模态选取对静气动弹性分析的影响

静气动弹性研究中关于结构的分析通常采用柔度法和模态法。相比技术成熟、计算量大的柔度法,模态法具有阶次低、求解快和便于试验验证的优点。但其作为近似的分析方法,在工程应用中需要一定的经验,尚缺乏模态选取的准则,该研究的目的是为模态法的工程应用提供模态选取的定量评价标准。针对某典型飞行器进行升降舵效率、副翼效率及气动导数弹性修正等分析,提出模态影响系数的概念来评估模态的选取对这些气动弹性分析的影响。结果表明,模态影响系数指标合理,能够反映模态选取对静气动弹性特性的影响,可以作为模态法中模态选取的定量评价指标。

Effect of modal selection on static aeroelastic analysis

The flexibility method and modal approach are usually used in structural analysis in the static aeroelastic research. Compared to the flexibility method which is mature but brings higher computational cost for the solution,the modal approach has the advantage of significant reduction in the dimension of the problem,high efficiency and convenient for verification. However, there are no principles for the selection of modes and one must have enough engineering experience to fully utilize the modal approach in practice. To provide modal approach with its own quantitative criteria in practice, this paper first proposes the idea of modal influence coefficient to evaluate the effect of modal selection on modal approach of aeroelastic analysis. In order to validate the rationality and validity of the modal influence coefficient, the paper carrys out control efficiency and aeroelastic correction analysis for a typical aircraft. The results show that the modal influence coefficient can accurately evaluate the effect of modal selection on static aeroelastic analysis, thus providing some helpful reference in practice.