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Damage analysis methods in accident reconstruction use an estimate of vehicle stiffness together with measured crush to calculate crush energy, closing speed, and vehicle delta-V. Stiffness is generally derived from barrier crash test data. The accident being reconstructed often involves one or more conditions for which vehicle stiffness is not well defined by existing crash tests. Massive moving barrier (MMB) testing is introduced as a tool to obtain additional and accident specific stiffness coefficients applicable for reconstruction. The MMB impacts a stationary vehicle of similar structure as the accident vehicle under accident-specific conditions like impact location, angle, over-ride / under-ride, offset and damage energy. A rigid or deformable structure is mounted to the front of the MMB, representative of the impacting structure in the accident. Four illustrative tests are presented.

Wheels and tires on vehicles, are often directly (or indirectly) involved in collisions with other vehicles or fixed objects. In this study, the effects of the pneumatic tire and rim, as it contributes to a dynamic collision, was isolated and studied. A total of 15 mounted tires of various common sizes were selected to conduct 35 dynamic impact tests into the flat face of an instrumented concrete barrier. The tires and rims used in the tests ranged from heavy truck, light truck, down to common passenger vehicle tires. Each of the 15 tires and rims were impact tested individually to failure in order to explore the dynamic response and performance of pneumatic tires in collisions. Of the 35 tests, 28 were conducted with a single tire and rim configuration and 7 tests were conducted simulating a dual truck tire configuration. It was determined that the coefficient of restitution for 22 of the tire impacts into the rigid flat faced barrier were remarkably similar, around 0.9 ± 0.1.

The rear override crash behavior of full-size and light duty pickup trucks was examined. A series of ten full-scale, front and rear override impact crash tests were conducted involving four full-size pickup trucks, two light duty pickup trucks, and one sport utility vehicle (SUV). The tests were conducted utilizing a fabricated steel rigid barrier mounted on the front of the Massive Moving Barrier (MMB) test device with full overlap of the test vehicle. Crush ranged from 25.0 to 77.9 inches for impact speeds of 21.7 to 36.0 mph. These override tests on pickups were conducted to provide more basis in an area that is underrepresented in the literature. Each test was documented and measured prior to, and following, the crash test. The stiffness parameters were calculated and presented using constant stiffness, force saturation, and the power law damage models.

Nine crash tests were conducted at various speeds on three vehicles in three locations under conditions that resulted in similar damage. The objective was to study the differences in crash pulse, deltaV, crush depth, and impact location with change in closing velocity from 20 to 55 mph. Three equal-weight Nissan Sentra vehicles were impacted in the front, rear, and side by an associated narrow object impact device. The three impactors were identically shaped, flat-faced, one-foot wide, and rigid; but each was designed to have a different weight (light, moderate, and heavy weight). The heavy, moderate, and light weight impactors collided with their associated test vehicle at low, medium, and high impacting speeds, respectively, in order to produce damage corresponding to a 20 mph BEV (Barrier Equivalent Velocity) in all nine tests. Impacts at the same location on the three vehicles produced nearly identical damage yet substantially differed in deltaV.