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This is the complete manuscript and replacement for SAE paper 2014-01-0482, which has been retracted due to incomplete content. This paper reports on 76 quasi-static tests conducted to investigate the behavior of road vehicle bumper systems. The tests are a quasi-static replication of real world low speed collisions. The tests represented front to rear impacts between various vehicles. Force and deflection were captured in order to quantify the stiffness characteristics of the bumper-to-bumper system. A specialized test apparatus was constructed to position and load bumper systems into each other. The purpose was to replicate or exceed damage that occurred in actual collisions. The fixture is capable of positioning the bumpers in various orientations and generates forces up to 50 kips. Various bumper-to-bumper alignments were tested including full overlap, lateral offset, and override/underride configurations.

There is a paucity of recent data quantifying the injury risk of forces and accelerations that act on the whole body in a back-to-front direction. The purpose of this study was to quantify the level of back-to-front accelerations that volunteers felt were tolerable and non-injurious. Instrumented volunteers were dropped supine onto a mattress, and their accelerations during the impact with the mattress were measured. Accelerometers were located on the head, upper thoracic and lower lumbar regions. Drop heights started at 0.6 m (2 ft) and progressed upward as high as 1.8 m (6 ft) based on the test subjects' consent. The test panel was comprised of male and female subjects whose ages ranged from 25 to 63 years of age and whose masses ranged from 62 to 130 kg (136 to 286 lb). Peak head, upper thoracic and lower lumbar accelerations of 25.9 g, 29.4 g and 39.6 g were measured.

It has been proposed that low speed collisions in which the damage is isolated to the bumper systems can be reconstructed using data from customized quasistatic testing of the bumper systems of the involved vehicles. In this study, 10 quasistatic bumper tests were conducted on 7 vehicle pairs involved in front-to-rear collisions. The data from the quasistatic bumper tests were used to predict peak bumper force, vehicle accelerations, velocity changes, dynamic combined crush, restitution, and crash pulse time for a given impact velocity. These predictions were compared to the results measured by vehicle accelerometers in 12 dynamic crash tests at impact velocities of 2 - 10 mph. The average differences between the predictions using the quasistatic bumper data and the dynamic crash test accelerometer data were within 5% for bumper force, peak acceleration, and velocity change, indicating that the quasistatic bumper testing method had no systematic bias compared to dynamic crash testing.

Performing a reconstruction of sideswipe interactions is difficult due to the lack of permanent crush sustained by the vehicles involved. Previous studies have provided insight into the forces involved in creating various types of damage for vehicle-to-vehicle interactions during a sideswipe interaction. However, these data may not be applicable to the interaction that occurs when a tractor-trailer steer tire is involved. As demonstrated in previous studies, steer tire interaction produces a unique pattern of markings on the struck vehicle by the protruding lugs (wheel stud) of the steer tire. These studies have demonstrated that the pattern of cycloidal marks created by the wheel lugs can be used to calculate the relative speeds of the vehicles. While this is helpful in understanding the relative motion of the vehicles, it does not provide information regarding the forces applied at the point of contact.