Morphing structures

• Main Author: Tan, Sharon Si Ying.
• Other Authors: Chen Yan
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Functional and smart materials
• Online Access: http://hdl.handle.net/10356/16119
• Institution: Nanyang Technological University

This project aims to investigate specific applications of smart materials in the design of a morphing wing. Smart materials have great potential in many fields, and are already widely used in some fields. This report will focus on application of smart materials, namely Smart Memory Polymer (SMP) and Smart Memory Alloy (SMA) in the area of morphing wings. In this report, there will be four distinct designs that make use of smart materials in different ways to create geometric changes to a wing. The feasibility of each design will also be analyzed and conclusions will be drawn. First, SMP was used in the actuation of a small curved winglet. This design only provides for one-way actuation and demonstrations show that it is a feasible design, allowing initial winglet tip deflections of 45 °. However, during the course of this project, there was a lack of appropriate materials to allow for Joule heating of the SMP. Further studies can be done on the use of conductive SMP for this design. Second, SMA was used to actuate a hinged winglet. In this design, SMA was required to produce a torque that will rotate the winglet between two positions: upright and flat. This is a two-way actuation and the demonstrations proved that this was a feasible design, with a deflection of approximately 42.7 °. In the third and fourth design, SMA wires were embedded in silicone. The silicone is intended as a bias force to mimic two-way actuation. Demonstration results showed otherwise. The design was only one-way, in that the silicone was not strong enough to pull the SMA into its martensite shape after cooling down from its austenite state. In future studies, a stronger elastomer can be used to increase the strength of the bias force. In summary, the first two designs have proved to be conceptually feasible, with improvements due in future studies. The third and fourth design may need further research to enable it to be a two-way actuation. In this report, it only managed to be a one-way actuation.