共查询到20条相似文献,搜索用时 109 毫秒
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支架振动的主动控制研究 总被引:1,自引:1,他引:1
利用压电材料的机电耦合特性,采用数值分析和实验相结合的方法研究了压电材料对支架的振动控制。利用Hamilton原理,采用速度反馈,并考虑压电材料的机电耦合效应推导了振动主动控制有限元方程,分析了不同约束,不同压电片布置情况下支架的振动控制,实现了压电片的优化布置,同时用实验验证了数值分析的正确性。 相似文献
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压电桁架结构的稳定性及有限元分析方法 总被引:5,自引:0,他引:5
从力的平衡方程出发,考虑机电耦合效应,推导了含压电材料的桁架结构稳定性有限元方程。通过数值算例分析表明,机电耦合效应对桁架结构的稳定性影响较在,而电压对结构稳定性的影响相对较小,压电杆的优化布置能够有效地提高结构稳定性。 相似文献
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压电介质有限变形的增量变分方程 总被引:1,自引:0,他引:1
从连续介质力学的基本理论出发,导出了压电介质几种非线性率型变分方程,在定义了各种增量之后,由率型变分方程得到了四种增量变分方程,即压电介质的TotalLagrange和UpdatedLagrange变分方程,它们是导出压电介质非线性有限元方程的基础,也可用于推导其它的简化理论。 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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By applying the Heaviside function, the equations governing laminated plates possessing spatially distributed piezoelectric
patches have been established. Based on these equations, static shape control of laminated plates is discussed. By using a
genetic and collocation algorithm, the optimal locations and scales of these piezoelectric patches have been selected. Numerical
examples are presented to illustrate the efficiency of the algorithm and the piezoelectric actuators. 相似文献
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首先借助阶梯函数,建立了含有任意分布的用作执行器的压电片的梁挠曲轴线方程。然后利用该方程,进行了梁的静变形控制的研究。最后结合实例,用“遗传+配点”法对压电片的位置和尺寸进行了优化。结果表明,本文建立的挠曲方程形式简洁,求解简单:“遗传+配点”法优化效果明显。 相似文献
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Piezoelectric generator based on torsional modes for power harvesting from angular vibrations 总被引:1,自引:0,他引:1
Torsional vibration of a circular piezoelectric shell of polarized ceramics mounted on a rotationally vibrating base is analyzed. The shell is properly electroded and connected to a circuit such that an electric output is generated. The structure analyzed represents a piezoelectric generator for converting mechanical energy from angular vibrations to electrical energy. Analytical expressions and numerical results for the output voltage, current, power, efficiency and power density are given. 相似文献
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板壳结构作为航空、航天工程以及控制系统中的重要工作元件,在工作状态
中,要承受机械载荷、温度载荷、冲击载荷等各种负面影响,
而航空航天部件对结构形状变化非常敏感,如飞行器机翼、信息接收天线等结构,
微小的结构变形就会引起很大的性能改变,想要在设计初始阶段充分考虑所有不
利因素的影响显然是比较困难的. 利用压电材料控制结构变形往往是现代空间结
构开关控制中一个很好的选择. 基于一般壳体有限单元法, 推导了空间任意曲壳
压电单元, 利用约束方程连接主体壳元和压电壳元, 模型中约束方程的使用大大
减少了结构自由度, 使得计算速度有了明显的提升. 在此基础上, 重点研究了压
电曲壳结构的形状控制方法, 首先利用最小二乘法优化结构的电压分布, 控制结
构形状接近最优工作状态; 其次构建了以压电壳元厚度和电压联合作为设计变量
的优化控制模型, 采用非线性优化求解方法, 取得了更好的控制效果. 数值算例
表明了该文计算模型、 优化设计和控制方法的有效性. 相似文献
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A theoretical model is proposed in this paper to predict the bi-stable states of initially stressed cylindrical shell structures attached by surface anisotropic piezoelectric layers.The condition for existence of bi-stability of the shell structural system is presented and analytical expressions for corresponding rolled-up radii of the stable shell are given based on the principle of minimum strain energy.The resulting solution indicates that the shell system may have two stable configurations besides its initial state under a combined action of the actuating electric field and initial stresses characterized by the bending moment.If the piezoelectric layer materials act as only sensor materials without the actuating electric field,initial stresses may produce the bi-stable states,but one corresponding to its initial state.For the shell without initial stresses,the magnitude in the actuating electric field determines the number of the stable states,one or two stable configurations besides the initial state.The theoretical prediction for the bi-stable states is verified by finite element method(FEM) simulation by using the ABAQUS code. 相似文献
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《International Journal of Solids and Structures》2006,43(6):1388-1403
A modified mixed variational principle for piezoelectric materials is established and the state-vector equation of piezoelectric plates is deduced directly from the principle. Then the exact solution of the state-vector equation is simply given, and based on the semi-analytical solution of the state-vector equation, a realistic mathematical model is proposed for static analysis of a hybrid laminate and dynamic analysis of a clamped aluminum plate with piezoelectric patches. Both the plate and patches are considered as two three-dimensional piezoelectric bodies, but the same linear quadrilateral element is used to discretize the plate and patches. This method accounts for the compatibility of generalized displacements and generalized stresses on the interface between the plate and patches, and the transverse shear deformation and the rotary inertia of the plate and patches are also considered in the global algebraic equation system. Meanwhile, there is no restriction on the thickness of plate and patches. The model can be also modified to achieve a semi-analytical solution for the transient responses to dynamic loadings and the vibration control of laminated plate with piezoelectric patches or piezoelectric stiffeners. 相似文献
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Hanen Jrad Hanen Mallek Mondher Wali Fakhreddine Dammak 《Comptes Rendus Mecanique》2018,346(12):1159-1178
For the analysis and design process of smart structures with integrated piezoelectric patches, the finite element method provides an effective simulation approach. In this paper, an attempt on modeling and simulation of the behavior of hybrid active structures is carried out using developed Kirchhoff-type-four-node shell element.The finite element results are compared with reference solutions taking into account the electromechanical responses of smart structures with various geometries, and the results show very high agreement. The main aspect of the application of the proposed element is to predict the behavior of FGM shells containing piezoelectric layers. A set of numerical analyses is performed in order to highlight the applicability and effectiveness of the present finite element model, notably for smart FGM structures. A comprehensive parametric study is conducted to show the influence of material composition, the placement and the thickness of the piezoelectric layers on the deformation of the laminated structure. 相似文献