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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.

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.

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.

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.

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.

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.