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One of the greatest challenges faced in the design of realistic occupant protection systems is an accurate statistical model of what is really needed. The paucity of data is this realm hinders designers of standards alike. Ideally, a model of crash statistics would correlate, for significant accident modes, injury level (as measured by AMA Abreviated Injury Scale “AIS”) with some adequate measure of crash intensity. Having this information, not only could the required level of safety design be ascertained, but also the justifiable economic expenditure could be estimated. This paper treats the statistical basis for deployment of a data retrival system. It provides a basis for estimates of the amount of data required, the number of vehicles to be instrumented, the crash severity trigger levels, and the economics of recorder installation, for various levels of injury and fatality.

This project covers one facet of a program to develop a mechanical model for characterizing the time history of local forces on the zygomatic, maxillary and mandible regions of the human face during a frontal collision. Two mechanical devices to measure the forces on crash dummies during testing were designed, constructed and tested. The devices employed cantilever beams equipped with strain gauges. Both devices were subjected to a series of drop tests onto various materials. Time histories were compared to those obtained from cadaver experiments. While the data obtained from this testing appears to be similar to the cadaver data, further improvements and modifications will make the model much more useful.

Snowmobile acceleration, braking and cornering performance data are not well developed for use in accident reconstruction. Linear acceleration and braking data published by D'Addario[1] gives results for testing on 4 snowmobiles of various make and model. This paper presents the results of on-snow tests performed in 2014 which include acceleration and cornering maneuvers that have not been published previously. Maximum and average cornering speeds and corresponding lateral accelerations are presented for turns of radius 20, 35 and 65 feet (6.1, 10.7 and 19.8 meters) on level, packed snow. Performance values for acceleration, braking, and cornering are determined in tests with and without a passenger. Results of linear acceleration and braking tests were found to be comparable to the previously published work. The data are useful in snowmobile accident reconstruction for certain types of snowmobile motion analyses.

Development of a seat with an active adjustable seatback stiffness for enhanced safety during a rear impact is demonstrated. Review of literature suggests that there is not a single value for seatback stiffness to optimize occupant protection. An automobile seat whose stiffness can be actively adjusted based on EDR input and other factors can potentially enhance occupant safety during some rear impact crashes. Static pull tests were performed using a prototype seat demonstrating how seatback stiffness can be modified, and deformation limited, using electromechanical means. Research and development of this technology is ongoing.

Gouges and scratches to rollover protection structures are informative to the reconstruction and analysis of real-world vehicle rollover crashes. Variations in ground surface composition can be correlated with accompanying witness marks on the vehicle rollover protection structure. This paper presents the results of rollover protection structure specimen tests using a variety of test speeds and surface compositions. The test results and analyses that follow are displayed for use in comparison to similar damage on subject crash vehicles. In addition, impact of steel rollover protection structures with various opposing ground surface materials can produce visible sparks in low light conditions. Tests were performed to show the ability of these structures to produce sparks from various surface impacts.