An experimental analysis of component contributions to shock absorption performance in third generation sport artificial turf

Abstract

The increasing use of artificial turf across all levels of sports play has been hypothesized to contribute to an increase in athlete injuries. Current testing standards evaluate the shock absorbing performance of artificial turf surfaces through a single measure of acceleration after a drop test impact. However, these standards focus on the performance of the aggregate turf system, thereby neglecting the component-level contributions of the shock pad, carpet, and infill constituents. The purpose of this study was to explore a novel testing methodology that has the potential to isolate first-order and second-order contributions of components to total system performance. Various subsystems of the traditional, three layer artificial turf were treated as energy absorbing surfaces. A series of no-fatigue and fatigue tests were performed using a custom-built apparatus to characterize each energy absorbing surface at five different drop heights. During no-fatigue testing, it was found that the complete three-layer system outperformed all subsystems by mitigating resultant acceleration and force compared to the baseline. However, any energy absorbing subsystem that contained rubber infill outperformed any subsystem that included shock pad, the designated energy dissipating layer in third generation artificial turf. For fatigue testing, it was observed that energy absorbing surfaces began to deteriorate in as few as 20 impacts. In comparison to existing standards, the inclusion of a second data acquisition instrument yielded more accurate calculations of shock absorption. By capturing an input and output measurement during the impact, calculation of the surface’s characteristic transfer function is attainable and therefore, more information in gleaned from the impact test. Additional research is required to be able to deploy this testing methodology on-site, with fully installed artificial turf systems.