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Assuming rigid body motion, recorded acceleration and recorded roll rates at the center of gravity, equations are used to calculate the local three-dimensional accelerations at hypothetical seating positions' Emergency Locking [seat belt] Retractors (ELR) during a steer induced rollover crash. For a threshold of 0.7 g, results demonstrated that intervals in the vehicle's response that may cause the ELR's inertial sensor to move into a neutral zone were limited to localized high magnitude negative vertical acceleration events during the rollover segment with a median duration of 4 ms, average duration of 4.8 ms and a maximum calculated duration of 31.7 ms. Changing the threshold to 0.35 g reduced the interval count by 70 percent and maximum duration by approximately 50 percent.

The current certification requirements under CFR 49, Part 567 state that GVWR of a motor vehicle shall not be less than the sum of the unloaded vehicle weight, rated cargo weight and 150 pounds times the number of designated seating positions. Actual occupant weight distributions versus certified weight per occupant seat causes a potential conflict between a vehicle's in-use weights versus its certified GVWR. Population weight distributions were developed based upon The Center for Disease Control's (CDC) publication of 2007 - 2010 anthropometric reference data and publically available weights of a special population from high school football teams. For five buses from small (18-seat) to large (55-seat), key parameters were measured.

The Federal Aviation Administration (FAA) and Coast Guard recently adapted increases in the average passenger weight used to calculate load and conduct safety analysis and tests in multiple modes of transportation. The Federal Transit Authority (FTA) has proposed similar measures. The increased passenger weight requirements were created in response to the Center for Disease Control's (CDC) documented rise in weight among the country's citizens and followed crash or failure incidents in which a cause was overweight equipment. The current certification requirements under CFR 49, Part 567 state that Gross Vehicle Weight Rating (GVWR) of a motor vehicle shall not be less than the sum of the unloaded vehicle weight, rated cargo weight and 150 pounds (68 kg) times the number of designated seating positions. Actual occupant weight distributions versus certified weight per occupant seat causes a potential conflict between a vehicle's in-use weight versus its certified GVWR.

Recreational Off-Highway Vehicles (ROVs) are a distinct class of vehicles defined by an American National Standard (ANSI). The vehicles are intended primarily for recreational use and may have secondary general utility applications. The American National Standard (ANSI) for Recreational Off-Highway Vehicles addresses minimum requirements for aspects of ROV equipment and configuration, but includes no discussion regarding the design or performance of ROV fuel systems. The purpose of this study was to: survey pre- and post-ANSI Standard designs of ROV fuel systems; examine fuel system design recommendations and requirements for other types of fueled motive equipment, including diverse types of recreational equipment; and describe the environment in which the ROV was intended and the environment in which it was legal for use.

A variable deceleration rate approach to rollover crash reconstruction was proposed in 2009 by Rose and Beauchamp. A detailed description of Rose and Beauchamp's method was outlined in 2010. The method used a Linearly Variable Deceleration Rate (LVDR) as a function of roll distance. Improvements in responses as a function of time was demonstrated by Rose and Beauchamp using test data from two 208 dolly rollover tests; however, they noted that additional validation work using steering-induced rollover tests would be desirable. This paper provides additional validation of the LVDR model using the steer-induced rollover test data reported in 2011 by Stevens et al. The Over-The-Ground Speed (OGS) and recorded roll rate results from the five steer-induced rollover tests reported by Stevens' in 2011 were compared to reconstructed speed and roll rates as a function of time using the 2010 Rose and Beauchamp LVDR method.

A series of rollover tests was conducted in a real-world environment in which a vehicle was driven or towed to highway speed then steered to induce a rollover. This research presents analysis of the rollover phase of five tests. In each test, the steering maneuver was initiated on-pavement, and the rollover was caused by tire-to-ground interaction. Tests included vehicles that tripped both on-pavement and on soil. Four tests ended with the vehicle at rest off-road, and one ended with the vehicle remaining on the pavement. A programmable remote control radio was used to steer the vehicles through a double-step steer maneuver to result in a rollover. The test vehicles were instrumented and data was collected during each test, including steering, suspension motion, rotational rates, and accelerations. A Global Positioning System (GPS) speed sensor (VBOX III manufactured by Racelogic) was used to monitor the vehicle speed. Data from all tests is presented in the Appendix .

An instrumented 2005 Ford Explorer was used to evaluate speed data provided from its Powertrain Control Module (PCM) at high slip angles. PCM speed was compared to speed and slip angle collected from a calibrated Datron S-400 velocity sensor. In addition to speed, slip angle and other standard handling test measurements the vehicle brake switch and throttle were recorded so PCM data could be synchronized. After each test run the vehicle ignition was turned off and the PCM was downloaded using commercially available Bosch hardware and software. The principal maneuver was the National Highway Traffic Safety Administration (NHTSA) sine-with-dwell test consisting of a 0.7 HZ sinusoidal steer with a 0.5 second dwell at the steer reversal peak. Runs were conducted with the vehicle’s Electronic Stability Control (ESC) disengaged so that the test vehicle would achieve large slip angles.

Electronic Stability Control (ESC) has the potential of improving yaw stability and reducing the occurrence of a crash when a vehicle experiences a rear tire tread separation. Two instrumented 4-door, RWD SUV’s equipped with ESC were tested to evaluate the effectiveness of their ESC systems on maintaining yaw stability under these circumstances. The test vehicles were evaluated with the tread and outer steel belt removed from the right rear tire. Tests were run with the ESC engaged and then repeated with the ESC disengaged. All runs were completed with the tires inflated to the manufacturer’s recommended pressure. An analysis of the data collected shows that there are significant differences in the steering input required to generate a loss of control response with and without ESC enabled. Results of Sine with Dwell testing demonstrate a significant reduction in vehicle spinout response with the ESC engaged.

Temporary-use-only spare tires are common standard equipment on motor vehicles while run-flat tires are offered as standard equipment on some motor vehicles. This paper describes testing on a 1995 GMC Safari all-wheel-drive minivan with a rear Uniroyal Hideaway / Temporary-Use-Only tire and a 1997 Mercury Grand Marquis with a self-supporting run-flat tire manufactured by Bridgestone. The testing included circle turn tests and 180° step steer tests at target speeds of either 30 or 35 miles per hour (low speed J-turn test). Control tests were conducted with standard normally inflated tires. Both the standard tires and run-flat tires were also tested in a modified condition involving the removal of the tread and outer steel belt, simulating a tire which has experienced a complete tread-belt separation.

Tests were conducted to evaluate the effects of the tire-induced vibration caused by a tread separating rear tire on the handling characteristics of a 1996 four-door two-wheel drive Ford Explorer. The first test series consisted of a laboratory test utilizing a 36-inch diameter single roller dynamometer driven by the rear wheels of the Explorer. The right rear tire was modified to generate the vibration disturbance that results from a separating tire. This was accomplished by vulcanizing sections of retread to the prepared surface of the tire. Either one or two tread sections covering 1/8, 1/4, or 1/2 of the circumference of the tire were evaluated. The results demonstrated that a tire modified with two bonded-on tread sections driven at half speed replicated axle tramp characteristics of a modified tire with a single bonded-on tread section at the peak axle tramp speed.

A series of tests were conducted utilizing a tire test machine built to measure forces during a tire tread separation event. Tires were prepared by cutting between the two steel belts inward from the shoulder area. Cuts were varied in size and location to generate different types of tread separation events (ex: long, short, partial, inboard, and outboard). The tests document the longitudinal and lateral forces generated while the tread is detaching during different types of tread separation events. The results demonstrate that magnitude and duration of forces depend upon the nature of the tread separation event. Additional documentation includes high speed and real time video of the tread separation events to provide insights into tread detachment modes and mechanisms of measured force response.

Using analysis of a mini-van test vehicle’s static load conditions as a guide, four different vehicle loading situation were constructed. The loading situations represent the corners of the vehicle’s center of gravity position envelope. For the testing described in this paper a single vehicle under conditions of varied load was subjected to a series of test maneuvers designed to elicit objective measure and comparison of vehicle steady-state and transient response. The purpose of this paper is to describe the test method and present the results of handling testing and limit stability testing of a 1991 Ford Aerostar mini-van/extended van under four different loading conditions. Differences observed in the plotted results of vehicle steady state response for different load condition are detectable, but small. The test results demonstrate differences in vehicle transient response for different loading configuration.

Catastrophic and sudden tire tread separation is an event that drivers of motor vehicles may encounter and, in some instances, is implicated as the cause of motor vehicle crashes and related injury or property damage. In an effort to understand how tire tread separation affects vehicle handling, a series of tread separation handling test programs were conducted. In each tread separation test program a sport utility vehicle was instrumented and equipped with steel belted radial tires that were modified to emulate tread separation between the inner and outer steel belts. The test vehicle was then subjected to a variety of open and closed loop handling test maneuvers. This paper presents the data and analysis from these tests. The research demonstrates through controlled experiments that a tire tread separation has an effect on the vehicle’s fundamental handling characteristics. It also demonstrates that the effect depends on the position of the compromised tire on the vehicle.

To date, the flammability of common automotive fluids under real-world conditions has not been well characterized for general use in the automotive community. This paper presents the results of a research program aimed at providing a greater understanding of the potential fire hazards of common fluids carried on board today's vehicles. A literature review was conducted to define the ignition properties of common automotive fluids as determined very precisely in the lab environment. A test program was then established to gain insight into the ignition properties of common automotive fluids under some real-world conditions. Automotive engine and exhaust components were used to create a test mechanism which realistically represented the environment, temperatures, and surfaces to which vehicle fluids may be subjected The reported laboratory results are compared to the test data. Tests were conducted on twelve fluids with and without ignition sources present.