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of Engineering, United States

Truong Q.-T.,Laboratory of Applied Mechanics | Argyoganendro B.W.,Konkuk University | Park H.C.,Konkuk University
Journal of Bionic Engineering | Year: 2014

In this work, we develop an artificial foldable wing that mimics the hind wing of a beetle (Allomyrina dichotoma). In real flight, the beetle unfolds forewings and hind wings, and maintains the unfolded configuration unless it is exhausted. The artificial wing has to be able to maintain a fully unfolded configuration while flapping at a desirable flapping frequency. The artificial foldable hind wing developed in this work is based on two four-bar linkages which adapt the behaviors of the beetle's hind wing. The four-bar-linkages are designed to mimic rotational motion of the wing base and the vein folding/unfolding motion of the beetle's hind wing. The behavior of the artificial wings, which are installed in a flapping-wing system, is observed using a high-speed camera. The observation shows that the wing could maintain a fully unfolded configuration during flapping motion. A series of thrust measurements are also conducted to estimate the force generated by the flapping-wing system with foldable artificial wings. Although the artificial foldable wings give added burden to the flapping-wing system because of its weight, the thrust measurement results show that the flapping-wing system could still generate reasonable thrust. © 2014 Jilin University.

Ruan J.,Tsinghua University | Ruan J.,Laboratory of Applied Mechanics | Feng X.,Tsinghua University | Feng X.,Laboratory of Applied Mechanics | And 5 more authors.
AIAA Journal | Year: 2010

In this work the dynamic thermoelastic response of a slab with finite thickness subjected to aerodynamic heating is investigated. The system of generalized governing equations with generalized initial and boundary conditions is solved by the method of finite integral transformation, and the analytic expressions of the transient temperature and dynamical stresses in the slab are obtained. The finite integral transformation method shows its advantage and convenience to deal with the complex boundary conditions of a dynamic thermoelastic problem. Moreover, by introducing the aerodynamic heating and taking into account a typical Mach number curve for hypersonic flight, the analytical solution is obtained to simulate the dynamic thermoelastic response of the slab in hypersonic flight environment. Calculations are carried out for zirconium diboride to obtain transient temperature and dynamical stresses induced by aerodynamic heating. Copyright © 2010 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

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