节点文献
用于变体机翼的大变形柔性蒙皮构型及性能的初步探究
Preliminary Inquiry into Configuration and Performance of Large Deformation Flexible Skin for Morphing Wing
【作者】 牟常伟;
【导师】 王帮峰;
【作者基本信息】 南京航空航天大学 , 测试计量技术及仪器, 2010, 硕士
【摘要】 变体机翼成为未来先进飞行器的发展方向之一。变体机翼为了实现光滑大变形以及承受较大的气动载荷,要求机翼蒙皮沿变形方向有较大柔度,在垂直变形方向有较强的抗弯刚度。波纹结构在沿波纹方向(纵向)有较大柔度,在垂直于波纹方向(横向)有较大的抗弯刚度,因此,可以作为变体机翼蒙皮的一种候选结构。本文的研究重点是波纹式纤维增强复合材料蒙皮,另外对蜂窝柔性蒙皮构型进行了初步探究。为研究波纹蒙皮特性,提出了波纹蒙皮基体的纵向拉伸及横向弯曲承载分析模型,得到了纵向伸长量及横向抗弯刚度的计算式。制作了纤维增强复合材料波纹蒙皮基体试件,通过实验测试证明了理论计算模型的正确性。在此基础上,对波纹结构参数进行了优化,优化件测试结果表明:优化后的波纹蒙皮基体纵向拉伸性能得到了显著地提高,且保持了较强的横向承载能力。为使蒙皮具有主动变形能力,设计制作了将形状记忆合金(SMA)作为驱动器埋入蒙皮内部的装置,并用该装置制作了试件。驱动实验显示:弹性变形范围内,可利用蒙皮自身弹性使蒙皮回复为原来形状;用热电片对SMA制冷后,蒙皮回复速度有了明显提高。此外,本文开发了红外测温系统,用于实时监测SMA及蒙皮表面温度,保证蒙皮稳定、正常工作,为蒙皮的变形控制提供了研究基础。最后,对蜂窝式柔性蒙皮进行了初步探究,推导了基于Y模型的蜂窝胞元在单向应力下x、y方向的等效弹性模量,并对蜂窝测试件进行了拉伸测试。
【Abstract】 One of development directions of future aircrafts is morphing wing.Flexible in deformation direction and stiff in the direction perpendicular to the deformation direction are essential to get smooth large deformation and withstanding large aerodynamic loads. Corrugated-form is very flexible in the corrugation (longitudinal) direction and show enough resistance against bending loads in the direction (transverse) perpendicular to the corrugation. So, corrugated-form is expected to be a candidate to develop skin of morphing wings. In this investigation, research focus was put on the corrugated-form composites. On the other hand, honeycomb core flexible skin was preliminary inquiry.Calculation models of corrugated basal body were proposed to analysis the longitudinal tensile deformation characteristics and bending lateral bearing characteristics. The formulas of longitudinal extension length and transversal flexural rigidity were calculated. Corrugated skin specimens reinforced by composite were made and experimental tests were done to prove the correctness of calculation models. On this basis, optimization work of corrugated skin specimens was carried out. The experimental results of optimal specimens indicated that longitudinal tensile deformation characteristics of optimal specimens were significantly increased and enough resistance against bending loads in transverse direction was inherited.A debice was designed and made to embed shape memory alloy (SMA) actuator in corrugated skin specimens to make skin posses active deformation ability. Specimens were made and driving experiment showed that skin can self-actuated revert because of the elasticity in elastic range. The velocity of shape recovery of skin was accelerated afer using thermoelectric chips. What is more, infrared temperature measurement system was developed to monitor the temperature variation of SMA and skin real-timely to ensure the stable and normal performance of the skins. And the development of infrared temperature measurement system provided the research foundation for deformation control system.Finally, cellular flexible skin was studied simply. Equivalent elastic modulus of x and y directions were deduced based onY model cellular unit in uniaxial stress. And tensile testing of specimens of cellular structure was performed.
【Key words】 ★morphing wing; corrugated skin; calculation mode; SMA; infrared temperature measurement; honeycomb structure;