Abstract
Today, Nickel-Titanium (NiTi)-based shape memory alloy (SMA) wires are already used in a wide range of commercial actuator applications. The combination of their unique properties, such as their high energy density as well as their biocompatibility provides a broad range of applications. The former in particular allows for designing light-weight actuator systems with high forces using small installation spaces. In systems like emergency brakes or switch disconnectors, which require high forces as well as high actuation speed, the high-power capability of NiTi actuators is exploited. The presented work discusses the development of a giant power catapult demonstrator, that combines the high-speed and high-force capability of SMA wires.
To illustrate the vast force, speed, and power potential of SMA wires, a bowling ball is launched from its resting position into the air using SMA wire bundles. For demonstration purposes a target altitude for the bowling ball of 500 mm is chosen, requiring a theoretical actuation force of F ≅ 920 N. To be able to launch the bowling ball to the desired height, an instantaneous energy release with an overall peak-power of P ≅ 0.5 MW is required.
