Quantifying the Uncertainty in the Coefficient of Restitution Obtained with Accelerometer Data from a Crash Test

This paper details a method for obtaining the coefficient of restitution from a vehicle-to-vehicle crash test and for quantifying the uncertainty in the resulting value. The coefficient of restitution is determined by analyzing accelerometer data to obtain the post-impact velocity conditions for the test and, by then, using the method of least squares to fit an impulse-momentum solution to the results of the accelerometer data analysis.

Uncertainties that affect the accelerometer data analysis include uncertainties associated with the acceleration readings and the accelerometer locations within the vehicle-fixed coordinate system. Uncertainties that affect the fit between the impulse-momentum solution and the post-impact velocity conditions include uncertainty associated with the vehicle weights and moments of inertia and uncertainty associated with the placement of the impact center. Also, since uncertainties in the accelerometer data analysis result in a range of values for the post-impact velocity conditions, there is a range of possible matches between the accelerometer data analysis and the impulse-momentum equations.

This paper presents a case study for which the combined effects of uncertainty from the accelerometer data analysis and the fitting of this analysis with an impulse-momentum solution are quantified. A general method is presented for quantifying the uncertainty in the analysis of the coefficient of restitution for any particular crash test.