Observation of pulses on an interface
Observation of pulses on an interface
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观察界面上的脉冲
DOI：
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发表时间：
1962
期刊：
影响因子：
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通讯作者：
Richard Schell
中科院分区：
文献类型：
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作者：
F. Gilbert;S. Laster;M. Backus;Richard Schell
最近的理论结果表明，除了P和S脉冲外，在弹性固体的边界附近还可以定义两种类似脉冲的现象，记为P和S。S脉冲是Lamb 9 s问题中的经典Rayleigh脉冲，也是Cagniard 9 s问题中的经典Stoneley脉冲。当Stoneley存在条件被破坏时，对于许多固体对，S脉冲仍然存在，并且可以被视为辐射界面脉冲。P脉冲仅在σ（泊松比）大于约0.4时才是明显的。这似乎是S脉冲的对偶。这是Strick 9问题中的经典Stoneley脉冲。基斯林格在密苏里州的弗洛里森特附近的黄土和粘土中观测到了P脉冲。Pod 99 yapol 9 ski和Vassil 9 ev在粘土/花岗岩界面上观察到辐射S脉冲，Roever和Vining在流体/固体界面上观察到辐射S脉冲。Roever和Vining也可能观察到了音高上的P脉冲。对S脉冲的二维地震模型研究表明，它最容易从粒子轨道上识别出来。捕获和辐射S脉冲的模型结果与轨道运动和轨道倾斜的理论计算吻合得很好。Lamb 9问题中P轨道的倾斜实际上与弹性参数无关，P速度几乎是S速度的两倍。在色散问题中，辐射的P和S脉冲在色散曲线中都表现为扭结。
abstract Recent theoretical results show that, in addition to P and S pulses, two pulse-like phenomena, denoted by P and S , can be defined near the boundary of an elastic solid. The S pulse is the classic Rayleigh pulse in Lamb9s problem and is the classic Stoneley pulse in Cagniard9s problem. When the Stoneley existence conditions are violated, the S pulse still exists for many solid pairs and can be regarded as a radiating interface pulse. The P pulse is distinct only when σ (Poisson9s ratio) is greater than about 0.4. It seems to be the dual to the S pulse. It is the classic Stoneley pulse in Strick9s problem. The P pulse has been observed by Kisslinger in loess and clay near Florrisant, Missouri. The radiating S pulse has been observed by Pod99yapol9ski and Vassil9ev on a clay/granite interface, and by Roever and Vining on a fluid/solid interface. Roever and Vining may also have observed the P pulse on pitch. Two dimensional seismic model studies of the S pulse suggest that it is most easily recognized from its particle orbit. Model results for both the trapped and the radiating S pulse agree well with theoretical calculations of orbital motion and orbital tilt. The tilt of the P orbit in Lamb9s problem is virtually independent of the elastic parameters and the P velocity is very nearly twice the S velocity. In dispersion problems both radiating P and S pulses appear as kinks in the dispersion curves.