Experimental validation of a finite-element model of head-clamped tennis racket

Explicit finite-element models have previously been constructed and employed to better understand the game of tennis. In particular, work has involved simulating tennis balls impacting on a rigid surface and a string-bed. The purpose of this paper is to get a step further by experimentally validating an FE model of head-clamped tennis racket. This is the first stage on the creation and validation of a freely suspended tennis racket model. An FE model consisting of a tennis ball, string-bed and racket was constructed in Ansys/LS-DYNA 10.0 Impacts were simulated with an nominal ball inbound velocity of 20 m.s-1 and a nominal ball inbound angle of 40°. Four impact locations on the string-bed were analysed, with the backspin of the balls ranging from 0 to 600 rad.s-1. The FE model was found to be in a good agreement with laboratory-based experimental data for the full range of tested impacts. The results suggest that the tennis balls were over-spinning in the latter half of the impacts. It was also found that the rebound velocity of the balls decreased with increasing inbound backspin. This was concluded to be due to the frictional force acting between the ball and string-bed, increasing with inbound spin