Design sensitivity analysis of static aeroelastic stresses constitutes an important issue for the gradient-based integrated design optimization of wing structure, and can be analytically performed using a new modified stiffness matrix. However, introducing a modified stiffness matrix into the calculation will give rise to additional computational effort. Additionally, the direct method is incompetent for the problem containing a large number of design variables. In this research, a novel iterative adjoint-based method is presented for stress sensitivity analysis of flexible wing, the basis of which lies in the coupling between aerodynamic potential-flow panel model and structural finite element (FE) model. By virtue of an iterative approach for evaluating adjoint variable, we can obviate the modification to original stiffness matrix. Moreover, the adjoint-based method is more superior to the direct method when there are a large number of design variables. To demonstrate the verification of the algorithms, a rectangular wing, a swept wing and a large-scale unmanned aerial vehicle (UAV) are employed as numerical examples, and the design sensitivities of element equivalent stresses are calculated and analyzed.

静态气动弹性应力的设计灵敏度分析是基于梯度的机翼结构集成设计优化的一个重要问题，可以使用新的修正刚度矩阵进行分析。然而，在计算中引入修改后的刚度矩阵会增加额外的计算量。此外，直接方法无法解决包含大量设计变量的问题。在这项研究中，提出了一种新的基于迭代伴随的柔性翼应力敏感性分析方法，其基础在于气动势流板模型和结构有限元（FE）模型之间的耦合。凭借评估伴随变量的迭代方法，我们可以避免对原始刚度矩阵的修改。而且，当存在大量设计变量时，基于伴随的方法比直接方法更优越。为了验证算法的有效性，以矩形翼、后掠翼和大型无人机（UAV）为例，计算分析了单元等效应力的设计灵敏度。