Citation

Rains G, Van Voorhis M. Accid. Reconstr. J. 2001; 12(5): 35-46.

Copyright

(Copyright © 2001, Accident Reconstruction Journal)

DOI

unavailable

PMID

unavailable

Abstract

In an effort to reduce injuries to vehicle occupants by roof intrusion in rollover accidents, the National Highway Traffic Safety Administration is considering upgrading Federal Motor Vehicle Safety Standard (FMVSS) 216. Currently, this standard sets requirements for roof crush resistance using a quasi-static load applied to the vehicle roof. This load application has been criticized as not representative of real-world loading rates of roof structures in a rollover incident. This study examines roof crush resistance in passenger vehicles in order to determine the correlation between roof crush performance measured quasi-statically and dynamically. Tests comparing quasi-static roof loading versus dynamic roof loading were conducted to determine how static and dynamic tests can be correlated and if the static test can be transformed to a dynamically equivalent result. Nine vehicles were subjected to quasi-static tests and then ranked for performance based on roof strength and stiffness. Six vehicles of these vehicles were then subjected to a dynamic drop test. Dynamic force versus crush, and energy versus crush were plotted. Energy plots from the quasi-static and the dynamic testing were then compared. The slopes of the dynamic test were 1.1 to 1.6 times the static crush slopes for all six vehicles. A multiple regression of static and dynamic testing was performed to develop an equation for predicting a dynamic energy slope from static data. The equation had a correlation coefficient of 0.94. The equation was validated by crushing the roof of another vehicle quasi-statically. Results show that the current standard could be improved by a static test that is transformed into a dynamically equivalent result, and that this transformation could be based on a static to dynamic roof energy calculation.