The National Highway Traffic Safety Administration (NHTSA) routinely measures the force exerted on the barrier in crash tests. Thirty-six load cells on the face of the rigid barrier measure the force. This study examines the load cell barrier data collected during recent years of NCAP testing to determine how it can be used to assess vehicle structural crash characteristics and vehicle compatibility in car to car crashes.
Several aggressiveness metrics are proposed for different crash modes. The proposed metrics for frontal crash modes are the stiffness and the height of the center of force at 375 mm of crush, in addition to the vehicle mass.
For front-to-side vehicle crashes, some additional metrics are required. The force distribution when the loading is sufficient to cause intrusion of the side door is proposed as the basis for a metric. A high percentage of force on the lowest rows of load cells is indicative of front-to-side loading, which should be desirable. A high percentage of force on the highest rows of load cells is indicative of door intrusion in the region of the occupant's thorax, which should be less favorable. The presence of loading in the upper row of load cells at any time during the crash is indicative of a high hood, which could be the source of head impacts.
Load cell barrier measurements have been analyzed for fifty 1995-1999 vehicles tested in the NCAP program by NHTSA. This paper shows the range of the compatibility parameters measured on cars, pickups, vans, and multi-purpose vehicles. It, also, examines the relationships between measurements of geometric, stiffness and mass compatibility for frontal and frontal-offset crashes.