共查询到19条相似文献,搜索用时 218 毫秒
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扁壳结构的弯曲与扭转振动控制对该类结构的应用具有重要意义。本文采用不影响壳体结构的粗压电纤维复合材料(MFC)作动器对其弯曲与扭转振动进行主动控制。建立局部表面粘贴MFC作动器的开口圆柱扁壳的动力学解析模型,得到了作动力和作动力矩的解析表达式,分析了扁壳结构上MFC作动器在弯曲与扭转振动控制中的作动机理。针对一开口碳纤维圆柱扁壳,设计了模糊PD控制器,开展了定频与随机激励下壳体弯曲与扭转振动控制试验,并与传统PD控制试验效果进行了对比。结果表明:MFC作动器在壳体弯曲和扭转振动控制方面作动能力突出;模糊PD控制器的控制效果优于传统PD控制器的控制效果。 相似文献
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基于弹性、粘弹性和压电材料本构方程,应用能量法建立了主动约束层阻尼(ACLD)圆柱壳体的有限元动力学方程。通过对压电传感层自感电压的比例、微分反馈控制,对主动约束层阻尼(ACLD)圆柱壳体进行了主被动一体化振动控制,研究了复合圆柱壳体的动力学响应特性。讨论了主动约束层阻尼(ACLD)片体的位置、覆盖率、粘弹性层厚度及控制增益等关键参数对圆柱壳体振动特性的影响。研究表明:主动约束层阻尼(ACLD)片体的粘贴位置与模态有关,针对不同模态,应采用不同的粘贴位置;覆盖率、粘弹性层厚度及控制增益等直接影响到振幅衰减程度,通过对片体位置、覆盖率、粘弹性层厚度及控制增益等关键参数的优化,能有效降低主动约束层阻尼圆柱壳体的振动,具有十分重要的工程应用价值。 相似文献
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旋转运动柔性梁的时滞主动控制实验研究 总被引:8,自引:0,他引:8
对旋转运动柔性梁的时滞主动控制进行实验研究,验证时滞反馈控制的有效性. 实验中采用交流伺服电机带动柔性梁旋转运动,柔性梁上粘贴有压电作动器,用于控制梁的弹性振动. 实验研究考虑如下3种情况:(1)仅使用电机扭矩进行控制,电机扭矩存在时滞;(2)使用电机扭矩和压电作动器同时控制,仅压电作动器存在时滞;(3)使用电机扭矩和压电作动器同时控制,电机和压电作动器存在不同的时滞量. 重点通过实验验证时滞反馈控制的可行性和有效性. 相似文献
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压电复合材料层合板自适应结构的振动控制 总被引:10,自引:0,他引:10
本文针对板壳型自适应结构,研究了压电材料作为作动器的自适应结构的振动控制。利用四节点压电复合材料层合板单元进行自适应结构的有限元动力分析;采用模态控制方法,将结构的各阶模态的阻尼比作为控制目标,并以此计算出各压电片的控制电压,达到控制结构振动的目的。算例给出了数值计算的结果。 相似文献
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一种逆优化设计振动控制作动器的数目和位置的方法 总被引:1,自引:0,他引:1
在建立了悬臂梁上粘贴压电陶瓷片实现振动控制的动力学方程的基础上,研究了一种逆优化设计作动器/传感器的数目和位置的方法;用压电陶瓷作为自传感器作动器,以悬臂梁的振动控制为研究对象,要求振动控制系统具有一定的模态阻尼比,并以作动器控制力最小为目标函数,优化设计作动器/传感器的数目和位置。最后通过数值算例证明了该方法的有效性。 相似文献
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压电作动器可以把电能转换成机械能,在结构主动振动控制中具有应用背景. 由于压电作动器的布局对振动控制效果影响很大,因此作动器布局优化一直是结构控制研究的关键之一. 为了提高压电结构控制能量的利用效率,本文提出了以提高结构可控性为目标的压电作动器的拓扑优化方法. 基于经典层合板理论对压电结构进行了有限元建模,并采用模态叠加法将动力控制方程映射到模态空间,推导了基于控制矩阵奇异值的可控性指标. 优化模型中,选取可控性指标指数形式为目标函数,将设计变量定义为作动器单元的相对密度,并基于人工密度惩罚模型构造了压电系数惩罚模型,给出了基于控制矩阵奇异值的可控性指标关于设计变量的灵敏度分析方法. 优化问题采用基于梯度的数学规划法求解. 数值算例验证了灵敏度分析方法和优化模型的有效性,并讨论了主要因素对优化结果的影响. 相似文献
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压电作动器可以把电能转换成机械能,在结构主动振动控制中具有应用背景.由于压电作动器的布局对振动控制效果影响很大,因此作动器布局优化一直是结构控制研究的关键之一.为了提高压电结构控制能量的利用效率,本文提出了以提高结构可控性为目标的压电作动器的拓扑优化方法.基于经典层合板理论对压电结构进行了有限元建模,并采用模态叠加法将动力控制方程映射到模态空间,推导了基于控制矩阵奇异值的可控性指标.优化模型中,选取可控性指标指数形式为目标函数,将设计变量定义为作动器单元的相对密度,并基于人工密度惩罚模型构造了压电系数惩罚模型,给出了基于控制矩阵奇异值的可控性指标关于设计变量的灵敏度分析方法.优化问题采用基于梯度的数学规划法求解.数值算例验证了灵敏度分析方法和优化模型的有效性,并讨论了主要因素对优化结果的影响. 相似文献
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New matrix method for analyzing vibration and damping effect of sandwich circular cylindrical shell with viscoelastic core 总被引:2,自引:0,他引:2
Based on the linear theories of thin cylindrical shells and viscoelastic materials, a governing equation describing vibration of a sandwich circular cylindrical shell with a viscoelastic core under harmonic excitation is derived. The equation can be written as a matrix differential equation of the first order, and is obtained by considering the energy dissipation due to the shear deformation of the viscoelastic core layer and the interaction between all layers. A new matrix method for solving the governing equation is then presented With an extended homogeneous capacity precision integration approach. Having obtained these, vibration characteristics and damping effect of the sandwich cylindrical shell can be studied. The method differs from a recently published work as the state vector in the governing equation is composed of displacements and internal forces of the sandwich shell rather than displacements and their derivatives. So the present method can be applied to solve dynamic problems of the kind of sandwich shells with various boundary conditions and partially constrained layer damping. Numerical examples show that the proposed approach is effective and reliable compared with the existing methods. 相似文献
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《International Journal of Solids and Structures》2006,43(13):3705-3722
This paper is concerned with the free vibration of open circular cylindrical shells with intermediate ring supports. An analytical procedure for determining the free vibration frequencies of such shells is developed based on the Flügge thin shell theory. An open circular cylindrical shell is assumed to be simply supported along the two straight edges and the remaining two opposite curved edges may have any combinations of support conditions. The shell is divided into multiple segments along the locations of the intermediate ring supports. The state-space technique is employed to derive the exact solutions for each shell segment and the domain decomposition method is applied to enforce the geometric and natural boundary/interface conditions along the interfaces of the shell segments and the curved edges of the shell. Comparison studies are carried out to verify the correctness of the proposed method. Exact vibration frequencies are obtained for open circular cylindrical shells with multiple intermediate ring supports.The influence of the number of intermediate ring supports, the locations of the ring supports, the boundary conditions and the variation of the included angle of the shells on the natural frequencies are examined. The exact vibration solutions can be used as important benchmark values for researchers to check their numerical methods and for engineers to design such shell structures. 相似文献
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Free vibration characteristics of circular cylindrical shell with passive constrained layer damping (PCLD) are presented.
Wave propagation approach rather than finite element method, transfer matrix method, and Rayleigh-Ritz method is used to solve
the problem of vibration of PCLD circular cylindrical shell under a simply supported boundary condition at two ends. The governing
equations of motion for the orthotropic cylindrical shell with PCLD are derived on the base of Sanders’ thin shell theory.
Numerical results show that the present method is more effective in comparison with other methods. The effects of the thickness
of viscoelastic core and constrained layer, the elastic modulus ratio of orthotropic constrained layer, the complex shear
modulus of viscoelastic core on frequency parameter, and the loss factor are discussed. 相似文献
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Analysis of laminated piezoelectric cylindrical shells 总被引:2,自引:0,他引:2
A new method is developed for three-dimensional stress analysis of laminated piezoelectric cylindrical shell with simple support.
The shell can be subjected to various applied loadings, including distributed body force, inner and outer surface traction
and potential. Each layer of the shell can be piezoelectric or elastic/dielectric, with perfect bonding assumed between each
interface. The governing equations are solved by the state-space technique. Numerical results are presented to show the sensing
and actuating effects of three-layered piezoelectric cylindrical shell.
The project supported by the National Natural Science Foundation of China (19572027) 相似文献
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The free flexural vibration of a hung clamped-free cylindrical shell partially submerged in a fluid is investigated. The fluid is assumed to be inviscid and irrotational. The cylindrical shell is modelled by using the Rayleigh-Ritz method based on Sanders’ shell theory. The kinetic energy of the fluid is derived by solving the boundary-value problem related to the fluid motion. The natural vibration characteristics of the partially submerged cylindrical shell are discussed with respect to the added virtual mass approach. In this study, the nondimensionalized added virtual mass incremental factor for the partially submerged finite shell is derived. This factor can be readily used to estimate the change in the natural frequency of the shell due to the presence of a fluid. 相似文献
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LuoDonning CaiMinbo PengXu LuoBin 《Acta Mechanica Solida Sinica》2003,16(2):155-161
The Donnell theory of shell is applied to describe shell motion and layer motion is described by means of three-dimensional Navier equations. Using deformation harmonious conditions of the interface, the effects of stiffeners and layer are treated as reverse forces and moments acting on the cylindrical shell. In studying the acoustic field produced by vibration of the submerged ring-stiffened cylindrical coated shell, the structure dynamic equation, Helmholtz equation in the fluid field and the continuous conditions of the fluid-structure interface compose the cou-pling vibration equation of the sound-fluid-structure. The extract of sound pressure comes down to the extract of coupling vibration equation. By use of the solution of the equation, the influences of hydrostatic pressure, physical characters and geometric parameters of the layer on sound radiation are discussed. 相似文献