共查询到20条相似文献,搜索用时 31 毫秒
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考虑参数不确定性的转子系统瞬态动平衡研究 总被引:1,自引:0,他引:1
针对含不确定性参数的转子系统,提出了一种基于区间数学、泰勒展开和摄动理论的转子瞬态响应区间分析法.该方法求解不确定性问题时无需不确定参数的具体概率分布,适用于一般性工程分析.利用转子瞬态响应信息对一弹性支承双盘转子进行瞬态动平衡.将不确定性引入动平衡过程,分析了不同不确定性水平下不确定性参数对瞬态动平衡效率的影响.研究结果表明,该方法能有效分析转子不确定性瞬态响应,随着不确定水平增大,转子动平衡效率大幅降低. 相似文献
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为了提高新型传感器柔性结构振动抑制能力,提出基于遥测技术的新型传感器柔性结构振动优化控制方法。在速度坐标系、体坐标系下构建新型传感器柔性结构的振动动力学模型,采用卡尔曼滤波方法实现对新型传感器柔性结构振动参数的融合调节和小扰动抑制。采用气弹模态参数识别方法,进行新型传感器柔性结构的振动模态参数识别,提取新型传感器柔性结构振动特征量,采用遥测技术进行新型传感器柔性结构振动惯性参数识别,结合状态反馈调节方法进行稳定性控制,实现新型传感器柔性结构振动优化控制。仿真结果表明,采用该方法进行新型传感器柔性结构振动优化控制的自适应性较好,具有很好的振动抑制和控制能力。 相似文献
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转子系统的稳定性是评价旋转机械性能的重要指标之一。随着对高速重载机械要求的不断提高,各式各样的非常规柔性轴承都在成功的应用或研制中,三柔性叶片主动控制滑动轴承就是针对降低转子系统的振幅以提高其稳定性而研制的一种主动控制轴承。对轴承的结构、工作原理及其数学模型的建立过程都做了较详细的阐述,并利用比例微分(PD)控制技术和优化后的目标函数对该轴承的转子实验系统进行了实时仿真,给出了多组仿真结果。仿真结果表明该种主动控制轴承具有良好的受控性能,系统的振动响应得到较大幅度衰减。 相似文献
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弹性环挤压油膜阻尼器(Elastic ring squeeze film damper, ERSFD)具有良好的支撑作用和减振效果,但由于其结构和流场耦合行为极为复杂,使得已有的物理模型难以完整表现出ERSFD的力学特性.为了进一步探究ERSFD的力学机理,本文借助有限元仿真平台,采用双向流固耦合的计算方法,剖析弹性环与油膜之间的相互作用,获取ERSFD中油膜压力的分布规律.在此基础上,利用最小二乘法进一步拟合出ERSFD等效刚度、等效阻尼与转子轴颈扰动位移的映射关系,并将其分别引入柔性转子系统动力学模型中.通过数值计算研究了ERSFD支撑下柔性转子系统的振动响应,分别给出了不同转速下转子系统的响应分岔图、轴心轨迹等.同时,通过对比分析,进一步揭示了ERSFD所诱发出的转子系统丰富的非线性动力学行为,有助于对ERSFD轴承支撑特性的理解. 相似文献
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挠性智能梁的振动控制 总被引:2,自引:0,他引:2
研究采用共位配置的压电敏感器和致动器的挠性是臂梁的振动控制问题,建立了智能梁的模型,设计了一种线性反馈控制律,并应用无空维空间的LaSalle不变原理和线性半群理论证明了当敏感器和控制器的分布使得系统能镇条件成立时,所设计的控制抑制了梁的振动。 相似文献
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旋转系统的角加速度能够反映转轴对各种激励和动态干扰的响应,由此提出了一种基于电磁感应原理的永磁式旋转角加速度传感器。方法是通过永磁体建立恒定磁通,转子对磁通进行切割,存在瞬间角加速度时,传感器的输出绕组经过电磁耦合会产生与角加速度成正比的感生电动势。推导出了传感器的输出特性,并通过实验验证了传感器测量原理的正确性,经过理论分析得到旋转磁场的转速存在波动,是造成旋转系统产生角加速度的主要原因。构建了传感器系统的状态空间模型,对传感器的能控性和能观性进行了分析,并根据李雅普诺夫稳定判据,证明了传感器系统的大范围渐进稳定性。最后将传感器应用于振动转矩的测量并进行了标定,实验结果是该传感器的灵敏度约为39.08 mV/mN.m。 相似文献
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This paper derives a jerk-shaped profile to address the vibration reduction of underdamped flexible dynamics of motion system. The jerk-limited profile is a widespread smooth command pattern used by modern motion systems. The ability of the jerk-limited profile to cancel the residual vibration of an undamped flexible mode is clearly explained using an equivalent continuous filter representation and the input shaping formalism. This motivates the design of a new jerk-shaped profile, named Damped-Jerk profile, to extend the previous result to the more common case of underdamped systems. Both simulations and experimental results demonstrate the effectiveness of the proposed Damped-Jerk profile to reduce damped vibration. 相似文献
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本文采用柔性多体系统单向递推组集的建模方法,基于速度变分原理建立了带Stewart平台、柔性帆板和CMG组件的航天器刚柔耦合动力学模型.由于该模型自由度较大,无法满足实时控制的需求,因此建立了简化的Stewart平台等效模型,并通过与柔性Stewart平台完整模型对比,验证了所建立的动力学简化模型的正确性与高效性.分析了星体平台运动及柔性帆板的振动对有效载荷动力学响应的影响,指出了设计Stewart平台的微振动抑制方案时不能忽略下平台的运动及柔性附件的振动.本研究为带Stewart平台的航天器的微振动减振设计与高精度指向提供了有效的技术支撑. 相似文献
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Small Vibrations Superimposed on a Prescribed Rigid Body Motion 总被引:2,自引:0,他引:2
A method for analysing flexible multibody systems in which theelastic deformations are small is presented. The motion isconsidered a gross non-linear rigid body motion with small linearvibrations superimposed on it. For periodic gross motion, thisresults in a system of rheolinear differential equations for thedeformations with periodic coefficients. The determination of therequired equations with a program for flexible multibody systemsis discussed which calculates, besides the periodic gross motion,the linearized, or variational, equations of motion. Periodicsolutions are determined with a harmonic balance method, whiletransient solutions are obtained by an averaging method. Thestability of the periodic solutions is considered. The procedurehas a high computational efficiency and leads to more insight intothe structure of solutions. The method is applied to a pendulumwith an elliptical motion of its support point, a slider-crankmechanism with flexible connecting rod, a rotor system, and aCardan drive shaft with misalignment. 相似文献
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Distributed structural identification and control of shells using distributed piezoelectrics: Theory and finite element analysis 总被引:1,自引:0,他引:1
Distributed dynamic identification and vibration control of high-performance flexible structures has drawn much attention in recent years. This article presents an analytical and finite-element study on a distributed piezoelectric sensor and distributed actuator coupled with flexible shells and plates. The integrated piezoelectric sensor/actuator can monitor the oscillation as well as actively control the structural vibration by the direct/converse piezoelectric effects, respectively. Based on Maxwell's equations and Love's assumptions, new theories on distributed sensing and active vibration control of a generic shell using the distributed piezoelectrics are derived. These theories can be easily simplified to account for plates, cylinders, beams, etc. A new piezoelectric finite element is also formulated using the variational principle and Hamilton's principle. A piezoelectric micropositioning device was first studied; analytical solutions are compared closely with experimental and finite-element results. Distributed vibration identification and control of a zero-curvature shell-a plate-are also investigated. 相似文献
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This work treats the problem of modelling multibody systems with structural flexibility. By combining linear graph theory
with the principle of virtual work and finite elements, a dynamic formulation is obtained that extends graph-theoretic (GT)
modelling methods to the analysis of thin flexible plates for multibody systems. The system is represented by a linear graph,
in which nodes represent reference frames on flexible plates, and edges represent components that connect these frames. To
generate the equations of motion with elastic deformations, the flexible plates are discretized using a triangular thin shell
finite element based on the discrete Kirchhoff criterion and can be used to discretize bidirectional bodies such as satellite panels, flatbed trailers, and mechanisms with
plates. Three flexible systems with plates are analyzed to illustrate the performance of this new variational graph-theoretic
formulation and its ability to generate directly a set of motion equations for flexible multibody systems (FMS) without additional
user input. 相似文献
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A.J. Edwards 《Computer aided design》1973,5(3):139-146
This paper describes a torsional vibration analysis program suitable for handling multi-junction multi-branched systems with damping and excitation torques (provided by engines, compressors, marine propellers, etc) applied at many points in the individual branches. The method used is the 2 × 2 matrix method, developed by the British Internal Combustion Engine Research Institute, for branched systems.This method is considered to be a major advance on other methods of vibration analysis since it is faster and cheaper for repeated use than either the current Holzer table method, the field matrix method or the iteration methods. It is also more flexible, permitting the user to include modifications and to ask various questions concerning the behaviour of specific parts of the installation investigated, to which specific answers are provided without having to evaluate all the conditions at all points in the system. 相似文献
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An efficient direct differentiation approach for sensitivity analysis of flexible multibody systems 总被引:1,自引:0,他引:1
This paper presents a recursive direct differentiation method for sensitivity analysis of flexible multibody systems. Large
rotations and translations in the system are modeled as rigid body degrees of freedom while the deformation field within each
body is approximated by superposition of modal shape functions. The equations of motion for the flexible members are differentiated
at body level and the sensitivity information is generated via a recursive divide and conquer scheme. The number of differentiations
required in this method is minimal. The method works concurrently with the forward dynamics simulation of the system and requires
minimum data storage. The use of divide and conquer framework makes the method linear and logarithmic in complexity for serial
and parallel implementation, respectively, and ideally suited for general topologies. The method is applied to a flexible
two arm robotic manipulator to calculate sensitivity information and the results are compared with the finite difference approach. 相似文献
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Ken Sasaki Yuji Osaki Jun Okazaki Hiroshi Hosaka Kiyoshi Itao 《Microsystem Technologies》2005,11(8-10):965-969
Two types of electric power generator systems that automatically extract power from oscillating motion of a human body or vibration of machines and structures are proposed and studied. The first system utilizes self-excited rotation of an eccentric rotor that rotates in one direction in synchronization with the applied oscillating motion. Connecting an electrical load to the generator increases the damping about the rotor axis, and numerical analysis shows that there exists an upper limit to this damping to maintain the self-excited rotation mode. Excessive damping reduces the rotor to a swinging motion, resulting in decreased power output. The second type utilizes resonant vibration of a permanent magnet unit suspended by a set of springs. In order to maximize the output power, a micro controller changes the connection of the generator coils, which in effect changes the electro-mechanical damping, to keep the vibration amplitude within the allowable stroke. Theoretical analysis and experimental results are presented for both systems. 相似文献