Search Results

Tire failures, including tread belt detachments, have been associated with loss of control crashes including rollovers. Numerous reasons exist for control loss including forces created by the failed or failing tire, cornering capacity diminishment for the detreaded tire combined with control demands beyond the remaining capacity of the vehicle and inappropriate driver demands including excessive steering. Extensive studies have been completed to define the various causes of control loss and to identify risk-reducing countermeasures. These studies have included reconstructions of crashes and tests of real vehicles in test track environments with tires purposely caused to fail.

Understanding and measuring a vehicle's response to cyclical vertical inputs is fundamental to evaluating suspension tuning and handling characteristics. By using a frequency sweep with in-phase and out-of-phase decreasing displacements to the tires, the vehicle sprung and unsprung mass responses can be measured to quantify vertical accelerations across a frequency range. With these data, the resonant frequency characteristics of the front and rear suspensions can be determined. In addition, the acceleration gains of the unsprung mass and the vehicle body can be calculated. This evaluation is effective in identifying the similarities and differences in suspension response among various vehicles and in quantifying the changes of the response to various types of suspension tuning.

Reconstruction of motor vehicle collision crashes typically involves calculation of the change in velocity (Delta-V) of the crash-involved vehicle(s). Many scientific methodologies have been developed for such calculation and many of these require quantification of the damage sustained by the crash-involved vehicle(s) as a first step in that Delta-V calculation. Occasionally, this methodology is complicated when one or more of the crash vehicle(s) has been repaired or destroyed before the crush can be directly measured during a “hands on” physical inspection. In many instances, the only available documentation of the post-crash vehicle damage is a handful of photographs and/or videotape footage. The methodology detailed in this paper evaluates the accuracy and reliability of three-dimensional wireframe modeling techniques based on two-dimensional photographs to quantify the vehicle crush.