Mayer Andreas P
University of Regensburg, Institute for Theoretical Physics, 93040 Regensburg, Germany.
Ultrasonics. 2008 Nov;48(6-7):478-81. doi: 10.1016/j.ultras.2008.06.009. Epub 2008 Jun 20.
A theoretical description is given for the propagation of surface acoustic wave pulses in anisotropic elastic media subject to the influence of nonlinearity. On the basis of nonlinear elasticity theory, an evolution equation is presented for the surface slope or the longitudinal surface velocity associated with an acoustic pulse. It contains a non-local nonlinearity, characterized by a kernel that strongly varies from one propagation geometry to another due to the anisotropy of the substrate. It governs pulse shape evolution in homogeneous halfspaces and the shapes of solitary surface pulses that exist in coated substrates. The theory describing nonlinear Rayleigh-type surface acoustic waves is extended in a straightforward way to surface waves that are localized at a one-dimensional acoustic waveguide like elastic wedges.
给出了表面声波脉冲在受非线性影响的各向异性弹性介质中传播的理论描述。基于非线性弹性理论，给出了与声脉冲相关的表面斜率或纵向表面速度的演化方程。它包含一个非局部非线性，其特征在于一个核，由于基底的各向异性，该核在不同的传播几何结构之间有很大变化。它控制均匀半空间中脉冲形状的演化以及涂层基底中存在的孤立表面脉冲的形状。描述非线性瑞利型表面声波的理论以直接的方式扩展到局限于一维声波导（如弹性楔）的表面波。
