面波法与单孔检层法波速测试的工程应用

简述了面波法与单孔法等波速测试方法的工作原理、现场施测技术以及数据处理和资料分析过程.以工程实例说明了波速测试技术在岩土工程勘察设计中的应用及其效果.最后就勘探工作的总体安排及其原位测试方法的选择进行了探讨.     

德布罗意波波速佯谬分析

德布罗意波波速佯谬的谬点不是群速、相速问题，而是能量形式的混淆。微观粒子不是波包，不能用波包的群速和相速描述粒子的运动速度。     

Inverse method for the determination of elastic properties of coating layers by the surface ultrasonic waves

INTRODUCTION The elastic properties of coating layers in coating materials are very important in the design and evaluation for engineering purpose. They can serve as ground knowledge in the selection of surface coatings for particular applications, and can be used to monitor the quality of physical processes (Every, 2002). Therefore, estimation of the elastic properties of coating layers is of great practical value. Much effort has been put into measuring the material properties of coatin…     

砂土地震液化的不确定性判别法综述

通过对不同自由场地液化势估计的方法和公式进行总结和比较 ,发现剪切波速比其它波的波速更能反映地基岩土层的工作性能 ,现已为全国地基勘察规范所采用     

全反射时的表面波特性

本文讨论了全反射时的表面现象,从表面波的透入深度、相速、波长以及能流等方面论述了表面皮的特性;从而说明表面波虽亦是进入光疏介质中的波场,但跟进入光疏介质中的折射波有着完全不同的性质。最后得到的结论是只有当入射角大于临界角时才有表面波存在,但在入射角等于临界角时,在光疏介质界面上所存在的波场并非表面波。     

多种测试方法在检测强夯加固效果中的应用

强夯加固效果用单一的检测方法往往难以完全准确判定。利用超重型动力触探、静载荷试验、多道瞬态瑞利测试三种方法,根据试验结果进行对比分析,最后选择多道瞬态瑞利波法可以快速、经济取得全方位的检测效果,为后续及同类工程提供类比经验。     

Numerical Simulation of Surface Acoustic Wave and Detection of Surface Crack in Steel

The surface acoustic wave (SAW) propagating in a sample of steel is simulated by using finite element method (FEM). The waves are excited by a load function with propagation properties such as phase velocity dispersion and wide bandwidth. A two-dimensional model consisting of surface defects loaded with a wideband 50-200 MHz and short time 0.1 μs displacement function is investigated in the time and frequency domains. By transient dynamic analysis, Fourier transform and dispersion calculation, snapshots of propagating wave and responses from sensing points are presented. It is indicated that this supervision approach is sensitive to the surface cracks and reflections.     

隧道掌子面积水对瑞利波勘探影响研究

在使用瑞利波对隧道进行地质超前预报时,经常会遇到掌子面积水的情况。文章从分析瑞利波的波动方程入手,将掌子面积水假定为自由面上覆盖一层非弹性覆盖层,以此为基础推导出积水对瑞利波传播的影响方程,认为掌子面积水情况下,受到垂直应力的作用瑞利波发生频散,同时岩体质子的振动也会由于外界水体的存在而受到黏滞力的影响,瑞利波周期变大、频率变小。但是经过深入研究和结合工程实例,发现这种影响仅仅停留在积水层表面,对整个工程地质超前预报没有明显影响。     

超声波传播速度与溶液浓度关系的研究

利用超声光栅测量声速原理,针对不同浓度的食盐（NaCl）和葡萄糖（C2H12Q6）溶液,详细研究了超声波声速与溶液浓度的关系。实验结果表明,由0％至饱和范困．声速随浓度的增加单调递增,并显现出良好的线性关系。通过规划分析,得到25℃下声速与浓度的线性规划方程。溶液浓度每升高1％,超声波在食盐溶液中的传播速度提高10．777m／s．在葡萄糖溶液中的传播速度提高3．1863m／s。论文将线性回归方法应用于超声光栅实验数据处理,并且提出了一种测量液体浓度的新方法。     

De Broglie Wave的相速度和群速度

De Broglie Wave是可以按照几率解释的,在几率解释的基础上研究De Broglie Wave的相速度、群速度等速度特性,并建立了它们的关系。     

Comprehensive study on the results of tension leg platform responses in random sea

INTRODUCTION There is obvious demand for oil exploitation in deep water. Increasing water depth will make the environment more severe and so some innovative structures are required for economic production of gas and petroleum in deep water. An engineering idea is the minimization of the structure resistance to en-vironmental loads by making the structure flexible. This structural flexibility causes nonlinearity in the structural stiffness matrix because of large deforma-tions. Wave loadi…     

弹性波在声子晶体中的带结构

本文用平面波方法,研究了Pb圆柱体在epoxy基体中按周期性排列时的弹性波带结构,研究发现弹性波在将质量密度较大的介质柱嵌入质量密度较小的基体构成的声子晶体中将有完全带隙出现.     

论群速相速概念与电磁波传播模式

文章研究了电磁波传播的群速与相速概念，论证了信号传送与能量传递的必然联系。研究了波导模式理论与单模传播条件，电磁波在等离子体中传播时的信号传送速度，并讨论了传输线的色散问题。     

混凝土冻融耐久性的试验研究

以混凝土冻融耐久性为研究内容，用不同种类混凝土的抗压强度、动弹性模量、超声波声速等指标的损失率来表征冻融过程中混凝土的性能劣化状况，并系统比较了不同种类混凝土的抗冻性优劣．通过研究得出：无论是普通混凝土，还是高强混凝土或高性能混凝土，其动弹模损失率、抗压强度损失率、超声波声速损失率均随冻融次数的增加而增大；提高混凝土强度在一定程度上可以提高混凝土抗冻融性能；掺入高效减水剂、优质引气剂和优质掺合料等，高性能混凝土抗冻融性能比对应的基准混凝土性能显著改善，而且通过这样的技术措施，较低强度等级的混凝土也可以获得高抗冻性．鉴于超声波测试方法方便、快捷、准确。而且可以直接用于实际工程的混凝土性能检测，所以，与动弹模测试方法相比，采用超声波测试技术来评价实际工程中混凝土的耐久性劣化程度具有明显的优势．     

波动曲线中几个量的判断

根据波动曲线来判断介质质点振动的位移和速度的正负以及位相或位相所在象限。     

Excitation of axisymmetric and non-axisymmetric guided waves in elastic hollow cylinders by magnetostrictive transducers

Ultrasonic guided waves have been successfully applied in nondestructive evaluation (NDE) and structural health monitoring (SHM) of pressure vessels and pipelines due to their advantages, such as long detection range and high inspection efficiency. Compared with other ultrasonic guided wave actuators, magnetostrictive transducers are more cost-effective, involve simpler fabrication process, and have higher possible transduction efficiency. The normal mode expansion (NME) method is adopted to analyze the forced response and perturbation analysis of elastic hollow cylinders with respect to magnetostrictive loadings, including partial loading, axial array loading, and circular array loading. The phase velocity and frequency spectra of axisymmetric/non-axisymmetric guided waves excited by magnetostrictive transducers are analyzed. The theoretically predicted trends are verified by finite element numerical simulations and experiments.     

超声光栅研究声速与溶液浓度及温度的关系

根据超声光栅测量声速的原理,使用超声光栅声速仪测量并计算出超声波在不同浓度和温度条件下该溶液中的传播速度.通过对比不同浓度、不同温度的NaC1溶液中的声速并对其进行数据拟合,得出声速与溶液浓度、声速与溶液温度的关系.实验结果表明,在相同温度,浓度3％ ～15％,声速随溶液浓度的增加而增加,并显现出良好的线性关系;利用温度递增研究了3％ NaCl溶液和清水中超声传播的速度,声速与温度显现出良好的线性关系,声速随液体温度的增加而递增.     

多普勒效应教学研究

在多普勒效应教学中，利用波源与观察者之间的相对运动，对波源和观察者建立不同的坐标系，写出不同坐标系波函数的表达式；根据波传播过程中在两个坐标系中有相同的相位，分析导出多普勒效应，并引伸至相对论下的多普勒效应。     

Surface-mounted bender elements for measuring horizontal shear wave velocity of soils

The bender element testing features its in-plane directivity, which allows using bender elements to measure the shear wave velocities in a wider range of in-plane configurations besides the standard tip-to-tip alignment. This paper proposed a novel bender element testing technique for measuring the horizontal shear wave velocity of soils, where the bender elements are surface- mounted and the axes of the source and receiver elements are parallel to each other. The preliminary tests performed on model ground of silica sand showed that, by properly determining the travel distance and time of the shear waves, the surface-mounted bender elements can perform as accurately as the conventional ＂tip-to-tip＂ configuration. Potentially, the present system provides a promising nondestructive tool for characterizing geomaterials and site conditions both in laboratory and in the fields.     

玻璃钢复合材料板材Lamb波传播特性分析

基于Lamb波在各向异性材料的波动方程和频散原理,采用斜入射法激发A0模态兰姆波。针对板材的铺层角度、各接收点方向和频厚积等因素对衰减规律和传播速度规律有较大影响,采用有限元软件建立玻璃钢复合材料层合板模型,对各影响因素进行数值模拟研究。研究表明:Lamb波传播特性与纤维铺层方式有关,声速及衰减特性沿纤维方向和非纤维方向传播声速和衰减差异较大,并且呈对称现象,频厚积在0.6~1.8 MHz·mm,对传播声速和衰减影响为线性下降且趋于平稳。