复合材料翼面结构气动弹性剪裁

AEROELASTIC TAILORING OF COMPOSITE WING STRUCTURES

1.引言 本文采用了混合设计变量。对复材蒙皮,由于其连续性,我们用双三次多项式来描述各定向铺层的厚度,将多项式系数做为设计变量,对于其他部件如肋、腹板等,我们仍用其有限单元的截面积或厚度做为设计变量。整个结构采用有限元法做结构分析。固有振型采用高效率的谱变换Lanczos法计算,非定常气动力用亚音速偶极子格网法计算,用可行方向法求解优化问题。

This paper deals with aeroelastic tailoring of composite wing surfaces. The objective function is structural weight. Multi-constraints, such as displacements, flutter speed and gauge requirements, are taken into consideration. Finite element method is used to the static analysis. Natural vibration modes are obtained by the spectral transformation Lanczos method. SUM onic doublet lattice method is used to obtain the unsteady aerodynamics. The critical flutter speed is generated by V-g method. The optimal problem is solved by the feasible direction method. The thickness of tke composite wing skin is simulated by bi-cubic polynomials, whose coefficients and the cross-sectional areas or thicknesses of other finite elements are the design variables. The scale of the problem is reduced by variable linkage. Derivative analysis is performed analytically. One composite wing box and a sweptback composite wing are optimized at the end of the paper.