Friedman K.,Friedman Research Corporation |
Hutchinson J.,Friedman Research Corporation |
Mihora D.,Friedman Research Corporation |
Cummings J.,Cummings Scientific LLC
International Journal of Crashworthiness | Year: 2015
Rollover fatalities and serious injuries represent a large portion of the harm occurring in traffic crashes in the United States. Restrained occupants whose heads are reported partially ejected have a much worse outcome than those whose heads are not partially ejected. Prevention of partial ejection represents a significant objective in automotive design. In this study, two methods are investigated involving an empirical methodology and a finite-element-model methodology. A finite-element model of a production vehicle is utilised under rollover impact conditions in conjunction with a restrained occupant characterised by a Hybrid III dummy. The properties of the model are compared with human volunteer characteristics in the production vehicle. The restrained occupant model is then utilised under rollover impact conditions with the baseline production vehicle and modified versions of the roof structure. Comparison of the results associated with the empirical method and finite-element method is provided as are the results of the effects of the modified roof structure on partial ejection. © 2015 Friedman Research Corporation.
Osterholt G.,Cummings Scientific LLC |
Cummings J.,Cummings Scientific LLC |
Biller B.,Cummings Scientific LLC |
Calhoun V.,Cummings Scientific LLC
SAE Technical Papers | Year: 2010
Often, the accident reconstructionist will find that there is no crash test data for a particular vehicle, making a direct calculation of the crush stiffness coefficients impossible without performing an actual crash test. A faster and more cost effective solution is to use "generic" crush stiffness coefficients that relate similar already tested vehicles to the incident vehicle. One previously published article that has been used for this purpose is; "Updating the Vehicle Class Categories" by Siddall and Day [ 9 ]. However, this paper, along with Hargens and Day's earlier paper, "Vehicle Data Sources for Accident Reconstruction" [ 3 ], are now somewhat outdated by newer model vehicles. New generic crush stiffness coefficient values were calculated to better represent newer vehicles produced between 1990-1999 and 2000-2009. The same eleven vehicle classifications used in this article were obtained from the above cited paper. The crush stiffness coefficients were calculated for each category for the entire population of the data used. The data was broken into different decades in which the vehicles were produced. After the analysis was performed, it was noted that crush stiffness values showed an upward trend for newer vehicles. Copyright © 2010 SAE International.