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柔性蒙皮是变形机翼和风力机叶片的关键组成部分。一维变形的柔性蒙皮不仅要求其支撑结构具有良好的面内变形和面外承载能力,还需要具有零泊松比特性。手风琴蜂窝具有零泊松比特性,可用作一维变形柔性蒙皮支撑。为全面分析其面内外弹性变形特性,综合考虑结构的内力弯矩、轴力和剪力,通过卡氏第二定理对其x向等效弹性模量和x-y面内等效剪切模量进行了推导;利用最小余能原理和最小势能原理确定了x-z面内的等效剪切模量;此外还推导了其y和z向的等效弹性模量以及y-z面内的等效剪切模量;然后通过ANSYS有限元仿真对等效模量理论公式进行了验证;最后将本文理论模型与现有模型进行了比较。结果表明,理论公式和有限元仿真吻合较好,在结构设计时采用较大的斜梁高度系数h和斜梁间距系数g,较小的厚度系数t以及较大的竖直梁厚度系数η,有望获得具有较小面内刚度和较大面外刚度的手风琴蜂窝结构。该结果可用于手风琴蜂窝面内外等效模量的快速预测,为一维变形柔性蒙皮的结构设计提供相应的参考。此外,本文理论模型相比传统模型更为精确且具有更加广泛的应用范围。
Flexible skin is a key component of deformed wings and wind turbine blades. One-dimensional deformation of the flexible skin requires not only its support structure has good in-plane deformation and out-of-plane bearing capacity, but also need to have zero Poisson’s ratio. Accordion honeycombs have a Poisson’s ratio of zero and can be used as a one-dimensional textured flexible skin support. In order to comprehensively analyze the in-plane and out-of-plane elastic deformation characteristics, considering the internal moment, the axial force and the shear force of the structure, the equivalent X-ray elastic modulus and the equivalent shear modulus in the xy plane The equivalent shear modulus in the xz plane was determined by the principle of the minimum residual energy and the minimum potential energy. The equivalent elastic modulus in the y and z directions and the equivalent shear mode in the yz plane The ANSYS finite element simulation is then used to verify the equivalent modulus theory formula. Finally, the theoretical model of this paper is compared with the existing model. The results show that the theoretical formula is in good agreement with the finite element simulation. In the structural design, the larger slant beam height coefficient h, the slant beam spacing coefficient g, the smaller thickness coefficient t and the larger vertical beam thickness coefficient η are adopted. It is expected that accordion honeycomb structures with smaller in-plane stiffness and greater out-of-plane stiffness will be obtained. The results can be used for the rapid prediction of the equivalent modulus inside and outside the accordion honeycomb and provide reference for the structural design of one-dimensional deformed flexible skin. In addition, the theoretical model of this paper is more accurate and has a wider range of applications than the traditional model.