Introduction 18 18 9 22 6 9 14 9 9 et al 9 7 11 et al 1 3 5 15 12 13 2 The authors used the described data in the present study. The study’s objective was to investigate both the magnitude of and the temporal relationship between dynamic roof deformation, lap–shoulder seat belt loads, and restrained ATD neck loads in these FMVSS 208 dolly rollover tests of Ford Explorer SUVs. Materials and Methods 1 1 1 Figure 1 (a) FMVSS 208 dynamic rollover pre-test setup of SUV test B190043 on a dolly rollover cart; (b) critical dimensions of FMVSS 208 dolly  1 Table 1 Test conditions Autoliv test number Test description Data sampling rate Sampling duration Test date Accelerometer Coordinates (mm) X Y Z B190042 FMVSS 208 Rollover (VIN1FMCU24E5VUC19292) (23°; 30.5 mph) 20,000 Hz ∼13,000 ms 8/10/99 Center of gravity 2073.10 −24.50 975.00 Driver’s rail at A-pillar 2038.20 −596.10 1770.0 Driver’s rail at B-pillar 2776.40 −571.30 1863.30 Driver’s rail at C-pillar 3209.70 −580.60 1871.40 Passenger’s rail at A-pillar 2011.80 592.10 1758.60 Passenger’s rail at B-pillar 2786.60 532.60 1857.10 Passenger’s rail at C-pillar 3234.40 523.30 1868.20 B190043 FMVSS 208 Rollover (VIN1FMDU34E6VUB99290) (23°; 30.4 mph) 20,000 Hz ∼13,000 ms 8/11/99 Center of gravity 2231.0 −4.1 761.3 Driver’s rail at A-pillar 2077.2 −543.7 1626.8 Driver’s rail at B-pillar 2637.2 −535.0 1644.0 Driver’s rail at C-pillar 3436.0 572.4 1598.0 Passenger’s rail at A-pillar 2077.9 573.5 1564.7 Passenger’s rail at B-pillar 2636.5 569.7 1625.5 Passenger’s rail at C-pillar 3436.3 −543.0 1617.6 B180220 FMVSS 208 Rollover (VIN1FMDU35P5VUC14510) (23°; 30.9 mph) 12,500 Hz ∼8000 ms 12/10/98 Center of gravity 2231.0 −4.1 761.3 Driver’s rail at A-pillar 2077.2 −543.7 1626.8 Driver’s rail at B-pillar 2637.2 −535.0 1644.0 Driver’s rail at C-pillar 3436.0 572.4 1598.0 Passenger’s rail at A-pillar 2077.9 573.5 1564.7 Passenger’s rail at B-pillar 2636.5 569.7 1625.5 Passenger’s rail at C-pillar 3436.3 −543.0 1617.6 Vehicle and ATD Instrumentation 2 2 1 x y z y z y z y z y z y z y z Figure 2 (a) Exterior view of test vehicle indicating A, B, and C-pillars; (b) interior view of test vehicle—accelerometers were mounted at the roof rail-to-pillar junction at the A, B, and C-pillars for both driver and passenger sides of the Ford Explorer SUVs  x y z x y z Moment (x, y, z) x y z x y z x y z Deflection x y z F z 3 Figure 3 External camera setup  1 Data Analysis ®  Vertical and/or lateral rail acceleration peak(s) “downward” and/or inboard toward the restrained ATD External camera video images consistent with SUV roof-to-ground contact Onboard camera video images consistent with a compromise in occupant survival space (i.e., reduced headroom) F z M y M x Results Results are presented and discussed for the first full second of the roll sequence for each of the three SUV tests, which includes the initial driver-side-to-ground contact and full roof contact, followed by the first passenger-side-to-ground contact. In all three tests, the external high-speed cameras recorded continuous roof-to-ground contact from the first contact of the driver’s roof rail with the ground until the end of the 1000 ms period, which corresponded to approximately 5/8 roll. Onboard high speed video cameras recorded the front passenger compartment of each SUV, capturing the kinematics of the ATDs as well as the deformation of the roof header and side roof rails during the rollover event. These cameras recorded inboard displacement of roof rails (“observable” roof crush) of both driver and passenger-side roof rails during the respective roof rail-to-ground contact for all three tests. The onboard clock, which was recorded by the interior cameras, allowed for a time-synchronized comparison of this data to the sensor output of the ATD neck transducers and roof rail accelerometers. F z 4 F z M y M x 2 Figure 4 F z  Table 2 Local Absolute Test parameter Driver Passenger B190042 B190043 B180220 B190042 B190043 B180220 F z a −958 −1962 −1920 −5933 −3245 b F z −200 −295 −223 −361 −50 200–260 M y 58 110 94 304 178 261 M y 2 11 2–54 12–22 20–24 10 M x −106 −124 −167 68 98 41 M x −11 to −18 n/a −20 to −46 9 12 19–21 a F z M y M x b F z F z M y F z F z M y M x M x 3 F z M y M x 3 5 Table 3 Time of occurrence (ms) of roof/pillar deformation and absolute maximum neck loads Test parameter Driver Passenger B190042 B190043 B180220 B190042 B190043 B180220 Objective roof/pillar deformation (vertical acceleration peaks) 497 513 510 730 a 742 Objective roof/pillar deformation (lateral acceleration peaks) 497 513 494 496 512 495 F z c 533 540 516 730 764 b M y 533 541 517 729 764 751 M x 537 548 540 783 774 760 a b F z M y 2 c F z M y M x Figure 5 F z  4 F z M y 6 7 F z M y F z M y 8 M y Table 4 Peak belt loads compared to belt loads at time of absolute maximum (peak) neck loads Test parameter Driver Passenger B190042 B190043 B180220 B190042 B190043 B180220 Peak lap belt (N) 548 (511 ms) 795 (540 ms) 940 (515 ms) 797 (599 ms) 705 (699 ms) 779 (606 ms) Peak shoulder belt (N) 395 (379 ms) a 410 (373 ms) 899 (587 ms) 953 (689 ms) a Peak F z Lap belt (N) 398 (533 ms) 789 (540 ms) 937 (516 ms)  359 (730 ms) 115 (764 ms) 771 (600 ms) Shoulder belt (N)  231 (533 ms) a 236 (516 ms) 337 (730 ms) 426 (764 ms) a Peak M y (N m) Lap belt (N) 393 (533 ms)  785 (541 ms) 937 (517 ms) 361 (729 ms) 115 (765 ms)  218 (751 ms)  Shoulder belt (N)  227 (533 ms) a 236 (517 ms) 341 (729 ms) 417 (764 ms) a a Figure 6 Driver lap belt and neck load vs. time (Test B190043)  Figure 7 Inverted 50th percentile Hybrid III Driver ATD “diving” into roof with lap and shoulder belt providing restraining forces, which reduces neck load  Figure 8 (a) Roof crush—passenger lap belt and neck load vs. time (Test B190043); (b) Roof crush—passenger shoulder belt and neck load vs. time (Test B190043)  4 F z M y 4 F z M y F z M y Discussion The three rollover tests of 1998–1999 Ford Explorer SUVs analyzed in the present study represent a unique dataset evaluating occupant dynamics in rollover crashes as represented by Hybrid III ATDs. To the authors’ knowledge, this study represents the first published test series of full-scale rollover crashes of a contemporary SUV with time synchronized sensor output from ATD neck transducers, roof rail accelerometers, an onboard high speed clock, and high speed external and internal video cameras. ATD Biofidelity 1 15 8 10 24 29 F z upper F z F z F z F z M y lower M x Injury Tolerance of the Human Cervical Spine lower 19 20 23 26 et al F z lower 1 19 24 F z M y et al 24 F z 27 4 et al 24 27 24 25 9 et al 20 et al. 26 M y M y M y M x F z M y Roof Crush as a Correlate or Cause of Injury causes associated or correlated with 1 3 5 15 16 12 13 28 F z M y M x F z M y 2 4 24 4 8 8 4 9 Figure 9 The shoulder and lap belts are off loaded (i.e., load decreases) as the roof crushes down on the passenger head and pushes the dummy back toward the seat cushion, away from the shoulder and lap belts, at the time of injurious neck loads  Repeatability and Reliability 15 F z 10 3 3 M y 11 3 3 M x Figure 10 F z  Figure 11 M y  F z F z F z F z F z F z Validity 9 21 28 M y 21 17 The results of this study provide a unique data set that furthers understanding of probable spinal column injury mechanisms within a rollover crash environment. Such information may assist the scientific community and automotive engineers in recommending and designing appropriate intervention strategies to mitigate morbidity and mortality in rollover crashes. Moreover, these data may inform government agencies in formulating appropriate public safety policy to improve rollover crash protection for restrained occupants. Conclusions F z M y