EFFECTIVENESS OF SHAPE MEMORY ALLOY GOLF CLUBS IN ENHANCING GOLFER PERFORMANCE

Many scientific developments pioneered by governmental research organizations are subsequently applied to consumer products. The use of shape memory alloys (SMAs) by NASA at the end of the 20th century motivated companies to incorporate these materials and their unique properties into marketable goods. In 1997, NASA reported that the Nicklaus Golf Company had developed a line of SMA-augmented golf clubs; the company claimed that its SMA club inserts reduced vibration and imparted greater spin on balls during contact. Inspired by these claims of enhanced performance, this work investigates the impact of SMA clubfaces on golf ball carry distance and shot accuracy for several clubface contact locations and slice angles. For each combination of shot parameters tested, the ball exit velocity and spin were computed via finite element analysis (FEA) using an explicit dynamic model that accounts for stress-induced phase transformation in SMA material regions and golf ball responses calibrated from experimental testing. The exit velocity and spin rate were used to calculate the ball flight trajectories for each case simulated. Alloy and design assumptions, including the addition of an internal cavity, were made to facilitate the development of stresses necessary for meaningful SMA material responses during clubfaceball impacts. These assumptions lead to findings such as nearly equivalent performances for geometrically identical clubheads with steel and SMA clubface inserts. Overall, this work shows that the use of reasonable SMA materials in a clubhead operating under normal weather conditions is inconsequential to shot accuracy and carry distance.