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Past experiences showed that the retainer life varied across different types of pressure regulators - even when the retainer designs and materials remained the same. The objective of this work was to identify the root causes behind this phenomenon and to improve the retainer life. Both analytical and experimental approaches were employed. For the analytic approach, a CAE tool (the SABER code) was used to simulate the system dynamics of the pressure regulator components (as main spring, valve body, valve ball, retainer, and valve spring) under repetitive pressure surges caused by fuel injection. The predicted relative motions were used to characterize impacts between the valve ball and the retainer, and then to estimate the retainer life through a simplified fatigue model. Effects of nine parameters on pressure regulator's dynamic performance were studied.

This paper presents a strategy to improve fuel atomization during warm-up. Heating the fuel inside the fuel-rail plans improvement on fuel atomization. In this experiment, the heated fuel-rail system is constructed to investigate the reduction effects on the size of the fuel droplet by fuel heating. The fuel atomization is examined by measuring Sauter Mean Diameter (SMD) of the fuel droplets from the three different types (two-hole, pintle, and six-hole) of injectors based upon the returnless heated fuel-rail system. The results show that the six-hole type injector with the heated fuel provides the best fuel atomization results in terms of SMD among three different types of injectors.

The majority of hydrocarbon (HC) emissions in the FTP cycles are generated during cold starts when the catalyst is cold, and a large percentage of the injected fuel does not vaporize well. D Dduring this portion of the test, a wall film builds on the intake ports, fuel drips into the cylinder, and manifold pressure changes cause excursions in the air/fuel ratio (AFR). This paper presents the concept of heating fuel inside an injector to enhance vaporization in the intake manifold. Different injector parameters, such as heater temperature and injector tip geometry, were analyzed for different flow rates. The heat transfer inside the injector was investigated experimentally and numerically, using computational fluid dynamics (CFD) modeling. The Sauter Mean Diameter (SMD) of the fuel spray was measured and evaluated under different vacuum conditions using a Phase Doppler Particle Analyzer (PDPA).

In this paper fundamental analytical results for automobile lateral stability are developed. Specifically, the linear two degree-of-freedom, fixed steering control, front wheel steer and four wheel steer automobiles with a time lagged lateral tire force model is employed in the analysis. The stability conditions are derived using Routh Hurwitz criterion and Lyapunov’s method. The results are mainly algebraic in nature and examples are given demonstrating potential problems of front wheel and four wheel steering vehicles due to the time lag in the tire’s lateral force.

This paper introduces and discusses a new 2D physical model which has been developed and validated in order to study and optimize the handling behavior of the tire. It can be divided into two parts, the structural model and the contact area model. The parameters, that are function of the vertical load, are identified or calculated by comparison with the results provided by 3D finite element models. The input data for the identification procedure consist of a set of frequency responses performed on the finite element model. A second set of simulations on the 3D model of the tread pattern gives the characteristics of the contact model. Once built the 2D model it is easy to carry out both steady state and transient analysis. The steady state analysis returns the cornering carpet, in terms of lateral force and self-aligning moment as function of the cornering angle. The transient analysis allows the evaluation of the relaxation length and dynamic characteristics.

This paper is looking both at testing and simulation of tyres under stationary and dynamic operation conditions. The new dynamic ika tyre test rig will be introduced and its particular advantages in tyre testing are explained. First results are shown and the reproduction of measured tyre properties with an efficient tyre model is demonstrated.

A new approach for improving estimates of the kinematic response of ATDs (anthropomorphic test devices) to vehicle crash events has been developed. This approach employs the Kalman Filter; a state model based estimation approach that has been widely applied to system dynamics problems ranging from navigation to missile guidance. The Kalman Filter approach combines measurements of crash event phenomena (acceleration and displacement), kinematic models of ATD behavior and statistics of sensor noise to create precise estimates of ATD motion during a crash. This paper presents an implementation of a state model and Kalman Filter for a sensor data collected from the chest of an ATD during an out-of-position airbag deployment test. Favorable comparisons are made between the Kalman Filter model approach and traditional methods involving numerical integration and differentiation.

This paper discusses the use of a new double filament light source in reflector optic designs of headlamps for ECE and US VOA applications. An explanation of the development of the bulb is offered and the unique features intrinsic are examined. Methodology for using this source to produce low glare and a sharp gradient cut-off in headlamps is discussed. Factors, which must be taken into consideration with this new bulb, are presented for review. Experimental results of the bulb analysis and headlamp photometric performance are included.

Numerous studies have documented that lower extremity injury is second only to the head and face in automotive accidents. Such injuries are common because the lower extremity is typically the first point of contact between the occupant and the car interior. Of all lower extremity injuries, the knee is the most common site of trauma. This typically results from high speed contact with the instrument panel which can produce fracture and subfracture (contusions, lacerations, abrasions) level injuries. Current Federal safety guidelines use a bone fracture criterion which is based solely on a peak load. The criterion states that loads exceeding 10 kN will likely result in gross bone fracture. However, cadaver experiments have shown that increased contact area (via padding) over the knee can significantly increase the amount of load that can be tolerated before fracture or subfracture injury.

The Eurosid-1 dummy was subjected to a series of lateral and oblique pendulum impacts to study the anomalous “flat-top” thorax deflection versus time-histories observed in full-scale vehicle tests. The standard Eurosid-1, as well as two different modified versions of the dummy, were impacted at 6 different angles from -15 to +20 degrees (0 degrees is pure lateral) in the horizontal plane. The flat-top deflections were observed in the tests with the standard Eurosid-1, while one of the modified versions reduced the flat-top considerably. Full scale vehicle tests with the standard and modified Eurosid-1 suggest similar reductions. A second series of tests was conducted on the modified Eurosid-1 to investigate the effect of door surface friction on the shoulder rotation and the chest deflection. The data suggested that increasing the friction on the door surface impeded shoulder rotation and ultimately reduced the chest deflection in the Eurosid-1.

The main objective of this study is to determine the damage tolerance and describe the damage mechanisms of the extended human knee when it is exposed to lateral impact loads in car-pedestrian accidents, particularly those that occur at a low velocity (20 km/h), and compare the results with those obtained at a high velocity (40 km/h). In-vitro experiments with human subjects were conducted where only the purest possible shearing deformation or the purest possible bending deformation affected the knee region at the time. Five experiments were performed in the shearing setup and another five in bending setup. The peak values of the shearing force and the bending moment related to the damage of knee ligaments and bone fractures were calculated at the knee joint level. Damages were assessed by dissecting the lower extremity. When the knee joint was exposed to the “purest possible shearing deformation”, the common initial damagemechanism was ligament damage related to ACL (60% of cases).

Pregnant occupants pose a particular challenge to safety engineers because of their different anthropometry and the additional “occupant within the occupant.” A detailed study of the anthropometry and seated posture of twentytwo pregnant drivers over the course of their pregnancies was conducted. Subjects were tested in an adjustable seating buck that could be configured to different vehicle package geometries with varying belt anchorage locations. Each subject was tested four times over the course of her pregnancy to examine changes in seat positioning, seated anthropometry, and positioning of the lap and shoulder belts with gestational age. Data collected include preferred seating positions of pregnant drivers, proximity of the pregnant occupant to the steering wheel and airbag module, contours of the subjects’ torsos and abdomens relative to seat-belt centerline contours, and subject perceptions of their seated posture and proximity to vehicle components.

Cadaver data from experiments and data from field studies collected for the purposes of risk analysis are almost always censored. If the form of the underlying distribution is known, then the best method of analysis is to estimate the parameters using a maximum likelihood approach, but if it is not known, the best method is a non-parametric approach. The Consistent Threshold Estimate, introduced in this paper, is a method to estimate the underlying distribution that is both non-parametric and a maximum likelihood estimate. In this paper, we will use it to estimate threshold HIC values for skull fracture or tissue damage, but it can be used for any application that has censored data. In addition to mathematically defining the Consistent Threshold estimate, a simple method to compute it for doubly censored data is given and it is compared to other estimators by means of Monte Carlo Tests. The Consistent Threshold estimate is then applied to experimental head impact to cadaver data.

The objective of this research is to clarify the significant factors causing AIS 2+ femur or pelvis pedestrian injury, and to understand whether the current EEVC upper legform test reflects real world pedestrian accidents. An in-depth case study was conducted using the selected 82 pedestrian accident cases from 1987 to 1997 in the data base of Japan Automobile Research Institute (JARI) and Institute for Traffic Accident Research and Data Analysis (ITARDA). The results indicate the significant factors were the bonnet leading edge height, the vehicle registration year and the pedestrian age. The bumper lead was not a significant factor. However, the test condition of the EEVC upper legform test depends on the bumper lead and the bonnet leading edge height. The current test condition of the EEVC upper legform test should be reconsidered excluding the bumper lead.

The need to perform thermal analysis for automotive lamps has increased in recent years, due to the use of plastics for the lens and housing materials. Tremendous advances have been made in finite element analysis methods for solving coupled specular surface radiation and natural convection with an unstructured mesh. Headlamp temperature rise predictions were made using the ADINA-F CFD code. The results showed very close agreement between the predicted and measured lens and housing temperatures with an accuracy of +/-10 percent. The successful benchmarking of the lamp thermal model has allowed the analysis method to be applied to a wide variety of lamp designs and operating conditions which has reduced the cost of products and development.

Design Sensitivity Analysis (DSA) is applied to a thermal data base for automotive lamps. The DSA predicts temperatures on lamps with dimensions and light sources different from those in the data base. Predicted temperatures closely agree with the measured temperatures. These predictions are done early in the design phase and allow use of a Cardinal thermal data base than a Conventional one. The DSA can also be used in designing lamps for thermal safety.

It is believed that the driver's color appearance in his visual field illuminated by the headlamps at night is similar to the mesopic vision. In this study, therefore, we attempted to experimentally clarify how colors are appeared when the headlamps are turned on at night. Processing the results of this experiment with a color engineering technology, we attempted to reproduce the color appearance of scene during nighttime driving. The purpose of this study was to reproduct the appearance of colors during nighttime driving on the basis of ones in the daytime. By this reproduction, the night driving safety and the visibility of the headlamp evaluation are expected to be improved.

The most important changes in signal lamps took place in the '90s, with the introduction of new, alternative light sources. Light-emitting diodes and neon tube systems were able, for the first time, to concomitantly achieve freedom from maintenance and new design via their use in Center High Mounted Stop Lamps (CHMSL), side-marker lamps and rear panels. This paper presents a comparison of the technological and economic performance of contemporary signal lamp light sources, and attempts to provide a perspective of developments over the forthcoming years.

In this paper we will present results on the investigation and testing of a new category of discharge lamps. These lamps are based on low-pressure rare gas discharges. The evaluation of potential phosphor materials compatible with these discharges represents an important aspect of lamp design. In this paper we will present experimental results on the electrical and photometric properties of lamps utilizing a variety of phosphor materials.

This paper will describe the procedures that will enhance the possibilities of qualitative evaluation of headlamp light distributions. A basis will be the description of a light distribution coming only from reflector geometries, i.e. headlamps with clear outer lens design. Further steps of evaluation, as visualization and homogeneity analysis become more and more important for a headlamp evaluation. The recently developed tools can support both the headlamp manufacturer and the car manufacturer in finding a common understanding in headlamp performance of a projected car at a very early stage of development.