Morphing structure

• Main Author: Tian, Pei Lin.
• Other Authors: Chen Yan
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Mechanical engineering::Machine design and construction
• Online Access: http://hdl.handle.net/10356/40398
• Institution: Nanyang Technological University

Morphing structure has been given great interest because of its ability of changing their geometric shape and subsequently the application function. For the design of morphing structures, overconstrained linkages have been used as the key construct element due the single internal degree of freedom. This report focuses on the application of two types of over-constrained linkages, Bennett linkage and Sarrus linkage. The first part of this report focuses on the construction of deployable structures using Bennett linkage as the basic unit. A family of foldable shelters has been designed. The frame of the shelter is an assembly of five Bennett linkages. In order to get a compact folding while keeping the large interior space for deployed shelter, the alternative form of the linkages has been used. The assembly has only one degree of mobility, which is used for the deployment and folding of the shelter. The shelter has only two kinds of components, the joints and bars. By changing the length of the bars, the size of the shelter can be modified easily, which makes the proposed design have wide applications. The second part presents a design of morphing wing mechanism using Sarrus linkage. This project is focused on a conceptual design stage. A number of design ideas have been explored, which includes the single Sarrus linkage design, 8R linkage design and multiple Sarrus linkage in series design. The prototype of the first design is also built up and tested in real flight to show the feasibility of our design successfully. The latter two design ideas are to achieve the higher retractable ratio. The actuation is also explained in the report. More work on the expandable membrane for the morphing wings and the aerodynamic analysis shall be carried out to accomplish the design. The research work reported here could serve as inspirations for future studies on applications of overconstrained linkages and lead to substantial advancement in modeling large scale morphing structures.