高速旋转柔性梁振动分析与智能控制研究

发布时间：2018-03-16 11:31

本文选题：高速旋转　切入点：柔性梁　出处：《南京航空航天大学》2016年博士论文　论文类型：学位论文

【摘要】：半个多世纪以来,旋转结构大量出现,并广泛应用于航空、航天等领域,其中绕自身轴线的旋转结构广泛应用于卫星的旋转支架、横轴旋翼机、机械轴等。旋转梁在高速旋转时,由自身的材料分布不均、外界扰动等原因引起的振动会引发飞行器的结构疲劳、安全性下降等问题,因此对此类旋转梁结构进行动力学分析及控制有着极其重要的意义。本文主要针对两端简支梁动力学模型进行了较为深入的研究,对压电作动器的动态性能、高速旋转柔性梁的动力学建模、有限元模型、模型降阶和振动控制进行了研究,并对旋转层合梁的热冲击响应及控制进行了研究。论文的具体研究内容如下:(1)对压电材料在高电压激励下的非线性特性及一端固支双压电晶片元件在不同电压比的直流、交流激励下的柔度进行了研究。结果表明直流激励对压电作动器的柔度的影响较小,而在交流激励下表现出不同的特性,其柔度随着交流电的强度增加而增加,但不受频率的影响。在此基础上建立了一端固支双压电晶片元件受交流电压激励时的动力学方程,其动态刚度与实验测得的数据具有较高的吻合度,从而验证了理论模型的正确性。(2)基于一阶近似理论对大变形下绕自身纵轴高速旋转的柔性梁进行了动力学分析。考虑了轴向与横向振动之间的耦合作用以及由偏心产生的离心力作用;采用Hamilton原理导出了旋转柔性梁在恒定转速下动力学方程,并分别采用假设模态法及有限元素法对所得动力学方程进行分析,得出恒定转速下柔性梁一阶近似模型与零阶近似模型动力学响应。二者对比表明柔性梁在低速旋转时刚柔耦合项的影响较小,可以忽略,可采用零阶近似模型;而在高速旋转时刚柔耦合项的影响较大,不可以忽略,应采用一阶近似模型以得到较为精确的结果。(3)采用压电分流控制方法对旋转柔性梁进行振动抑制,在分析旋转梁压电分流控制方程的基础上采用模拟退火算法对电路中的电阻、电感元件进行了优化。首先使用Hamilton原理建立了绕自身纵轴旋转柔性梁的压电分流阻尼控制方程,推导了基于压电分流控制的压电分流系统传递函数。建立传递函数的优化模型,并基于模拟退火优化算法思想对目标函数进行优化。最后针对旋转梁压电分流电路优化进行数值计算与分析。仿真结果表明:压电分流阻尼系统可以很好地抑制柔性旋转梁振动响应;与遗传算法相比,模拟退火优化算法不仅可以取得更好的优化效果,且优化效率得到了极大的提高。(4)针对绕自身纵轴高速旋转柔性梁系统,开展模型降阶和智能振动控制研究。采用内平衡模型降阶方法对系统有限元模型进行模型降阶,基于降阶模型提出模糊自适应整定PID控制算法的旋转柔性梁振动智能控制方法。研究表明内平衡模型降阶方法得到的降阶模型可以很好地逼近和代替原系统;与传统的PID控制器相比,基于降阶模型的模糊自适应整定PID控制器对旋转梁的振动抑制效果更突出,并能更好地改善系统的动态和静态性能。(5)为了解决现有的压电作动器的输出较小及在旋转结构中布置等问题,研究无接触激励式压电作用堆振动控制方法。固定在旋转梁上的导线在磁场中作切割磁感线运动,产生的控制电压对压电作用堆进行激励产生弯矩从而对旋转梁进行振动控制。运用速度反馈控制方法、模糊自适应滑模控制理论设计了控制器。结果表明无接触激励式压电作用堆能够使旋转梁的横向振动较快地衰减并能够解决旋转结构中作动器布置困难的问题,验证了控制器的有效性。(6)研究了两端简支高速旋转柔性梁在热冲击作用下的动力学响应和控制。采用Hamilton原理建立受到热冲击的旋转柔性梁的动力学方程,采用中心差分法对结构的动力学响应进行近似求解,并对热冲击状态下的热模态和频率进行研究。设计智能控制器,对旋转梁的热冲击响应进行振动控制研究。
[Abstract]:More than half a century, the emergence of a large number of rotating structure, and is widely used in aviation, aerospace and other fields, the rotating bracket structure of rotating around its own axis are widely used in satellite, the horizontal axis rotor machine, mechanical shaft. The rotating beam is rotated at a high speed, by its own material distribution is uneven, the vibration caused by external causes disturbance will cause the structural fatigue of the aircraft safety decline, so the dynamic analysis and control of the rotating beam structure has a very important significance. In this paper, the beam dynamics model is studied. The dynamic performance of the piezoelectric actuator, dynamic modeling of high speed rotating flexible beam the finite element model, model reduction and vibration control are studied, and the thermal shock of rotating laminated beam response and control were studied. The main research contents are as follows: (1) to DC side and nonlinear properties of piezoelectric materials in high voltage excitation clamped piezoelectric bimorph element in different voltage than the AC excitation flexibility were studied. The results show that the DC excitation has little influence on the flexibility of actuator of piezoelectric, and showed different characteristics in the AC excitation, the the flexibility increases with the increase of alternating current strength, but is not affected by the frequency. Based on the established clamped piezoelectric bimorph element by the kinetic equation of AC voltage excitation, the dynamic stiffness of the degree of agreement with the experimentally measured data is high, in order to verify the correctness of the theoretical model. (2) first order approximation theory of large deformation around its longitudinal axis high speed rotating flexible beam was analyzed. Based on the coupling between the axial and transverse vibration and the centrifugal force caused by eccentricity is considered by; Export Hamilton principle of rotating flexible beam dynamics under constant speed equation, and using assumed mode method and the finite element method to analyze the kinetic equation, the constant speed flexible beam first approximation model and the zero order approximate model of dynamic response. The two can ignore the ratio indicates a smaller impact on the low speed rotation rigid flexible beam when the coupling term, the zero order approximation model; and the larger effect of rigid rotating at high speed when the coupling term, can not ignore, the first order approximate model to obtain more accurate results. (3) mining of rotating flexible beam vibration suppression using piezoelectric shunt control method, based on the analysis of rotating beam piezoelectric shunt control equations using simulated annealing algorithm on the resistance of the circuit inductance was optimized. First use the Hamilton principle to build around its longitudinal axis of flexible beam The piezoelectric shunt damping control equation is derived for piezoelectric shunt system piezoelectric shunt control based on transfer function. The transfer function of the optimization model is established, and simulated annealing optimization algorithm to optimize the objective function. Finally, based on the rotating beam piezoelectric shunt circuit optimization calculation and analysis for the numerical simulation results show that the pressure. Electric shunt damping vibration of flexible rotating beam can well inhibit the response; compared with the genetic algorithm, simulated annealing algorithm not only can obtain better optimization results, and the optimization efficiency has been greatly improved. (4) for high-speed rotation around its own axis flexible beam system, carry out the research on order reduction model and intelligent vibration control. The balanced model reduction method of finite element model for model reduction, reduction of rotating flexible Liang Zhen proposed fuzzy adaptive PID control algorithm based on model order Dynamic intelligent control method. The results show that in equilibrium the reduced order model order reduction methods can be a good approximation and replace the original system; compared with the traditional PID controller, fuzzy adaptive reduced order model tuning PID controller vibration of the rotating beam based on inhibition effect is more prominent, and the static and dynamic performance and better the improvement of the system. (5) in order to solve the existing piezoelectric actuator output device arranged in the rotation and small structure problems of piezoelectric effect of pile vibration control method of contact wires are fixed on the rotating beam excitation. The magnetic line cutting motion in a magnetic field, the control voltage generated by excitation moment to vibration control of rotating beam of piezoelectric effect pile. Using speed feedback control method, adaptive fuzzy sliding mode control theory to design controller. The results show that the non-contact piezoelectric effect incentive pile Enable faster lateral vibration of rotating beam attenuation and can solve the difficult problem of actuator arrangement of rotating structure, verify the validity of proposed controller. (6) studied the response and control of simplysupported high-speed rotating flexible beam dynamics under the thermal shock. Using Hamilton principle to establish the dynamic equation is subjected to thermal shock the rotating flexible beam, the central difference approximation to the dynamic response of structure method, and study the thermal modal and frequency on thermal shock condition. The design of intelligent controller, thermal shock on the rotating beam response of the vibration control research.

【学位授予单位】：南京航空航天大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TB535

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