a new configuration is described where a disc brake and a drum brake are linked in a simple lever structure of an input force distributor, and an inhibitor spring at the foot pedal. With this mechanism equipped, the distribution of brake forces is controlled. When a large input force is applied, a large proportion of brake force is applied to the front brake to obtain adequate deceleration. When a mild input force is applied, which is frequently operated, the brake force proportion is large in the rear compared to the front.

The process for setting the marketability targets and achievement methods for automotive interior quietness (as related to air borne noise above 400Hz, considered the high frequency range) was established. With conventional methods it is difficult to disseminate the relationship between the performance of individual parts and the overall vehicle performance. Without new methods, it is difficult to propose detailed specifications for the optimal sound proof packages. In order to make it possible to resolve the individual components performance targets, the interior cavity was divided into a number of sections and the acoustic performance of each section is evaluated separately. This is accomplished by evaluating the acoustical energy level of each separate interior panel with the unit power of the exterior speaker excitation. The applicability of the method was verified by evaluating result against predicted value, using the new method, during actual vehicle operation.

In brake squeal analyses using FE models, minimizing the discrepancies in vibration characteristics between the measurement and the simulation is a key issue for improving its reproducibility. The discrepancies are generally adjusted by the shape parameters and/or material properties applied to the model. However, the discrepancy cannot be easily adjusted, especially, for the vibration characteristic of the disc model of a motorcycle. One of the factors that give a large impact on this discrepancy is a thermal history of the disc. That thermal history includes the one experienced in manufacturing process. In this paper, we examine the effects of residual stress on the natural frequency of motorcycle discs. The residual stress on the disc surface was measured by X-ray stress measurement method. It was followed by an eigenvalue analysis. In this analysis, we developed a unique method in which the residual stress was substituted by thermal stress.

The validity of evaluating FlexPLI peak injury measures has been shown by the correlation of the peak measures between a human FE model and a FlexPLI FE model. However, comparisons of tibia bending moment time histories (BMTHs) between these models show that the FlexPLI model exhibits a higher degree of oscillatory behavior than the human model. The goal of this study was to identify potential improvements to the FlexPLI such that the legform provides more biofidelic tibia BMTHs at the normal standing height. Impact simulations using a human FE model and a FlexPLI FE model were conducted against simplified vehicle models to compare tibia BMTHs. The same series of impact simulations were conducted using the FlexPLI models that incorporated potential measures to identify measures effective for further enhancement of the biofidelity. An additional analysis was also conducted to investigate the key factor for minimizing the oscillation of the tibia BMTH.

This paper describes the development of non-contacting detection type torque sensor that realizes a small lost motion with light weight and low cost. Pedal-equipped electric vehicles are becoming popular in recent years. In those vehicles, torque sensors are usually necessary for measuring the pedaling force to determine the motor torque. We applied an integrated sensing structure and a non-contacting scheme utilizing inverse-magnetostrictive material to minimize the lost motions. As for the sensing material, nickel-iron alloy plating was used to obtain a wide dynamic range. In the tests using the actual structure, the output linearity deterioration occurred because of the strain distribution dispersion produced by the ratchet drive structure. Therefore, the effect of this strain distribution was examined. The inverse-magnetostrictive sensing material of nickel-iron alloy plating has an extremum on its output curve.

Nd₂Fe₁₄B sintered magnets are used in the drive motors of hybrid, electric and other vehicles. A magnet in which rare earth content is reduced by means of a localized diffusion method has been developed in order to reduce the volume of dysprosium. The distribution of the demagnetization fields in a motor is not uniform, so the necessary coercivity distribution for the magnets was quantified using Computer-Aided Engineering (CAE). Then material specifications of the localized dysprosium diffusion satisfied with this coercivity distribution was determined, and optimal manufacturing conditions including the position of dysprosium diffusion were set. The coercivity distribution in every position of the magnet using localized diffusion method was inspected. As a result, the magnet was satisfied with coercivity distribution demanded by CAE.

The effect of equivalence ratio on the particulate size distribution (PSD) in a spark-ignited, direct-injected (SIDI) engine was investigated. A single-cylinder, four-stroke, spark-ignited direct-injection engine fueled with certification gasoline was used for the measurements. The engine was operated with early injection during the intake stroke. Equivalence ratio was swept over the range where stable combustion was achieved. Throughout this range combustion phasing was held constant. Particle size distributions were measured as a function of equivalence ratio. The data show the sensitivity of both engine-out particle number and particle size to global equivalence ratio. As equivalence ratio was increased a larger fraction of particles were due to agglomerates with diameters ≻ 100 nm. For decreasing equivalence ratio smaller particles dominate the distribution. The total particle number and mass increased non-linearly with increasing equivalence ratio.

A new index U* for evaluating load path dispersion is proposed, using a structural load path analysis method based on the concept of U*, which expresses the connection strength between a load point and an arbitrary point within the structure. U* enables the evaluation of the load path dispersion within the structure by statistical means such as histograms and standard deviations. Different loading conditions are applied to a body structure, and the similarity of the U* distributions is evaluated using the direction cosine and U* 2-dimensional correlation diagrams. It is shown as a result that body structures can be macroscopically grasped by using the U* distribution rather than using the stress distribution. In addition, as an example, the U* distribution of torsion loading condition is shown to comprehensively include characteristics of the U* distribution of other loading conditions.

This paper discusses a method of predicting the torque distribution on planet gears originating in manufacturing errors, which is necessary for appropriate strength design of the gears in planetary gear sets. First, an expression of relation between manufacturing errors and the torque on the planet gears in a normal n-planet planetary gear set was derived. As a result, an equation expressing the distribution of torque to the planet gears was obtained. Tests were conducted to verify the validity of the equation in the case of a 4-planet planetary gear set. In order to predict the distribution of torque, it was necessary to estimate the stiffness of the planetary gear set that was the subject of the relational expression. These stiffness values were calculated by numerical analysis using a 3D FEM, into which blueprint values and material property values were input.

Automotive engines are regularly utilized in the material handling market where LPG is often the primary fuel used. When compared to gasoline, the use of gaseous fuels (LPG and CNG) as well as alcohol based fuels, often result in significant increases in valve seat insert (VSI) and valve face wear. This phenomenon is widely recognized and the engine manufacturer is tasked to identify and incorporate appropriate valvetrain material and design features that can meet the ever increasing life expectations of the end-user. Alternate materials are often developed based on laboratory testing – testing that may not represent real world usage. The ultimate goal of the product engineer is to utilize accelerated lab test procedures that can be correlated to field life and field failure mechanisms, and then select appropriate materials/design features that meet the targeted life requirements.

The auto industry has had decades of experience with designing safe vehicles. The introduction of highly integrated features brings new challenges that require innovative adaptations of existing safety methodologies and perhaps even some completely new concepts. In this paper, we describe some of the new challenges that will be faced by all OEMs and suppliers. We also describe a set of generic top-level potential hazards that can be used as a starting point for the Preliminary Hazard Analysis (PHA) of a vehicle software-intensive motion control system. Based on our experience with the safety analysis of a system of this kind, we describe some general categories of hazard causes that are considered for software-intensive systems and can be used systematically in developing the PHA.

Efforts by vehicle manufacturers to reduce road testing have resulted in an increased reliance on the simulation methods for loads measurement and validation, including increased emphasis on methods to characterize and digitally represent test road inputs. Accurate terrain models are especially important in the case of large dynamic road inputs, and for evaluation of vehicle suspension loads and durability. In contrast to direct terrain topology measurement, methods to estimate test road input using only vehicle suspension measurements and a tire dynamic model will be presented. Applications of terrain models for generic simulation and testing will also be discussed.

Over the past decade, the automotive industry has seen a rapid decrease in product development cycle time and an ever increasing need by original equipment manufacturers and their suppliers to differentiate themselves in the marketplace. This differentiation is increasingly accomplished by introducing new technology while continually improving the performance of existing automotive systems. In the area of automotive brake system design, and, in particular, the brake apply subsystem, an increased focus has been placed on the development of electrohydraulic apply systems and brake-by-wire systems to replace traditional pneumatic and hydraulic systems. Nevertheless, the traditional brake apply systems, especially vacuum-based or pneumatic systems, will continue to represent the majority of brake apply system production volume into the foreseeable future, which underscores the need to improve the performance and application of these traditional systems in passenger cars and light-trucks.

An experimental study was carried out on visualization of liquid phase temperature distributions in high-pressure diesel sprays impinging on a heated wall. Naphthalene/TMPD-exciplex fluorescence method and pyrene-excimer fluorescence method were utilized for the thermometry. The sprays were injected into a high-pressure and high-temperature gaseous environment. The nozzle hole diameter was 0.100 mm or 0.139 mm. The results showed that cool pockets were formed at the tip and in the impinging part of the sprays. The spray for the nozzle with 0.100 mm hole was heated up faster near the nozzle than for the nozzle with 0.139 mm hole.

This work discusses the development of SAE procedure J2747, “Hydraulic Pump Airborne Noise Bench Test”. This is a test procedure describing a standard method for measuring radiated sound power levels from hydraulic pumps of the type typically used in automotive power steering systems, though it can be extended for use with other types of pumps. This standard was developed by a committee of industry representatives from OEM's, suppliers and NVH testing firms familiar with NVH measurement requirements for automotive hydraulic pumps. Details of the test standard are discussed. The hardware configuration of the test bench and the configuration of the test article are described. Test conditions, data acquisition and post-processing specifics are also included. Contextual information regarding the reasoning and priorities applied by the development committee is provided to further explain the strengths, limitations and intended usage of the test procedure.

This paper examines the aerodynamic forces on the open hood of a stationary vehicle when another large vehicle, such as an 18-wheel semi-truck, passes by at high speed. The problem of semi-truck passing a parked car with hood open is solved as a transient two-vehicle aerodynamics problem with a Dynamic Moving Mesh (DMM) capability in commercial CFD software package FLUENT. To assess the computational feasibility, a simplified compact car / semi-truck geometry and CFD meshes are used in the first trial example. At 70 mph semi-truck speed, the CFD results indicate a peak aerodynamic force level of 20N to 30N on the hood of the car, and the direction of the net forces and moments on the hood change multiple times during the passing event.

Since 2000, an Aluminum Cosmetic Corrosion task group within the SAE Automotive Corrosion and Protection (ACAP) Committee has existed. The task group has pursued the goal of establishing a standard test method for in-laboratory cosmetic corrosion evaluations of finished aluminum auto body panels. A cooperative program uniting OEM, supplier, and consultants has been created and has been supported in part by USAMP (AMD 309) and the U.S. Department of Energy. Prior to this committee's formation, numerous laboratory corrosion test environments have been used to evaluate the performance of painted aluminum closure panels. However, correlations between these laboratory test results and in-service performance have not been established. Thus, the primary objective of this task group's project was to identify an accelerated laboratory test method that correlates well with in-service performance.

The fuel film thickness resulting from diesel fuel spray impingement was measured in a chamber at conditions representative of early injection timings used for low temperature diesel combustion. The adhered fuel volume and the radial distribution of the film thickness are presented. Fuel was injected normal to the impingement surface at ambient temperatures of 353 K, 426 K and 500 K, with densities of 10 kg/m3 and 25 kg/m3. Two injectors, with nozzle diameters of 100 μm and 120 μm, were investigated. The results show that the fuel film volume was strongly affected by the ambient temperature, but was minimally affected by the ambient density. The peak fuel film thickness and the film radius were found to increase with decreased temperature. The fuel film was found to be circular in shape, with an inner region of nearly constant thickness. The major difference observed with temperature was a decrease in the radial extent of the film.

There is an increasing global realization about the need for fuel efficient vehicles. An inexpensive way to accomplish this is through mass reduction, and one of the most effective ways that this can occur is through substituting current materials with magnesium, the lightest structural metal. This document describes the results of a U.S. Automotive Materials Partnership (USAMP) sponsored study [1] that examines why magnesium use has only grown 10% per year and identifies how to promote more widespread commercial applications beyond the 5-6 kg of component currently in vehicles. The issues and concerns which have limited magnesium use are discussed via a series of research and development themes. These address concerns associated with corrosion, fastening, and minimal metalworking/non-traditional casting processing. The automotive and magnesium supplier industries have only a limited ability to develop implementation-ready magnesium components.