Model parameters of the nonlinear stiffness of the vibrator-ground contact determined by inversion of vibrator accelerometer data
Model parameters of the nonlinear stiffness of the vibrator-ground contact determined by inversion of vibrator accelerometer data
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DOI：
10.1190/1.2196870
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发表时间：
2006-05
期刊：
影响因子：
3.3
通讯作者：
A. V. Lebedev;I. Beresnev;P. Vermeer
中科院分区：
文献类型：
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作者：
A. V. Lebedev;I. Beresnev;P. Vermeer
对可控震源数据的分析表明，地力信号中的谐波失真可能会超过液压系统的主要失真。这可以用接触粗糙度的变形产生的基板-地面接触非线性来解释。我们将液压系统中产生的非线性失真与接触时产生的非线性失真分开。然后，基于非线性源的等效模型以及预测和观测的谐波水平的比较，我们建立了求解非线性接触刚度参数的反问题。利用在砂土上获得的数据，对双线性接触模型和刚度在两个渐近值之间平滑变化的接触模型进行了反问题求解。两种模型的刚度在压缩时约为10 9N/m，拉伸时约为6 10 8N/m，虽然光滑的非线性-刚性模型是更好的近似。分析表明，等效力学源模型用于描述实际土基耦合系统中的非线性变形是充分的。
Analysis of vibroseis data shows that harmonic distortion in the ground-force signal may exceed the primary distortions in the hydraulic system. This can be explained by the baseplate-ground contact nonlinearity created by the deformations of the contact roughness. We separated the nonlinear distortion generated in the hydraulics from that generated at the contact. We then formulated an inverse problem for resolving the parameters of the nonlinear contact rigidity, based on the equivalent model of the nonlinear source and the comparison of predicted and observed harmonic levels. The inverse problem was solved for models of bilinear contact and the contact with the rigidity smoothly varying between two asymptotic values, using data obtained on sandy soil. Rigidities changing between approximately 10 9 N/m in compression and 6 10 8 N/m in tension were resolved from the inversion for both models, although the smooth nonlinear-rigidity model is a better approximation. The analysis shows the adequacy of the equivalent mechanical source model used for the description of nolinear distortions in real soil-baseplate coupled systems.