1. Deployable Space Structures
The fiber-reinforced shape memory polymer composite (SMPC) is naturally considered to be manufactured with the characteristics of low density, low cost, high reversible strain, high strength, high modulus, high stiffness, good resistance against creep, and relatively high recovery stress. So, the SMPC has good control of deployment of the space structure, reduces the complexity of the space structure, and improves the stability of the deployment.
(a) A solar panel was deployed actuated by actuated SMPC hinge under the simulated ground-based weightlessness conditions. Compared to the traditional metal twist spring type hinge drives and motor type mechanical control launch devices, SMPC hinge driving device has numerous advantages including: simple structure, light, easy supervision and control, facilitates repeat process, and design flexibility.
(b) The local post-buckling theory is required for the unidirectional fiber reinforced composite materials at the conditions of its large geometrical deflection. On this basis, the analysis of buckling deformation for SMPC was proposed.
Fig.1 The in-plane deformation of SMP composite
Fig.2 The snap-shot images during the deployment of hinge
Fig.3 A deployment process of a prototype of solar arrays which is actuated by a SMPChinge
2. Morphing Structures
Morphing technologies will enable aircraft to be more efficient and operate under a wide range of varying flight conditions. It will be used to improve aircraft performance, expand its flight envelope, replace conventional control surfaces, and reduce drag to improve range which provides the ability to maximize the performance of each mission envelope. The morphing concept changes shape dramatically via a morphing wing such as a folding a sliding, or a variable camber wing.
Now, our group focuses on the three aspects in morphing structures namely:
(a) Morphing skins, which are not only enable transformable but also support aerodynamic loads
(b) Smart actuators, which show good performances in lightweight and high-output
(c) Adaptive structures, which could change the parameters of wing area, backswept, aspect ratio, twisting, wing camber, etc. with the different flight conditions.
Fig.4 Variable camber wing based on Shape Memory Polymer skin
Fig.5 The active morphing skin based on Pneumatic Muscle Fibers actuate the variable camber wing at different actuation pressures
Fig.6 Honeycomb structures experimental setup: (a) flatwise compression tests; (b) three-point bending tests; (c) and (d) tensile tests.
