Abstract
Frontal collisions involving motorcycles often results in tire damage, wheel deformation and/or fracture, and deformation to the fork tubes and to the frame. Forensic engineers and vehicle safety researchers continue to seek correlation between the extent of this damage and motorcycle collision impact speeds. Many full-scale motorcycle crash tests have been performed and linear regression relationships between wheelbase reduction and impact speed have been developed with some success. The current methodology neglects the deformation or “crush” damage to the motorcycle front wheel. Modern motorcycle wheels are either light cast aluminum alloy or heavier ductile steel rim-and-spoke construction. In both cases, the motorcycle wheel is a significant load-bearing component of the motorcycle construction and the various material properties and geometry are expected to contribute the energy dissipated during deformation. This research hypothesizes that the energy dissipated by the motorcycle front wheel damage is non-trivial and further seeks to develop a methodology through which the damage energy can be quantified and used to augment existing models and improve the fidelity of collision speed prediction based on motorcycle damage. Finite element analysis of a cast aluminum alloy and a steel spoke rims is performed and load-deflection and stress-strain relationships are developed and utilized to quantify the energy dissipated during the deformation of these two most common motorcycle wheel constructions. The results are used refine speed analysis performed following instrumented full-scale motorcycle crash tests and provide a standardized method for measuring the post-collision deformation of motorcycle wheel rims. This research is computer simulation based; however, the methodologies can be extended to laboratory compression testing of similar motorcycle wheels to verify the simulation results.