Vibration Transmission in the Hand and Arm from Composite Driveline Components for Impact Tools

A multi-year study was initiated to evaluate the performance of conventional impact tools and develop improved designs that reduce vibration and sound emission. The initial focus was to improve hand struck and power tool designs using reinforced engineering polymers between metal impacting components. Non-linear models describing the equations of motion and resulting output forces were developed. In addition, several experiments with a high frequency Instron test machine and prototype tools were performed to validate the model and compare performance of conventional power tools to the new polymer based designs. The results show that although adding a polymer does significantly reduce vibration, the change in cutting (output) force is relatively small and statistically insignificant. Thus far, polymers with mineral reinforcements demonstrate higher effective stiffness and durability compared to fiber reinforced composites.