impact location, and enough energy remained to fail the transmission mount cross member. The cross member buckled downward and struck the ground. The severe deformation led to direct contact with the monorail guidance carriage. The carriage was mounted to the truck with small bolts, which allowed the carriage to break away without damage or significant contribution to the truck’s undercarriage performance. The front end and bed of the pickup truck moved independently; the bed continued to wrap around the pole and struck the load cells bolted to the back face of the rigid pole. The wrapping action of the front end and bed was stopped by the pole itself. The width of the door was reduced to the diameter of the pole impact faces before rebounding. Double integration of the c.g. acceleration trace for the total event time yielded a maximum deflection of 1.0 m. Double integration of the c.g. acceleration trace, for the time up to when the cab started to rotate and became dislodged from the frame, yielded a maximum deflection of 840 mm. Both accelerometer deflection values may be exaggerated due to the extreme buckling of the floor pan and floor tunnel. The maximum static deflection measured after the test was 1156 mm. However, the points used to position the reference plane for measuring the post-test profile had been displaced. The distance between the two parallel longitudinal frame rails before the test was
1140 mm, and after the test, the frame rails were 510 mm apart. The static deflection of the left frame rail was 630 mm. The total frame rail deflection cannot be equated to the occupant compartment deformation because the cab dislodged from the frame. The cab was displaced approximately 305 mm (static measure). The interior distance between the doors was 1730 mm before the test and 995 mm afterward, which indicates a static intrusion of 735 mm. As the C-shape frame rail deflected, one leg of the C-shape ripped a hole in the fuel tank located on the left side of the vehicle and inboard of the frame rail.
Damage to the pickup truck was extensive. The driver door caved, the B-pillar drew inward, the windshield shattered, the dashboard and bench seat buckled, the left frame rail bent and punctured the fuel tank, the transmission mount cross member buckled, the aluminum drive shaft bent, and the cab dislodged from the frame mounts. The passenger door latch failed, which allowed the door to swing open. The driver door remained latched. The peak lateral c.g. acceleration recorded was
30.4 g’s (595,000 N) and occurred 0.0494 s after impact. Table 8 lists the positive and negative peak accelerations from each vehicle accelerometer.
Sensor |
Maximum positive (g’s) |
Maximum negative (g’s) |
| C.g. accelerometer Ax, primary | 12.3 |
-13.6 |
| C.g. accelerometer Ay, primary | 5.5 |
-30.4 |
