共查询到19条相似文献,搜索用时 62 毫秒
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饱和土层中Love波的传播特性 总被引:1,自引:0,他引:1
基于Biot的液体饱和孔隙介质模型,考虑孔隙流体粘性,导出了弹性半空间上饱和土层中Love波的复频散方程,然后将其转化为两个实方程并利用迭代的方法进行求解。讨论了Love波的波速范围、Love波的频散和衰减特性以及Love波的位移分布。 相似文献
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饱和土中Love波弥散特性 总被引:4,自引:0,他引:4
本文利用有限元法推导了饱和土中Love面波的弥散特性方程,讨论了饱和土中Love面波波速度的弥散特性及位移分布规律,并与相应弹性地基Love面波的波速度弥散曲线进行了比较。 相似文献
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利用有限元法及解析法相结合的方法建立了地基含有倾斜层时Love波弥散特征方程和位移计算公式,利用这一方法研究了该类地基Love波弥散特性,并与水平成层地基进行比较。 相似文献
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利用短周期地脉动推断深层地基S波速度 总被引:3,自引:0,他引:3
从二维随机波场的相关理论出发,提出了如何从短周期地脉动(频率>0.5Hz)时域信号中计算Rayleigh波弥散曲线,进而反演深层地基剪切波(S波)速度的理论方法和分析技术,并结合实测信号的分析结果,探讨了该方法的可行性和实用性。 相似文献
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用Love面波特性计算动力响应的进一步探讨 总被引:2,自引:1,他引:1
根据上软下硬地基中Love面波的能流分布规律,提出了利用Love面波的第一模态波模拟水平方向传播波,而竖直方向传播波则采用半无限单元来模拟。通过算例来验证本文方法的可靠性和精确性,并讨论了传统的传递边界法的可靠性,对这两种方法进行了比较。最后讨论了衰减系数φ对计算结果的灵敏性。 相似文献
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非饱和地基中Love波的传播特性 总被引:1,自引:0,他引:1
基于非饱和多孔介质的波动方程,考虑了土中水,气体与土骨架之间的粘性耦合作用,建立了弹性半空间上非饱和土层中Love波的弥散方程。首先分析了饱和度与频率对非饱和孔隙介质中剪切波速的影响。然后运用数值方法得到了不同饱和度下土层中多种Love模态波的弥散特性和位移分布情况,并用图表的形式给出。数值计算结果表明,上覆非饱和土层中Love波的传播速度和衰减系数不仅具有频散性,而且与土层的饱和度有关。在不同饱和度时的高模态(n≥2)的Love波的截止频率值不同。此外,讨论了饱和度对Love波水平位移幅值的影响。 相似文献
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以金属醇盐乙酸钾[K(OC2H5)],乙醇铌[Nb(OC2H5)5]和乙醇钽[Ta(OC2H5)5]为原料,用Sol-Gel法合成了K(Ta,Nb)O3超细粉末和薄膜,研究了工艺参数如前驱体溶液浓度、热处理温度等因素对材料结构及物性的影响.粉料的粒径为20~40nm,所需合成温度约为700℃,比通过传统的固相反应制备同种材料的合成温度低近100℃;以SrTiO3(100)单晶作基片,采用匀胶法获得了沿(100)高取向生长的K(Ta0.65Nb0.35)O3薄膜,薄膜表面均匀、致密,室温时呈立方相晶格结构.研究表明,选择物理性质相似、晶格常数相匹配的材料作基片,适当控制工艺参数,尤其是前驱体溶液的浓度、升降温速度及烧结温度是获得优质薄膜的关键. 相似文献
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Journal of Engineering Physics and Thermophysics - Equations and relations have been obtained for describing one-dimensional filtration waves in a homogeneous isotropic porous medium in plane,... 相似文献
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Chiang C. Mei 《Journal of Engineering Mathematics》1999,35(1-2):43-57
The mild-slope approximation has become a popular basis for calculating infinitesimal surface waves on slowly varying depth. It is less restrictive hence more advantageous than the ray and parabolic approximations for describing diffraction and refraction by bathymetry and/or by complex coastlines. Since its computation involves only two horizontal coordinates, the mild-slope equation is also numerically less demanding than the solution of fully three- dimensional equations for a horizontal area with sides much greater than the typical wavelength. By consideration of nonlinear effects of the second order, the mild-slope approximation for long waves over slowly varying depth is derived here, in order to provide a convenient basis for predicting long-period resonance in a large harbor by short-period wind waves. 相似文献
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Genady P. Cherepanov 《International Journal of Fracture》2009,159(1):81-84
Self-sustaining fracture waves hypothesized by Galin and Cherepanov (1966) have been observed in shock-compressed glasses
and in Prince Rupert’s drops, but their speed did not correspond to the predicted value. This controversy is addressed in
the present note. We now assume that this speed is equal to the local velocity of sound in the particulate material just behind
the wave front, and show that, then, it is in a reasonable agreement with test data. The specific heat spent on the self-sustaining
fracture wave in soda lime glass is estimated to be 1 to 20 J/g for moderately high pressures. 相似文献
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脉冲波和阶跃波输入的产品破损边界 总被引:1,自引:1,他引:0
以产品包装破损极限理论为基础,以有限上升阶跃波为例,对阶跃波和脉冲波作用下的产品破损边界曲线进行了求解,并对其进行了系统的分析和比较. 相似文献
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A simple idea for self-focusing of a linear array has been extended to Rayleigh and Lamb waves. The self-focusing procedure
first measures the backscattered signals for a first transmission by a single element of the array. A cross-correlation technique
is used to determine the time-of-flight differences of the backscattered signals received by the elements of the array. These
time delays are used to adjust the times of excitation of the elements for transmission focusing on the defect. Using the
differences in arrival time once more, the backscattered signals after transmission focusing are aligned for reception focusing.
Experimental results demonstrate the ability to self-focus on single defects. For multiple defects, the technique has been
extended to focus on the defect that produces the largest backscattered signal. 相似文献
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B. M. Berkovskii V. G. Bashtovoi 《Journal of Engineering Physics and Thermophysics》1970,18(5):629-632
It is shown that in viscous heat conductive ferromagnetic liquids with infinite conductivity under definite thermal conditions, slightly damped and undamped temperature and magneto-hydrodynamic waves are propagated. The lengths and frequencies of the undamped waves are found. The physical mechanism of their excitation is discussed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 18, No. 5, pp. 899–904, May, 1970. 相似文献