Mechanical instabilities and elastic nonlinearities are emerging means for designing deployable and shape adaptive structures. Dynamic snap-through buckling is investigated here as a means to tailor the deployment and retraction of a slat-cove filler (SCF), a morphing component used to reduce airframe noise. Upon deployment, leading-edge slats create a cove between themselves and the main wing, producing unsteady flow features that are a significant source of airframe noise. A SCF is designed here to autonomously snap out as the slat deploys, providing a smoother aerodynamic profile that reduces flow unsteadiness. The nonlinear structural behavior of the SCF is studied, and then tailored, to achieve a desirable snapping response. Three SCF configurations are considered: 1) a constant thickness (monolithic) superelastic shape-memory alloy (SMA) SCF, 2) a variable-thickness SMA SCF, and 3) a set of stiffness-tailored fiberglass composite SCFs. Results indicate that, although monolithic SMA SCFs provide a simple solution, thickness variations in both the SMA and stiffness-tailored composite SCF designs allow a decrease of the energy required for self-deployment and a reduction of the severity of the impact between the SCF and the slat during stowage. The enhanced nonlinear behavior from stiffness tailoring reduces peak material strains in comparison to previous SMA SCF designs that leveraged material superelasticity for shape adaptation. The stiffness tailoring is readily achieved through the use of layered composites, facilitating considerable weight savings compared to the dense SMA designs. The aeroelastic response of different SCFs is calculated using fluid/structure interaction analyses, and it is shown that both SMA and composite SCF designs can deploy and retract in full flow conditions.

机械不稳定性和弹性非线性是设计可展开和形状自适应结构的新兴手段。本文研究了动态快速屈曲，以此来调整板条形填充物（SCF）的展开和缩进，缝状填充物（SCF）是用于降低机身噪声的变形组件。部署后，前沿板条会在自身和主翼之间形成一个凹坑，产生不稳定的流动特征，这是机身噪声的重要来源。SCF在此设计为在板条展开时自动折断，从而提供更平滑的空气动力学轮廓，从而减少流动的不稳定性。研究SCF的非线性结构行为，然后进行调整，以实现理想的捕捉响应。考虑了三种SCF配置：1）恒定厚度（整体式）超弹性形状记忆合金（SMA）SCF，2）厚度可变的SMA SCF，以及3）刚度定制的玻璃纤维复合材料SCF。结果表明，尽管整体式SMA SCF提供了一种简单的解决方案，但SMA和刚度定制的复合SCF设计中的厚度变化都可以减少自部署所需的能量，并降低SCF和SCF之间的碰撞严重性。积载过程中的板条。与以前的SMA SCF设计相比，刚度剪裁增强了非线性性能，从而降低了峰值材料应变，而先前的SMA SCF设计利用材料的超弹性来适应形状。通过使用层状复合材料，可以轻松实现刚度定制，与致密SMA设计相比，可显着减轻重量。使用流体/结构相互作用分析来计算不同SCF的气动弹性响应，