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2008 ARC-CSI Crash Conference
June 2-5, 2008
Las Vegas, NV
Palace Station Hotel
ACTAR CEU's: 18
WORKSHOP: Rollovers
Presented by: Lawrence A. Wilson, P.E., Micky Gilbert and David J. Bilek, P.E.
Wilson Consulting, LLC, Gilbert Engineering and Mechanical Systems Analysis, Inc.
Abstract:
This presentation identifies and documents the physical evidence generated as a consequence of on-road, untripped SUV rollover tests. We will examine how this evidence is related to the motion of the vehicle during the pre-roll and rollover sequence.
The vehicle evidence resulting from these rollovers includes scratch patterns, tire damage, rim damage, suspension damage, window damage and roof crush. The roadway evidence includes pre-roll yaw marks, paint transfers/scrape marks, glass deposits, rim gouges, rim imprints, tire scuffs, vehicle debris, and fluid stains.
The vehicle motion was documented and analyzed during the test using video cameras. Analysis of the vehicle motion was used to determine the cause of the vehicle and roadway evidence. The vehicle dynamics during the rollover sequences were also analyzed. The rollover dynamics included number of rolls, rollover distances, speeds, accelerations, roll rates, yaw angles, and yaw rates.
The vehicles involved in the testing were a 1991 Ford Explorer XLT 4x2, a 1997 Toyota 4Runner SR5 4x2 and a 2001 Chevrolet Blazer. These tests were run using the vehicles' own engines, drive trains and brakes to accelerate and maintain speed. The vehicles' steering systems were used to control the vehicle heading and direction. Remote radio signals were used to control the accelerator, brake and steering wheel during the pre-roll phase. The Explorer test and the 4Runner test were steering-induced rollovers that incorporated a left-right steering sequence. The Blazer test will be conducted as part of the 2008 ARC-CSI Crash Conference and will involve the right front corner of a Crown VIC striking the left rear axle of the Blazer in "PIT" maneuver that will lead to rollover of the Blazer. The 4Runner test was presented in Volume 2, Issue 2 of Collision. The Explorer test was presented in Volume 2, Issue 1 of Collision.
Bio - Lawrence Wilson
Licensed Professional Mechanical Engineer specializing in vehicle accident investigation, accident reconstruction, and causation analysis.
Areas of Expertise
- Vehicle-to-Vehicle Collision Analysis – Vehicle crash tests, conservation of momentum, basic principles of physics used to determine impact severity. SMAC used, when appropriate, to analyze vehicle dynamics of collision. Vetronix Crash Data Retrieval (black box) data analyzed.
- Visibility, Site Distance, Perception-Reaction Time Analysis – Evaluation and analysis of factors that frequently contribute to the cause of accidents.
- Accident Avoidance Maneuvers – Steering and braking inputs during accident avoidance maneuvers determined and analyzed.
- SUV Rollovers – Investigated and analyzed over 300 SUV rollover accidents.
- Commercial Vehicle Accident Reconstruction –SMAC used to analyze motion of tractor-trailers involved in accidents. Design analysis of commercial vehicle under-ride guards.
- Low-Speed Collision Analysis – Limited vehicle damage, Bumper-to-bumper impacts include highly varying coefficients of restitution. Analysis based on vehicle-to-vehicle and vehicle-to-barrier tests.
- Utility Pole Impacts – Vehicle crash tests and CRASH used for damage-based analysis. SMAC used to analyze vehicle dynamics of collision. Crash data used to determine pole-placement criteria.
- Pedestrian Accident Reconstruction – Analysis using empirically-based data.
Professional Certification and Training
- Licensed Professional Engineer in Alabama and Maryland
- Certified Technician and Analyst for Vetronix Crash Data Retrieval (CDR) System, 2006.
- Commercial Vehicle Investigation and Reconstruction, Arkansas State University, Jonesboro, Arkansas, 1995
- Traffic Accident Reconstruction II, Traffic Institute, Northwestern University, Evanston, Illinois, 1993
- Traffic Accident Reconstruction I, Traffic Institute, Northwestern University, Evanston, Illinois, 1994
Academic Background
- M.S., Mechanical Engineering, University of Maryland, College Park, Maryland, 1992
- B.S., Mechanical Engineering, University of Maryland, College Park, Maryland, 1989
Activities
- Member, Society of Automotive Engineers (SAE)
- Member, Order of the Engineer, University of Maryland, College Park Chapter
- Consulted in development of syllabus and course content for graduate-level class on vehicle handling and rollovers at George Washington University in Washington, D.C.
- Guest speaker on SUV rollovers at 2006 ARC-CSI Conference in Las Vegas, Nevada, June 2006.
- Involved in untripped, on-road rollover tests of SUVs.
Bibliography of Papers
1. Wilson, L.A., M. Gilbert and D. Godrick, "Reconstruction and Analysis of Steering-Induced, On-road, Untripped SUV Rollover Tests (Part 2), Collision: The International Compendium for Crash Research, Volume 2, Issue 2, Fall 2007.
2. Wilson, L.A., M. Gilbert and D. Godrick, "Reconstruction and Analysis of Steering-Induced, On-road, Untripped SUV Rollover Tests (Part 1), Collision: The International Compendium for Crash Research, Volume 2, Issue 1, Summer 2007.
3. Wilson, L. A., D. Godrick and S. Kildare, "Vehicle Dynamic Characteristics of SUVs in On-Road, Untripped Rollover Accidents", Collision: The International Compendium for Crash Research, Volume 1, Issue 2, Fall 2006.
4. Jones, I. S., L. A. Wilson. "Techniques for the Reconstruction of Rollover Accidents Involving Sport Utility Vehicles, Light Trucks and Minivans," SAE Paper No. 2000-01-0851, SAE: International Congress and Exposition, March 2000.
5. Jones, I. S., L. A. Wilson and R. Whitfield. "Emergency Steering in Fatal and Serious Injury, Sport Utility Vehicle Rollover Crashes," IMechE, Vehicle Safety 2000, London, England, June 7-9, 2000.
Bio - David Bilek
President, Mechanical Systems Analysis, Inc. – Littleton, CO
Licensed Professional Engineer in mechanical engineering has provided consulting services in the field of mechanical and forensic engineering. Extensive knowledge, training and experience have been developed specifically in evaluating motor vehicle rollover accidents and the vehicles involved. This foundation is based in part on almost 25 years of handling and stability testing of passenger automobiles, including many SUVs. Test data and vehicle dynamics have been analyzed to assist in evaluating the adequacy of various vehicle design aspects, as well as evaluating design modifications to improve the rollover resistance performance of motor vehicles.
He has been involved with the reconstruction of single and multi-vehicle automotive accidents encompassing a large cross section of vehicles, including passenger cars, pick-up trucks, SUVs, and commercial vehicles. The majority of the reconstruction work has involved the detailed analysis of hundreds of both on and off road rollovers. However, he has also investigated, analyzed, and reconstructed accidents involving frontal, side, rear, and angled collisions between vehicles, fixed objects, and pedestrians. Occupant kinematics, or the motion of occupants when exposed to forces developed in accidents, as well as various vehicle crashworthiness issues have been routinely examined.
Computers are used extensively, including engineering and mathematical analyses, animation and simulation of vehicle dynamics, and the development and application of accident reconstruction programs.
Affiliations
- Licensed Professional Engineer - Colorado
- American Society of Mechanical Engineers (ASME)
- National Association of Professional Accident Reconstruction Specialists, Inc. (NAPARS)
- Society of Automotive Engineers (SAE)
Publications
Kaplan, M., Bilek, D., Kaplan, S., Vellos, D., Gilbert, M.,
“An Examination of Rim Gouging and Its Relation to On-Road Vehicle Rollover”,
Journal of the Society of Accident Reconstructionists; Spring 2004.
