Evaluation of cushioning property of long pile synthetic turf considering landing impact in running

Abstract

In this research, we aim to evaluate the cushioning property of long pile synthetic turf by modelling and computer simulation. Experimental equipment was developed for multi-intensity and multi-area impact tests with various drop weight ranged from 5 kg to 60 kg. And impact tests with drop height ranged from 15 mm to 75 mm, four different impact areas and 60 kg drop weight were performed to three specimens which have different hardness controlled by the ratio of infill sand and rubber chip. Additionally, we adopted the rounded bottom impact test foot for improving the identification accuracy of the model by reducing the data variation in the same condition. From the experimental results, we proposed an exponential nonlinear Voigt model for representing the dynamic behavior of the long pile synthetic turf and calculated the parameters for each specimen. As a result of identification, the average RSE (relative standard error) of each specimen were about 13% to 15% and it seems that the identification accuracies were relatively high compare to the previous studies. In addition, the buffering performance was evaluated by simulation of various conditions assuming the landing impact during running. As a result, it became clear that the FR values decrease with increasing the impact time in every specimen.