【作者】 王晓莉；

【导师】 刘书田； 胡和平；

【作者基本信息】 大连理工大学 ， 机械工程， 2025， 硕士

【摘要】 直升机容易受到高振动水平的影响,基于智能材料的压电作动器的开发使得通过开发智能直升机旋翼直接解决这一高振动问题成为可能。智能旋翼的基本思想是在旋翼桨叶上产生新的非稳态空气动力和力矩,从而抵消现有的力和力矩,而这些力和力矩是直升机振动的主要来源。本文针对直升机减振问题,开展了基于智能材料驱动技术的主动扭转旋翼系统研究与试验验证。首先,针对弹性旋翼桨叶,建立了旋翼结构动力学分析模型,构建了多体坐标系下的旋翼桨叶运动描述体系。利用广义Hamilton原理构建了桨叶动力学变分方程,推导了桨叶的动能、应变能以及气动力虚功,并通过有限元离散化方法求解旋翼的动力学方程。该结构动力学模型可用于桨叶模态计算、运动与变形分析,选取了均匀对称模型桨叶进行验证,结果表明所提建模方法在旋翼动力学建模中具有较高的精度和工程适用性。其次,研究了主动扭转桨叶的变形规律,采用有限元方法分析了压电纤维复合材料驱动的悬臂梁作动特性,推导了压电-弹性耦合本构方程,建立了MFC驱动的压电悬臂结构的机电耦合有限元模型,并通过数值分析探讨了纤维角度、铺设位置及基板材料等设计参数对桨叶变形特性的影响。通过分析压电纤维复合材料铺设参数的变化对结构形变响应的作用机制,研究表明纤维方向与主动扭转桨叶展向呈45°夹角时,MFC的作动效率最优。最后,基于遗传算法构建多目标优化模型对可变形桨叶的压电驱动结构布局的进行优化设计,以驱动器的铺设位置、铺设角度为设计变量,模型桨叶变形模式为目标,优化得到了最优驱动器铺设位置与铺设角度。根据优化得到的方案,设计了两种变形试验方案,可变形平板挥舞试验和模型桨叶扭转变形试验验证,测得试验与仿真误差小于5%,通过试验验证了数值方法与优化方案的工程适用性。更多还原

【Abstract】 Helicopters are susceptible to high vibration levels and the development of smart material based piezoelectric actuators has made it possible to directly address this high vibration problem through the development of smart helicopter rotors.The basic idea of smart rotor blades is to generate new unsteady aerodynamic forces and moments on the rotor blades,thereby counteracting the existing forces and moments,which are the main source of helicopter vibration.Firstly,the research and experimental validation of an active torsion rotor system based on smart material actuation technology is carried out to address the problem of helicopter vibration damping.First,for the elastic rotor blade,a rotor structure dynamics analysis model is established,and the rotor blade motion description system under multi-body coordinate system is constructed.The generalized Hamilton’s principle is used to construct the rotor dynamics variational equations,derive the kinetic energy,strain energy,and aerodynamic virtual work of the rotor,and solve the rotor blade’s dynamics equations by the finite element discretization method.The structural dynamics model can be used for rotor modal calculation,motion and deformation analysis,and a uniformly symmetric model rotor is selected for validation,and the results show that the proposed modeling method has high accuracy and engineering applicability in rotor blade dynamics modeling.Secondly,the deformation law of the active torsional blade was studied.The actuation characteristics of the cantilever beam driven by piezoelectric fiber composite materials were analyzed using the finite element method.The piezoelectric-elastic coupling constitutive equation was derived,and the electromechanical coupling finite element model of the piezoelectric cantilever structure was established.Through numerical analysis,the influence of design parameters such as fiber angle,laying position,and substrate material on the blade deformation characteristics was explored.By analyzing the influence of different laying methods of piezoelectric fiber composite materials(MFC)on structural deformation,it was shown that when the fiber direction is at a 45°angle with the longitudinal direction of the active torsional blade,the actuation efficiency of MFC is optimal.Finally,a multi-objective optimization model based on genetic algorithm was constructed to optimize the layout of the piezoelectric-driven deformable rotor.The design variables were the placement position,placement angle,and number of layers of the actuator,and the target was the deformation mode of the base plate.The optimal placement position and angle of the actuator were obtained through optimization.Based on the optimized scheme,two deformation test schemes were designed,namely the flap test of the deformable plate and the torsional deformation test of the model rotor blade.The test results had an error of less than 5%compared with the simulation results.The engineering applicability of the numerical method and the optimization scheme was verified through the test.更多还原