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The purpose of this study was to determine the optimal location of the shoulder belts for a suspender style four-point safety belt system. This optimal location must satisfy two conditions. First, the shoulder belts must properly fit over the occupant’s shoulders for safety performance. Second, the shoulder belts location on the occupant’s body must be acceptable to the occupant. To determine the optimal acceptable location of the shoulder belts, forty-four subjects were recruited by height and tested in a reconfigurable test seat. The results showed that avoiding an interaction between the shoulder belts and the occupant’s neck improved the acceptability of the system. Variables that affected this interaction included the horizontal and vertical position of the shoulder belts and the occupant’s weight, clothing, and gender.

Locations of key body segments of Hybrid III dummies used in FMVSS 208 compliance tests and NCAP tests were measured and subjected to statistical analysis. Mean clearance dimensions and their standard deviations for selected body segments of driver and passenger occupants with respect to selected vehicle surfaces were determined for several classes of vehicles. These occupant locations were then investigated for correlation with impact responses measured in crash tests and by using a three dimensional human-dummy mathematical model in comparable settings. Based on these data, the importance of some of the clearance dimensions between the dummy and the vehicle surfaces was determined. The study also compares observed Hybrid III dummy positions within selected vehicles with real world occupant positions reported in published literature.

The increased focus on occupant protection by automobile manufacturers combined with incessant consumer demand for safety features such as dual airbags has posed design engineers with major challenges in the field of Instrument Panel (IP) design. Typically, airbags are designed to deploy when the speed of the automobile is above 13 mph in a frontal impact. The airbag door should meet head impact requirements for unbelted occupants involved in low speed impacts (<15mph) when airbags are not deployed. This paper describes how computer aided engineering (CAE) simulation techniques were used in improving the design of the passenger airbag door of a full size van for head impact performance. Fewer tests were conducted primarily for validation, which resulted in significantly less prototypes, costs and time.

During frontal and rear end type collisions, very large forces will be imparted to the passenger compartment by the collapse of either front or rear structures. NCAP tests conducted by NHTSA involve, among other things, a door openability test after barrier impact. This means that the plastic/irreversible deformations of door openings should be kept to a minimum. Thus, the structural members constituting the door opening must operate during frontal and rear impact near the elastic limit of the material. Increasing the size of a structural member, provided the packaging considerations permit it, may prove to be counter productive, since it may lead to premature local buckling and possible collapse of the member. With the current trend towards lighter vehicles, recourse to heavier gages is also counterproductive and therefore a determination of an optimum compartment structure may require a number of design iterations. In this article, FEA is used to simulate front side door behavior.

Injury to the thorax is the predominant cause of fatalities in crash-involved automobile occupants over the age of 65, and many elderly-occupant automobile fatalities occur in crashes below compliance or consumer information test speeds. As the average age of the automotive population increases, thoracic injury prevention in lower severity crashes will play an increasingly important role in automobile safety. This study presents the results of a series of sled tests to investigate the thoracic deformation, kinematic, and injury responses of belted post-mortem human surrogates (PMHS, average age 44 years) and frontal anthropomorphic test devices (ATDs) in low-speed frontal crashes. Nine 29 km/h (three PMHS, three Hybrid III 50th% male ATD, three THOR-NT ATD) and three 38 km/h (one PMHS, two Hybrid III) frontal sled tests were performed to simulate an occupant seated in the right front passenger seat of a mid-sized sedan restrained with a standard (not force-limited) 3-point seatbelt.

In the 1999 Supplemental Notice for Proposed Rulemaking (SNPRM) for Advanced Airbags, the National Highway Traffic Safety Administration (NHTSA) sought comments on the maximum speed at which the high-speed, unbelted occupant test suite will be conducted, i.e., 48 kph vs. 40 kph. To help address this question, an analysis of constraints was performed via extensive mathematical modeling of a theoretical restraint system. First, math models (correlated with several existing physical tests) were used to predict the occupant responses associated with 336 different theoretical dual-stage driver airbag designs subjected to six specific Regulated and non-Regulated tests.

The paper describes the use of strain gauge goniometers to measure dummy leg joint angles in impact tests. The instruments have been developed based on regular goniometers used for human gait analysis. Specific modifications enhanced the mechanical stability and the electrical insulation of the sensors. They are now compatible with standard crash data acquisition systems. Several vehicle crash tests have been analyzed using the goniometers as a supplementary measurement device. Due to its low weight, the device does not significantly alter the dummy behavior. Further areas of application are outlined in the paper.

One of the major goals in the design of the new Ford Aeromax and Louisville heavy truck product line was to achieve competitive leadership in visibility. Market research found that visibility was an important issue to the heavy truck driver. Visibility is defined as both direct and indirect (i.e., the driver's ability to see with and without the use of supplemental vision devices such as mirrors) and both interior and exterior. The scope of this paper includes the work which was accomplished in evaluating direct and indirect exterior visibility and the resulting vehicle design which achieved Ford's leadership goals. Poor weather visibility and interior vision are beyond the scope of this paper. Polar Plots were the method of choice in the Aeromax/Louisville visibility studies. Industry acceptance of these techniques has been established in the recent approval of SAE J1750, “Evaluating the Truck Driver's Viewing Environment”.

The influence of calcium treatment on the mechanical properties of a plain carbon steel (SAE 1050) was investigated. The mechanical properties investigated were tensile and impact strength, fatigue crack growth rate, and the fatigue threshold. Impact testing was conducted at both room temperature and at -40°C. Several heats of both calcium and non-calcium treated steel (SAE 1050) were tested in both the as hot-rolled condition and in the quenched and tempered condition (with a hardness level of HRC = 45). The results of this investigation show no significant difference in the tensile properties or room temperature impact properties between the calcium treated and the non-calcium treated steels. However, the impact strengths of calcium treated steels were slightly higher than that of non-calcium treated steels at -40°C.

The SAE Recommended Practice J963 “Anthropomorphic Test Device for Dynamic Testing” describes a standard 50th percentile adult male anthropomorphic test dummy. For nearly three years the Crash Test Dummy Task Force worked with the limited data available in selecting values for the body dimensions and ranges of motion. The data for specifying the values of mass distribution were developed experimentally as was a test procedure for determining the dynamic spring rate of the thorax.

A laboratory study was performed to assess the effects of sulfur poisoning and desulfation temperature on the NO conversion of a LNT+(Cu/SCR) in-situ system. Four LNT+(Cu/SCR) systems were aged for 4.5 hours without sulfur at 600, 700, 750, and 800°C using A/F ratio modulations to represent 23K miles of desulfations at different temperatures. NO conversion tests were performed on the LNT alone and on the LNT+SCR system using a 60 s lean/5 s rich cycle. The catalysts were then sulfur-poisoned at 400°C and desulfated four times and re-evaluated on the 60/5 tests. This test sequence was repeated 3 more times to represent 100K miles of desulfations. After simulating 23K miles of desulfations, the Cu-based SCR catalysts improved the NO conversion of the LNT at low temperatures (e.g., 300°C), although the benefit decreased as the desulfation temperature increased from 600°C to 800°C.

STYLING the Continental Mark II with a very low silhouette without sacrificing leg room, seating comfort, and driver visibility was accomplished by using a specially designed frame and a 3-joint driveline. These two features are the basic engineering innovations which make possible the Continental's distinctive classic styling. As a result of this structural analysis, Ford has produced an automobile that, according to the author, has technical advancements that are of value to the consumer.

Statistical Energy Analysis (SEA) is being actively pursued in the automotive industry as a tool for vehicle high frequency noise and vibration analysis. A D-class passenger car SEA model has been developed for this purpose. This paper describes the development of load cases for the SEA model to simulate road noise on rumble road. Chassis roll test with rough shells was performed to simulate rumble road noise. Sound radiation from tire patch and vibration transmission through spindles were measured to construct the SEA load cases. Correlation between SEA model predictions and measured data was examined. Test and SEA result comparisons have shown that simulation of airborne road noise requires only a trimmed body SEA model, while simulation of structure-borne road noise may require SEA modeling of chassis components.

The European safety regulation plan regarding frontal barrier offset impact calls for 30° angular impact protection in 1995 and a perpendicular 40% offset deformable barrier impact protection in the 1998 time frame. However, various other governmental and private agencies are looking at alternative test conditions. The Auto Motor and Sport Magazine and other insurance agencies have been conducting rigid barrier front impact tests at 40 and 50% offsets. In this study various test conditions were examined analytically. Detailed finite element models were developed to understand the implications of these impact conditions. The models provided insight into energy management mechanism, load transfer and vehicle deformation patterns due to offset impacts on to perpendicular and angular barriers. Several potential offset conditions were simulated using the FEA models.

In an attempt to predict the responses of side crash pressure sensors, the Corpuscular Particle Method (CPM) was adopted and enhanced in this research. Acceleration-based crash sensors have traditionally been used extensively in automotive industry to determine the air bag firing time in the event of a vehicle accident. The prediction of crash pulses obtained from the acceleration-based crash sensors by using computer simulations has been very challenging due to the high frequency and noisy responses obtained from the sensors, especially those installed in crash zones. As a result, the sensor algorithm developments for acceleration-based sensors are largely based on prototype testing. With the latest advancement in the crash sensor technology, side crash pressure sensors have emerged recently and are gradually replacing acceleration-based sensor for side impact applications.

An Arbitrary Lagrangian Eulerian (ALE) approach was adopted in this study to predict the responses of side crash pressure sensors in an attempt to assist pressure sensor algorithm development by using computer simulations. Acceleration-based crash sensors have traditionally been used to deploy restraint devises (e.g., airbags, air curtains, and seat belts) in vehicle crashes. The crash pulses recorded by acceleration-based crash sensors usually exhibit high frequency and noisy responses depending on the vehicle's structural design. As a result, it is very challenging to predict the responses of acceleration-based crash sensors by using computer simulations, especially those installed in crush zones. Therefore, the sensor algorithm developments for acceleration-based sensors are mostly based on physical testing.

With a goal to help develop pressure sensor calibration and deployment algorithms using computer simulations, an Arbitrary Lagrangian Eulerian (ALE) approach was adopted in this research to predict the responses of side crash pressure sensors for unitized vehicles. For occupant protection, acceleration-based crash sensors have been used in the automotive industry to deploy restraint devices when vehicle crashes occur. With improvements in the crash sensor technology, pressure sensors that detect pressure changes in door cavities have been developed recently for vehicle crash safety applications. Instead of using acceleration (or deceleration) in the acceleration-based crash sensors, the pressure sensors utilize pressure change in a door structure to determine the deployment of restraint devices. The crash pulses recorded by the acceleration-based crash sensors usually exhibit high frequency and noisy responses.

In an attempt to assist pressure sensor algorithm and calibration development using computer simulations, an Arbitrary Lagrangian Eulerian (ALE) approach was adopted in this study to predict the responses of side crash pressure sensors for body-on-frame vehicles. Acceleration based, also called G-based, crash sensors have been used extensively to deploy restraint devices, such as airbags, curtain airbags, seatbelt pre-tensioners, and inflatable seatbelts, in vehicle crashes. With advancements in crash sensor technologies, pressure sensors that measure pressure changes in vehicle side doors have been developed recently and their applications in vehicle crash safety are increasing. The pressure sensors are able to detect and record the dynamic pressure change when the volume of a vehicle door changes as a result of a crash.

Seatback strength and injury potential in moderate to high-speed rear-end collisions were investigated in a series of 12 HYGE sled tests. The test methodology included the use of instrumented Hybrid-III anthropomorphic test devices (ATDs). Four tests employed a 95th percentile male ATD ballasted to a total weight of 300 lbs and subjected to approximate 15 mph Delta-V impacts. The remaining tests employed an unmodified 50th percentile male ATD with impacts of approximately 25 mph Delta-V, and three ATD positions, including two "out of position" postures corresponding to leaning forward ("forward" position), and leaning forward and inboard ("radio" position). Seats from three different vehicles were tested, representing a range of strength values. Upper neck values for N were less than 1.0 in all cases. Lower neck N values sometimes exceeded 1.0 with the 50th percentile male ATD out of position, and these values did not trend with seatback strength.

The past, current and future role of electronics in reducing accidents, crash severity and crash notification is discussed. A holistic approach that ties pre-crash, crash and post-crash factors in enhancing automotive safety is examined and the growing role of electronics in affecting the three factors is discussed. Electronic technology has already entered the automotive safety arena, and its utilization in the future is expected to grow rapidly towards the goal of safer roadway environment.