排序方式: 共有17条查询结果,搜索用时 31 毫秒
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替代数据法作为检验时间序列非线性和混沌的统计方法获得了广泛的应用.由于原替代数据法的零假设为线性高斯过程,可能把线性非高斯过程,特别是非最小相位过程误判为非线性.为了解决这一问题,提出并详细推导了基于功率谱等价的非最小相位序列求逆方法;结合基于高阶累积量的非最小相位自回归滑动平均模型辨识方法,提出了检验序列是否为线性非高斯过程的替代数据生成新算法.仿真算例表明,上述方法成功地克服了原替代数据法的不足.
关键词:
替代数据
非线性检验
非最小相位
功率谱等价 相似文献
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Flexural vibration band gaps in thin plates with two-dimensional binary locally resonant structures 下载免费PDF全文
The complete flexural vibration band gaps are studied in the thin plates
with two-dimensional binary locally resonant structures, i.e. the composite
plate consisting of soft rubber cylindrical inclusions periodically placed
in a host material. Numerical simulations show that the low-frequency gaps
of flexural wave exist in the thin plates. The width of the first gap
decreases monotonically as the matrix density increases. The frequency
response of the finite periodic thin plates is simulated by the finite
element method, which provides attenuations of over 20dB in the frequency
range of the band gaps. The findings will be significant in the application
of phononic crystals. 相似文献
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通过引入振动力学中的连续系统离散化的思想,将一维集中质量法延伸至二维,提出一种二维声子晶体带隙特性计算的集中质量法. 进而采用该算法对两种正方晶格的二维声子晶体的带结构进行了计算,计算结果与传统的平面波展开法相符合. 通过对计算结果以及两种算法收敛性的分析,发现集中质量法的收敛性对组成声子晶体的不同材料弹性参数差不敏感,这使得该算法在计算大弹性常数差二维声子晶体的带隙特性时较平面波展开法收敛速度更快. 此外,集中质量法对二维声子晶体单元形状没有特殊要求,这使得它更加适用于声子晶体带隙特性的计算.
关键词:
声子晶体
声子带隙
集中质量法 相似文献
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Directional Propagation Characteristics of Flexural Waves in Two-Dimensional Thin-Plate Phononic Crystals 下载免费PDF全文
The propagation characteristics of flexural waves in two-dimensional thin-plate phononic crystals (PCs) are analysed with the plane wave expansion (PWE) method to yield phase constant surfaces, which predict high directivity of flexural wave propagation for certain frequencies outside the band gap. The prediction is validated through the computation of the harmonic responses of a finite structure with 9 × 9 unit cells. The results indicate that directional propagation of flexural waves is an while specific effects of the directional propagation in inherent characteristic of two-dimensional thin-plate PCs a finite structure vary with the positions of excitations. 相似文献
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The acoustic properties of locally resonant sonic materials with viscosity are theoretically investigated by using the multiple-scattering approach. We find that the absorption of a two-layer slab dominates the wave attenuation in the resonant frequency region under the condition of moderate or high viscous level. The fundamental mechanism operating in local resonance for absorption is investigated for the viability by the mode translation in the scattering process of a single scatterer. Finally the absorption performance in a multi-layer system is discussed. 相似文献
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相位常数面可以描述特定频率、特定结构中波的传播方向及传播区域.将相位常数面这一分析方法应用于薄板状周期栅格结构中弹性波传播特性的研究,采用集中质量法计算了周期栅格结构的相位常数面,得到了直观的三维能带结构图.相位常数面可以用二维等高线图描述,通过计算等高线上每一点的法线方向,得到了在特定通带频率下弹性波的传播方向及传播区域.这些研究对于通带频率范围内的弹性波传播特性具有重要意义.
关键词:
声子晶体
弹性波带隙
集中质量法
相位常数面 相似文献
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Using an exact Mie scattering solution, this paper investigates the mode conversions during the Mie scattering of a single bi- or one-component sphere in unbounded epoxy. Then the formation mechanism of the first complete gap in the corresponding tri- or bi-component phononic crystal is investigated by the multiple-scattering method. It is shown that the heavy density of the scatterer plays an essential role in the Mie resonance and the formation of the gaps for both types of the phononic crystals. For the tri-component phononic crystal, the gap is mainly induced by the Mie resonance of the single scatterer. For the bi-component phononic crystal, the transverse wave (by mode-conversion during the Mie scattering under a longitudinal wave incidence) is modulated by the periodicity and governed by the Bloch theory, which induces the gap cooperatively. 相似文献