Vehicle accidents in which the automobile “rolls over” or overturns are among the most difficult accidents to reconstruct. Vehicles typically overturn about their longitudinal axis and in highway speed rollovers can overturn multiple complete revolutions. The accident reconstruction specialist is left to piece together the incident from physical evidence produced both on the vehicle and at the accident site. A number of works have been published by various authors detailing the methods for calculating many aspects of the accident. Using these methods the reconstruction professional is obliged to illustrate and present the accident using two-dimensional or threedimensional drawings to illustrate the accident. One can also use such a diagram to produce an animation of the accident. These animations are based on one’s own conceptualization of the accident as physical evidence reveals, but they are not the result of the extensive time step calculations of vehicle dynamics that can be done with computer reconstruction software.
As the computer has become more powerful and faster, physics based modeling programs have been developed to aid the reconstruction professional with the analysis of automobile accidents. For the most part, accident reconstruction software packages do not contain detailed component/suspension modeling capability. However, for the purposes of accident reconstruction, the models in these software packages are more than sufficient to model an accident scenario such as a vehicle tumbling or rolling over.
In this paper, a reconstruction of a staged rollover accident involving an SUV type vehicle will be presented. The subject rollover is a staged un-tripped rollover. The test vehicle overturns because of frictional forces at the tires imparted by steering inputs. This rollover is modeled using PC Crash™. The test site was well documented after the event and pertinent physical data was recorded. Damage produced on the vehicle as a result of the rollover is also well documented. Numerous video cameras were used to record the rollover from a variety of vantage points. All of this information is used in conjunction with the software to demonstrate how properly used software can effectively model a rollover accident. If rollover accidents can be accurately modeled, then the data may be used in developing vehicle safety and occupant protection systems.