FEA and experimental investigations of principal strains and contact times during impact of golf club head and ball

In order to widen a sweet area of a golf club head, it has been attempted to increase a coefficient of restitution in the peripheral portion of a face with a variable thickness distribution design. To do so, both the restitution and the strength performance are required, and technology for the estimation of the golf club head strength is necessary. In these investigations, principal strains of the face during the impact were compared between finite element analysis and experiments. As a result, following two conclusions were made. First, the finite element size of 0.4 mm is suitable to obtain the principal strains during the impact. Second, the sequential waveforms of the maximum principal strains show a similar tendency between analytical and experimental results. Also, following two points were considered. First, the magnitude of the principal strain of the face in the simulation was considered to show much better agreement with that of experiment when the contact times between simulation and experiment coincide with each other through the ball material modeling. Second, the bending of the face in the vertical direction was considered to be a major influential factor of the maximum principal strain.