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Fusheng Wang Shihui Huo Shengjun Qiao Junran Zhang Zhufeng Yue 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(1):58-76
Static aeroelastic and flutter characteristics of an aircraft composite wing with high aspect ratio were analysed by an effective Computational Fluid Dynamics and Computational Structure Dynamics coupled method. Effects of stiffness distribution on aeroelastic characteristics were considered. Honeycomb core sandwich composite was considered to be equivalent to an orthotropic material by stiffness and inertance equivalent method to allow highly efficient numerical simulation, which was used for analysis of bending and torsional stiffness distribution. The results showed that the redistributed aerodynamic load leads to a decrease of pressure difference between the upper and lower airfoils. The flutter speed of the composite wing is near 0.64 Ma. Both bending and torsional stiffness increases with a small increase of beam size. Stiffness of the wing root has a major influence generally on the static aeroelastic characteristics. Both the lift coefficient and the loss percent decrease with a small increase of beam size. Effects of stiffness distribution on frequency are not obvious. Flutter speed remains close to the initial value when the beam size is changed. 相似文献
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A redox-induced radical Ru(bpy)(3)(2+)-(CH(2))(n)-MV(+)˙ (n = 4, 7) and its dimerization in cucurbit[8]uril (CB[8]) have been observed concomitantly in aqueous solution, which depends heavily on the length of the carbon chain linkage, in the case of n = 4, the characteristic pattern for the radical dimer is predominating, while that for the radical becomes dominated for n = 7. 相似文献
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This paper studies the relationship between the so-called bi-quadratic optimization problem and its semidefinite programming
(SDP) relaxation. It is shown that each r-bound approximation solution of the relaxed bi-linear SDP can be used to generate in randomized polynomial time an O(r){\mathcal{O}(r)}-approximation solution of the original bi-quadratic optimization problem, where the constant in O(r){\mathcal{O}(r)} does not involve the dimension of variables and the data of problems. For special cases of maximization model, we provide
an approximation algorithm for the considered problems. 相似文献