EFFECT OF TUMBLE-HOME ON ROOF STRENGTH OF A VEHICLE

SEO, J. H.; LEE, E. D.; LEE, J. W.; HAN, B. K.

doi:2016.17.4.665

International Journal of Automotive Technology > Volume 17(4); 2016 > Article

Automobile Body and Safety

International Journal of Automotive Technology 2016;17(4): 665-670.
doi: https://doi.org/10.1007/s12239-016-0065-2

EFFECT OF TUMBLE-HOME ON ROOF STRENGTH OF A VEHICLE

J. H. SEO¹, E. D. LEE², J. W. LEE², B. K. HAN¹

¹Hongik University
²TS

ABSTRACT

This study reports on the effect of vehicle tumble-home (side body inclination) on roof strength. The steep inclination of the side body of a vehicle increases its roof strength. Comprehensive analysis of the impact of high roof strength driven by the steep inclination on dynamic roof strength in rollover is described. Here, we have developed a numerical model using the ADAMS, which is capable of characterizing both of the static and the dynamic roof strength. According to the FMVSS 216 protocol, we achieve the strength to weight ratio (SWR; static roof strength) by applying loading plates to the roof of a vehicle. The Controlled Rollover Impact System (CRIS) allows us to quantitatively characterize the displacements of the top end of A-pillar and B-pillar, thus determining the dynamic roof strength by comparing the results. We demonstrated that the roof intrusion was one of the most critical causes which lead to injuries of occupants fastening seat belts. Our analysis revealed that the increase of the side body inclination of vehicles enhanced the static roof strength whereas it could not reduce the roof displacement (intrusion) in the dynamic rollover.

Key Words: Static roof strength, Tumble-home (inclination of side body), Dynamic rollover test (CRIS; Controlled Rollover Impact System), NHTSA (National Highway Traffic Safety Administration), IIHS (Insurance Institute for Highway Safety)