基于zig-zag板壳假设和哈密顿原理建立了压电阻尼层合结构的机电耦合动力学有限元模型,实现了结构自然频率和损耗系数的准确计算。有限元模型采用八节点的七自由度(degrees of freedom,DOFs)四边形单元,且考虑阻尼层的复弹性模量。通过...基于zig-zag板壳假设和哈密顿原理建立了压电阻尼层合结构的机电耦合动力学有限元模型,实现了结构自然频率和损耗系数的准确计算。有限元模型采用八节点的七自由度(degrees of freedom,DOFs)四边形单元,且考虑阻尼层的复弹性模量。通过对文献算例的计算与仿真,验证建立的有限元模型的正确性。研究了材料增强角度、阻尼层厚度和结构曲率对压电阻尼层合结构频率和损耗系数的影响,为压电阻尼层合结构的减振及结构优化提供参考。展开更多
This paper investigates the radiation characteristics of metal single-walled zig-zag carbon nanotubes as a dipole antenna at terahertz wave range. The current distribution, input impedance and mutual impedance are cal...This paper investigates the radiation characteristics of metal single-walled zig-zag carbon nanotubes as a dipole antenna at terahertz wave range. The current distribution, input impedance and mutual impedance are calculated for various geometrical parameters of vertically-aligned carbon nanotubes. The numerical results demonstrate the properties of the antenna depending strongly on the geometrical parameters such as the radius, the lengths of carbon nantobues, and the spacing between nanotubes. It is found that the zig-zag carbon nanotubes exhibit very high input impedance and the mutual impedances for antenna array applications. These unique high impedance properties are different from the conventional metal thin wire antenna. The far-field patterns and gain of antenna array are also calculated. The maximum gain of array of 100-element array is up to 20.0 dB, which is larger than the gain of 0.598 dB of single dipole antenna at distance d = 0.5λ.展开更多
文摘基于zig-zag板壳假设和哈密顿原理建立了压电阻尼层合结构的机电耦合动力学有限元模型,实现了结构自然频率和损耗系数的准确计算。有限元模型采用八节点的七自由度(degrees of freedom,DOFs)四边形单元,且考虑阻尼层的复弹性模量。通过对文献算例的计算与仿真,验证建立的有限元模型的正确性。研究了材料增强角度、阻尼层厚度和结构曲率对压电阻尼层合结构频率和损耗系数的影响,为压电阻尼层合结构的减振及结构优化提供参考。
基金Project supported by the National Natural Science Foundation of China (Grant No.60571026)the Open Project of State Key Laboratory of Millimeter Wave (Grant No.K201006)the Science and Technology Research Foundation of Heilongjiang Education Bureau of China (Grant No.11531055)
文摘This paper investigates the radiation characteristics of metal single-walled zig-zag carbon nanotubes as a dipole antenna at terahertz wave range. The current distribution, input impedance and mutual impedance are calculated for various geometrical parameters of vertically-aligned carbon nanotubes. The numerical results demonstrate the properties of the antenna depending strongly on the geometrical parameters such as the radius, the lengths of carbon nantobues, and the spacing between nanotubes. It is found that the zig-zag carbon nanotubes exhibit very high input impedance and the mutual impedances for antenna array applications. These unique high impedance properties are different from the conventional metal thin wire antenna. The far-field patterns and gain of antenna array are also calculated. The maximum gain of array of 100-element array is up to 20.0 dB, which is larger than the gain of 0.598 dB of single dipole antenna at distance d = 0.5λ.
