High-Power and High-Speed SMA Bowling Ball Demonstrator

Abstract:
The high energy density of Nitinol-based shape memory alloys (SMA) wires is already often used in industrial actuator applications, most commonly as a replacement for heavy and space consuming conservative components. Until now they are not used to their full extent and primarily serve as low- to mid-power actuators. This paper discusses the high-power and high-speed potential of SMA-based actuators. Furthermore, the designed and engineered demonstrator shows the huge capability of the material. For illustration of the force and power potential, a bowling ball is launched from its resting position into the air only using Nitinol wires. For illustration reasons a target altitude for the bowling ball of 500 mm is picked. That height given; the necessary kinematic momentum needed to be executed from the expected 4% strain of the used SMA wires generating the needed launch velocity v =~ 3,13 m/s. In consideration of the known material parameters of Nitinol and the prior mentioned kinematic values, an activation energy of at least W =~ 360 J is needed, which is supplied by special designed power circuit boards. After the system validation, the demonstrator is put into operation resulting in reaching the area of the targeted height while a system peak-power of P =~ 0,5 MW is measured.