沿均匀无限介质中固体杆传播的导波特性研究

Guided waves in a rod surrounded by an infinite solid medium

针对均匀无限固体介质包围的无限长固体杆,研究了沿固体杆传播的导波的频散和激发特性。在理论分析的基础上,用二分法快速求取了导波所有模式的频散曲线,在4种介质参数下,对斯东利模式和简正模式进行了深入的分析和总结;研究了固体杆中导波的激发强度特性,分别在对称点源、轴向力源和径向力源激励下,研究了导波诸模式的激发机理及频谱特性,分析了不同频段导波的主导模式,研究了主导模式的频响特性及位移径向分布关系。

The dispersion and excitation characteristics of the guided waves in a rod surrounded by an infinite solid cladding are investigated.The bisection technique is employed to find all the roots of the dispersion function on the basis of theoretical analysis.The Stoneley and Normal modes are analyzed further in four groups of the medium parameters.The excitation intensities of the guided waves are studied for the first time.The excitation mechanism and frequency spectrum of the guided waves excited by the symmetric source,axial and radial force sources are investigated respectively.The dominant modes in different frequency ranges are analyzed.Moreover,for the dominant modes,the frequency spectrum characteristic and the relationship between the displacement and the radial distance are studied.