形状记忆合金驱动的可变翼梢小翼设计与验证

Design and Assessment of Variable Winglet Driven by Shape Memory Alloy

智能材料如形状记忆合金、压电材料、磁致伸缩材料等,可将驱动、承载、变形、传感集于一体,可作为驱动结构代替传统复杂作动机构,显著提高系统的紧凑性。为满足现有航空航天变体结构的实际需求,设计并验证了一种形状记忆合金(Shape memory alloy, SMA)驱动的可变翼梢小翼。基于开发的三维SMA本构模型,对SMA杆件驱动的翼梢小翼变形过程进行了数值仿真,并分析了不同SMA杆型对翼梢小翼变形能力的影响。结合增材制造技术,对设计出的变形翼梢小翼进行样机制作。进行了单次变弯、往复变弯试验验证,并与数值仿真结果进行分析对比。结果表明,试验测得变形数据和仿真结果吻合良好,设计出的变形翼梢小翼具有较好的变形能力和效果。最后分析了SMA杆冷却速度对变形能力的影响,评估了翼梢小翼变形过程中出现蒙皮屈曲的原因并提出了后续研究方案。

Intelligent materials such as shape memory alloy, piezoelectric material and magnetostriction material have the functions of driving, bearing, transshaping and sensing. They can take the place of traditional actuators to significantly improve the compactness of the system. In order to meet the actual needs of morphing aircrafts, a variable winglet driven by the shape memory alloy(SMA) is designed and assessed. Based on the developed three-dimensional SMA constitutive model, and simulated the deformation process of the variable winglet driven by SMA rods and analyzed the influence of different SMA rod types on the deformation ability of the winglet. Combined with additive manufacturing technology, a prototype of the designed variable winglet is manufactured. single bending and repeated bending test were carried out. The results showed that the deformation data and the simulation results are in good agreement, and the designed variable winglet has good deformation ability and effect. Finally, the influence of the cooling rate of the SMA rods on the deformation ability of winglet was analyzed, the reason for the skin buckling during the deformation was evaluated and the follow-up research plan was proposed.