The study of coefficient of friction for light motorcycle sliding on asphalt road

摘要

The very high number of motorcycles in Taiwan contributes to its high accident rate. Handling a two-wheeled motorcycle during an accident is difficult, frequently resulting in falls and sliding along the road surface. Speed is often used to identify the party at fault. The friction coefficient and scrape mark length are typically used to estimate vehicle speed. Most literature focused on heavy motorcycles, and whether the friction coefficient is independent of speed. To resolve disputes about whether the friction coefficient is dependent upon speed, an accurate measurement methodology was applied to determine initial speed of a motorcycle sliding along a road surface. Experiments using 125cc scooters, that is, light motorcycles, were undertaken on dry and wet asphalt roads. Slide distance was measured to examine the relationship between a motorcycle’s scrape mark length and speed during slide tests. Experimental analysis showed that the square of speed is proportional to scrape mark length, and the linear relationship derived from the work-energy theorem indicates that the friction coefficient is independent of speed.