查询词典 shear stress

The main factors affecting the soil-structure interface behaviors were found experimentally and theoretically, including: 1 the thickness of the interface that is five to six times the average grain size of the soil; 2 the aeolotropy of interface, which is responsible for anisotropic response of the stress-strain response of the interface; 3 two physical states, including crashing and compression of the soil near the structure surface, which govern the stress-strain response of the interface strongly; 4 two shear deformation components due to sliding and constraint of the structure surface relative to the soil respectively, which forms the deformation of the interface; 5 the volumetric strain due to dilatancy, which is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. 4. A unified constitutive model of the interface, based on new elasto-plasticity damage theory, was developed. It was confirmed to be effective for the conditions considering monotonic and cyclic shearing, coupling effect of shear and volumetric strains, evolution of physical state, micro-structure aeolotropy of the soil and the resulting aeolotropy of the interface as well as the three normal boundary conditions stated above. 5. 2D and 3D finite element formulations of the present model were derived and incorporated into the FEM codes. They were applied to the evaluation of practical engineering problems with different typical interfaces between soil and structure. The new model was shown to be reasonable and effective.

确定了粗粒土与结构接触面厚度约为5～6倍的平均粒径，首次揭示了接触面的细观结构异向性以及由此所引起的宏观剪切异向性，发现了在单调和往返剪切荷载作用下土颗粒破碎和剪切压密两种物态变化机制共同支配着接触面力学性质的变化，通过细观分析证实了接触面的变形可分解为一般同时发生的土与结构交界面上的滑移变形以及结构面位移约束范围之内土体本身的剪切变形两部分，观测到接触面受剪时表现出明显的相对法向位移，并可分解为可逆性和不可逆性两个分量；(4)建立了第一个能够统一地描述单调与往返剪切特性、剪应变与体应变耦合特性、细观结构和宏观剪切异向性以及土颗粒破碎等物态变化特性的土与结构接触面弹塑性损伤本构数学模型，并采用多种法向边界条件复杂加载路径的试验成果验证了新模型的合理性和有效性；(5)提出了新模型的二、三维有限元格式并结合实际边值问题进行了应用计算分析，比较了不同接触面本构模型对计算结果的影响，证实了新模型及其有限元格式不仅能够合理地描述土与结构接触面的主要力学特性，还能够较好地反映土体与结构物在接触面处的滑移、脱开等不连续现象。

It is shown that the mechanical properties including Young's modulus, tensile strength, critical strain and stress under buckling can be enhanced with the decreasing of intershell spacing. The shear strength can be enhanced by 2-3 orders of magnitude when the intershell spacing is reduced to 20%, which is also dependent on commensuration. Zigzag-type carbon nanotubes have higher shear strength. The axial stress in tubes when the load transferring from outmost tube to inner tube is observed as well.

研究了单壁纳米管束横截面的六方化失稳现象，给出各种管径的面内压力－应变关系曲线；每条曲线都给出一个明显的拐点而且有很强的非线性；线弹性模量与参考构形有关，也受管直径的影响；分析了管束横截面的晶格不稳定性特征，表明晶格的缺陷能够明显的减小临界值；模拟了在不同应变下纳米管束对静水压的反应，发现不同压力下的截面形态不同，在很高压力下相邻管之间会形成化学键。

Concretely, firstly with Timoshenko beams, the fundamental formulae of solutions of dynamical equations, boundary conditions and initial conditions have been transformed by Laplace transformation. Secondly, in the Laplace regions , we gain the analytical solutions of impact forces at the impact contact points, shear and maximum inverse stress of beams. Then, by using Durbin numerical inverse method, we gain the numerical solutions of Timoshenko beams under various restriction conditions. Moreover, the graphs about impact forces at the impact contact points, shear and maximum inverse stress of beams can be obtained too.

把Timoshenko梁力学模型动力学方程的基本解形式、边界条件以及初始条件进行Laplace变换，在Laplace区域得到了冲击接触处的冲击力、整个梁的最大弯曲应力和剪力的解析解，然后利用Durbin数值反演的方法得到了各种约束条件下的Timoshenko梁模型时间-空间的数值解，得到了冲击接触处的冲击力、梁各处的最大弯曲应力和剪力的曲线图。

At the same time, under the condition of small strain, firstly, the secant shear modulus was always larger than the tangent shear modulus. Secondly, when the logarithmic coordinates were applied to describe shear strain, the decrease of shear modulus with shear strain could be expressed by reversed S shape curve with two inflexion points, and through analyzing and validating, the deduced equation could perfectly reflect this characteristic. Finally, different stress paths and strain areas would lead to different attenuation trends.

而且，在小应变范围内，割线剪切模量总是大于切线剪切模量；当剪切应变采用对数坐标表示时，剪切模量随着剪切应变的增加而衰减，且衰减的规律都可以表示为带有两个拐点的反S型曲线，经分析验证本文所得公式3可以对此特性进行很好地反映；但应力路径、应变范围不同其衰减幅度不同。

The soil static and dynamic universal triaxial and torsional shear apparatus which can simulate the cyclic stress characteristic of sand on seabed is used to perform experimental tests of loose carbonate sand s with a relative density of 30% subjected to vertical-and-torsional coupling cyclic shear with the rotation of principal stress axes induced by ocean wave.

利用土工静力-动力液压三轴-扭剪多功能剪切仪模拟海洋波浪的加载形式，对相对密度为30%的钙质砂进行了扭转和竖向耦合循环剪切试验，着重研究了复杂应力状态下初始主应力方向角α0和中主应力系数b对钙质砂动强度特性的影响。

Such a diagram will show a definite straight-line portionin which the shearing stress is directly proportional to the shearing strain, Like the normal stress-strain ratio, the ratio of the two shear quantities, is known as the modulus rigidity or shear modulus of elasticity.

这个图表中的直线部分明确表示出剪切应力与其产生的相应的剪切应变。象常规的应力应变比值一样，此两者剪切量之间的比值，被称为弹性剪切模量或者硬度系数。

Similarly, if the strong shear, which could suppress all the scattering in the quiescent two phase region, stopped, the follow-up phase separation also displayed characteristics of anisotropism and relaxation, In this dissertation, the transposed"butterfly'and"streakpattern were observed for the first time within the shear-history-influenced phase separation, which is found closely relevant to the anisotropical relaxation behavior of macromolecules. 5. The phase separation kinetics of PS/PVME under oscillatory shear was further studied on the base of that done under simple shear. It is found that, under specific temperature and strain amplitude, the occurrence of phase separation is strongly contingent on oscillatory frequency and only intermediate frequency could effectively induce phase separation; If all considered oscillatory shear could stimulate phase separation, a fixed frequency can maintain specific most probable phase size and higher frequency yields smaller phase, which makes a higher elasticity but weaker stress relaxation; Furthermore, higher frequency can produces stronger compulsory oscillation on the MPPS but won't change the mean of the MPPS. Under given frequency and strain amplitude, the phase separation kinetics dramatically depends on the phase angle of oscillation and the phase separation corresponding to different phase angle follows different dynamical process.

在简单剪切场下相分离动力学研究的基础上进一步对振动剪切场下PS／PVME的相分离动力力学进行了尝试性的研究，发现：在一定温度和振幅条件下，相分离的发生强烈的依赖于振动频率，只有中等频率的振动剪切才能有效地促进相分离的发生；在都能使相分离发生的前提下，一定频率的剪切能够使体系维持一定的最可几相尺寸，较高频率的剪切导致体系形成的相区尺寸较小，因而体系的弹性效应较强而应力松弛效应较弱；同时，更高频率的剪切对最可几相尺寸的强迫振动效应越强，但不会使最可几相尺寸的平均值发生改变；在一定的振幅和频率条件下，相分离的动力学过程会强烈地依赖于相位角，不同相位角对应的相分离遵循不同的动力学过程但机理一样。

Taking the remolded soil after K 0consolidation and the samples under special stress state by special stress path as the objects, the effect of stress path circumgyration on shear modulus and the trend of shear modulus along with strain under condition of small strain are studied.

以重塑土经K0固结形成的试样以及经K0固结后通过特殊应力路径达到特定应力状态的试样为对象，研究了在小应变范围内应力路径旋转对土体剪切模量的影响以及剪切模量随应变变化的趋势。

Under the condition of small strain, the initial value of shear modulus increased along with the increment of angle θ between trail stress paths and recent stress history. If the two directions were entirely reverse, the effect of stress path circumgyration on shear modulus was the largest; if they coincided completely, the effect was very feeble.

研究表明，在小应变范围内，剪切模量的初始值随试验应力路径与近期应力历史间的夹角θ的增大而增大，当两者完全相反时，应力路径旋转对土体在小应变条件下的剪切模量影响最大；完全一致时，其影响最弱。

Using high frequency induction brazing and TiZrNiCu filler metal, the shear strengths of the joints were low. The maximum shear strengh was only 102.1MPa, which was lower than the maximum strength of vacuum brazing. The reasons may be that excessive intermetallics, holes and oxidation existed in the joint. So TiZrNiCu filler metal isn't fit for non-vacuum brazing.The stress variation, stress distribution and crack-sensitive regions during the cooling process of brazing have been studied by Marc non-linear software.

采用气体保护高频感应加热、TiZrNiCu钎料钎焊时，接头的强度普遍偏低，最高的剪切强度只有102.1MPa，远远低于辐射加热真空钎焊的强度，其原因是接头中局部生成了过量的金属间化合物，且产生氧化，接头中含有较多的气孔等影响了接头强度，因此可以认为TiZrNiCu钎料不适合在非真空条件下的钎焊。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。