Bumper Paint Damage in Low Speed Impacts

This paper presents a methodology to determine the approximate closing speed of a striking vehicle and resultant delta-v of the struck vehicle in low speed collinear rear impacts through analysis of the paint damage pattern evident on the struck vehicle's rear bumper. This methodology is only applicable to collisions between vehicles that possess painted flexible plastic foam supported bumpers. Five impacts at each of 1.12 m/s, 1.79 m/s, and 2.69 m/s target speeds and three impacts at 3.58 m/s target speeds were conducted to provide the foundation for this methodology.

The use of powdered guidecoat is introduced to contrast the damage pattern on the bumper of the struck vehicle. A measurement of contact paint damage area is obtained and that damage area is then correlated to a closing velocity between the two vehicles. Measured coefficients of restitution and calculated quantities of energy absorbed are also presented for each impact.

The relationship between struck vehicle paint damage area and impact speed was found to be strongly statistically significant (p < 0.001). A positive correlation was found between struck vehicle bumper paint damage and struck vehicle delta-v, with an r-value of 0.978 at a statistically significant level (p < 0.001).