Vehicle Speed Change and Acceleration Associated with Curb Impacts and a Comparison to Computer Simulation with a Multi-Point Radial Spring Tire Model 2008-01-0158

This paper is a follow up to a study published in 2005 ¹ on the same topic and presents a study that was conducted to compare vehicle speed change and acceleration data from full-scale testing to results generated by computer simulation using the SImulation MOdel Non-linear (SIMON) vehicle dynamic simulation model version 3.1 within the Human Vehicle Environment (HVE) software version 5.2. SIMON will be referred to in this paper as the computer or simulation model, while HVE will be referred to as the computer software. In the previous study, a simple method to model the curb was developed and version 2.0 of the simulation model was validated, for delta-v, up to approximately 6.7 m/s (15 mph) and for vertical accelerations, up to speeds of approximately 4.5 m/s (10 mph).

The impetus for this follow-up paper originates with the release of a significantly different physics package for an additional tire model option within the referenced simulation model, including the radial spring, soft soil and sidewall impact models. The study seeks to determine if the tire model modifications in version 3.1 compensate for the limitations encountered in version 2.0, especially at higher speeds and angles with significant departure from perpendicular to the curb. The results of the full scale testing of a full-size pickup truck are reanalyzed and expanded, in this paper, for higher test speeds. In addition, the study is supplemented with full-scale testing of a passenger automobile. Instrumented tests were performed at approach angles of 90° and 45°. The computer model was then used to simulate and compare to the full-scale testing conducted by the authors.

The simulation results, including primarily vehicle speed change and accelerations, are compared to the results of full-scale testing for both vehicles and both approach angles. The appropriate method for modeling curb profile within this new version of the simulation model is compared to the previous method. Finally, a comparison between available published literature and the actual test results from this study is also updated in this paper.