Characteristics of Trailer Rear Impact Guard - Interdependence of Guard Strength, Energy Absorption, Occupant Acceleration Forces and Passenger Compartment Intrusion
Published April 14, 2008 by SAE International in United States
Annotation of this paper is available
FMVSS 223 and 224 set standards for “Rear Impact Protection” for trailers and semi-trailers with a gross weight rating greater than 10000 pounds. A limited amount of experimental data is available for evaluating the different performance attributes of rear impact guards. The crash tests are usually limited to fixed parameters such as impact speed, guard height, strength and energy absorption, etc. There also seems to be some misunderstanding of the interdependence of guard strength and energy absorption, and their combined effect on the guard's ability to limit underride while keeping occupant acceleration forces in a safe range.
In this paper, we validated the Finite Element (FE) model of an existing rear impact guard against actual FMVSS 223 tests. We also modified a previously evaluated FE model of a 1990 Ford Taurus by updating its hood geometry and material properties. Finally, through a series of simulations, we provided insight into the interaction between guard strength, guard energy absorption, Passenger Compartment Intrusion (PCI) and the acceleration forces potentially experienced by a vehicle occupant. Performance characteristics such as strength and energy absorption were evaluated for impact speeds ranging from 25 to 50 mph involving four guard strength levels, namely a rigid guard, a minimally compliant guard, and two compliant guards with twice and thrice the strength specified in FMVSS 223.
CitationTavakoli, M. and George, V., "Characteristics of Trailer Rear Impact Guard - Interdependence of Guard Strength, Energy Absorption, Occupant Acceleration Forces and Passenger Compartment Intrusion," SAE Technical Paper 2008-01-0155, 2008, https://doi.org/10.4271/2008-01-0155.
- Zaremba, L., Wong, J. (1977), “Eliminating Automobile Occupant Compartment Penetration in Moderate Speed Truck Rear Underride Crashes: A Crash Test Program,” IIHS
- DeLeys, N., O'Ryder, M. Jr., (1971), “A Study of Heavy-Vehicle Underride Guards,” SAE 710121
- Baczynski, R., Johnson, N., (1980), “Development of Compliance Test for Truck Rear Underride Protection,” Dynamic Science Inc., Report No. 8319-80-02OA/1607.
- Texas Transportation Institute, (1980), “Performance Upgrading of Commercial Vehicle Rear Underride Guards - Volume I - Summary Report,” DOT-FH-11-9366.
- Tomassoni, J., Bell, (1980), “An Approach to Developing Underride Guard Requirements for Improved Occupant Protection,” SAE 801422.
- Bowler, D., (2000), “Underride in Fatal Rear End Truck Crashes,” SAE 2000-01-3521.
- Appleby, M., Bischoff, D., (1970), “Injuries in Underride-Override Collisions - A Clinical Study,” SAE 7000483.
- Elias, Monk, (1993), “Heavy Truck Rear Underride Protection - Final Report,” DOT-HS 808-081.
- Tomassoni, J. (1998), “A Look at Minimally Compliant Underride Guard at impact Speeds above 30 mph,” SAE 986077 or SAE 98-S4-O-09.
- “FMVSS 223: Rear Impact Guards,” U.S. Code of Federal Regulations 49 CFR 571.223
- “FMVSS. 224: Rear Impact Protection,” U.S. Code of Federal Regulations 49 CFR 571.224
- Tavakoli, M., Valliappan, P., Pranesh, A., Savage, C.Jr.,, (2007), “Estimation of Frontal Crush Stiffness Coefficients for Car-to-Heavy Truck Underride Collisions,” SAE 2007-01-0731.
- Public domain model from http://www.ncac.gwu.edu/
- NHTSA, (1990), “NHTSA New Car Assessment Program (NCAP) Frontal Barrier Impact Test of a 1990 4-Door Sedan (35mph),” DTNH22-87-D-02012, Test No. 1385.
- NHTSA, (1990), “Vehicle Safety Compliance Safety for Occupant Crash Protection,” DTNH22-88-C-01038, Test No. 1403.
- Daniel, D., (2000), “Trailer Underride Protection - A Canadian Perspective,” SAE 2000-01-3522.