Comparison of frontal crash test pulses

The severity of the full frontal rigid barrier test and sled test is compared to that of the vehicle-to-vehicle crash test.

The complexity of real-world vehicle-to-vehicle (VTV) crashes cannot be captured completely by the metric used by the National Highway Traffic Safety Administration (NHTSA), which is based on average acceleration and pulse duration. However, a large part of a recent study followed an NHTSA-like approach to compare VTV crash test pulses with those from single-vehicle crash tests, and the American Automobile Manufacturers Association (AAMA) sled test. Data from the Federal Motor Vehicle Safety Standard (FMVSS) 208 full frontal rigid barrier test and the VTV crash tests were taken directly from NHTSA's website. Transport Canada and the Insurance Institute for Highway Safety (IIHS) provided the offset deformable barrier impact data. The full frontal fixed deformable barrier (FFFDB) tests and the offset rigid barrier tests were conducted by DaimlerChrysler. The deformable element of the moving barrier used in FMVSS 214 tests was used in the FFFDB tests.

The average acceleration was considered to be the total change in velocity during the crash test divided by the time it took for acceleration to reach zero. It should be noted that accelerometer drift, vehicle rotation, and accelerometer misalignment could influence time measurements, corrupting the conclusions. Figure 1 shows comparisons of different crash tests in terms of their relationship between the average acceleration and the pulse duration. The data are relatively limited for each test except the FMVSS 208 test. Also, the data are from cars made in different years, spanning nearly 10 years. The older cars could potentially be larger in size and mass. There could also be a substantial difference in the kind of steel used between the new cars and the older cars. These differences can lead to increased scatter in the data.