法向应力

Five main phenomena were found, firstly, the high plasticity clay could well suitable to large deformation, and had strain-hardening behavior obviously, as well as, the little dilatancy; secondly, there was no correlation between stress paths and shear strength but the stress-strain relations were influenced by stress paths; thirdly, the little stress increment ratio, the higher increase speeding of shear stress and breaking strength under the condition of same initial normal stress; the fourth, the relations between normal strain and normal stress in simple shear test was consistent with which in the single-direction compression test, if there was no dilatancy; the last, the curve of relation between stress ratio and shear strain could be well simulated by hyperbola.

试验结果表明，高塑性粘土能够较好地适应大变形，接触面剪应力与切向应变关系呈剪切硬化型曲线，法向剪胀不明显；接触面剪切强度与应力路径无关，应力应变关系与应力路径密切相关；初始法向应力一定，应力增量比越小，剪应力增长越快，对应的破坏剪应力也越高；无剪胀发生情况下，法向应变与法向应力关系曲线与单向压缩试验具有一致性；应力比与切向应变呈良好的双曲线关系。

A theoretical stress tensor model that includes surface tension forces and viscous forces is developed by considering the three-dimensional spatially periodic cells of dodecahedron. Meanwhile, the shear stress and normal stress difference under various shear rates are calculated by computer.

本文在同时考虑表面张力与粘性力的情况下，以三维模型—长菱形十二面体及泡沫的应力张量表达式为基础，得出了泡沫的剪应力及法向应力差表达式，并通过计算机进行了求解，讨论了泡沫粘度、泡沫大小等因素对剪应力及法向应力差的影响。

By solving a axial-symmetrical boundary value problem consisting of a infinite solid and an isolated spheriodal particle embedded in an infinite matrix, some interesting results are found as follow:(1) at the micron scale, the smaller the particle is, the higher the stresses at the matrix/inclusion interface and within the particle are;(2) this size effect is more remarkable with decreasing the stress triaxiality and increasing the remote equivalent strain.

通过对三轴应力下含椭球夹杂的无限大体边值问题的分析，结果表明：(1)在微米尺度下，夹杂尺寸越小，夹杂/基体界面的法向应力、剪切应力和夹杂内部主拉伸方向的应力越高。

In terms of continuum mechanics and nonequilibrium irreversible thermodynamics theories, compressible Leonov constitutive model is derived to describe large recoverable elastic strain development in non-isothermal flow of compressible viscoelastic melts. It is tempting to specify the model and then compare it to basic rheological tests in the hope that such a model will yield a good description of the nonlinear viscoelasticity of polymer melts.

注射成型是聚合物的主要成型加工方法之一，成型过程中聚合物要经历熔体流动和固化等非等温、非平衡过程，由于聚合物的粘弹性，流动过程中建立的剪切应力、法向应力和大弹性形变在固化过程中不能完全松弛，在制品中形成残余应力和取向，对制品的机械和光学性能有着重要影响。

The physical experiment on hydraulic fracturing propagation in laboratory showed that the penetration of hydraulic fracture into the salutatory barrier mainly depended on the normal stress difference between salutatory barrier and pay zone.

室内物理模拟实验研究发现，突变体法向应力对水力裂缝能否穿过突变体起着决定性作用，约4MPa的法向应力差可以促使水力裂缝穿透突变体，继续沿原来的方向延伸。

The monotonic and cyclic shear tests of the interface between geotextile and gravel as well as geotextile drawing tests were conducted with the apparatus. The interface was found to exhibit strain-softening and obvious aeolotropic normal displacement which was affected by the normal stress.

剪切试验结果表明，粗粒土与土工布接触面出现了一定程度的应变软化，相对法向位移的变化受法向应力影响很大，并表现出异向性。

The visco?-elastic fluid hydrodynamic theory was applied to the wear-resistance experiment on sucker rods.The values of normal stress in suck string generated by visco?-elastic fluid and eccentricity brought out by sucker string were measured quantitatively.The partial abrasion of sucker string and tube in oil well was caused from the normal stress of visco?-elastic fluid.A module for bending analysis of sucker rod in cross direction and wire direction was developed.

大庆油田实施聚合物驱油以后，出现了抽油杆受力状况恶化、抽油杆柱严重偏磨的现象，为此开展了粘弹性流体水动力学理论和试验研究，得出了粘弹性流体在抽油机井筒内的流动规律及对抽油杆柱法向应力的影响规律，定量测出了粘弹性流体对抽油杆柱的法向应力值和抽油杆柱产生的偏心率。

According to the stress characteristics of coal floor with faults, corresponding simplified mechanical model is built to obtain the equations of shear stress and normal stress on the fault, as well as the influential rules of fault dip on shear stress, normal stress and fault activation.

针对含断层缺陷底板的受力特征，建立相应的简化力学模型，分析得到断层面上的剪切应力和法向应力表达式，并研究断层倾角对断层面上剪切应力、法向应力及断层活化的影响规律。

After the result of cohesion-friction model is compared with Coulomb Criterion, it is found that when the results of shearing strength are many and adjacent the strength parameters can not be regressed by least square method, instead the results should be divided into some beelines at that time according to the cohesion-friction model.(4) Discuss the characters of hard structural plane and weak structural plane: The adhesive friction theory is applied to research the changing course of shear area of hard structural plane and its influence on shear stress.

3介绍了岩石强度理论中的粘接摩擦模型，运用此模型分析依附型滑动面的演化过程，并将其推广到边坡岩土体抗剪强度的选取，讨论了不同法向应力下峰值强度和残余强度随法向应力的变化规律，在此基础上给出抗剪强度的选取模式，讨论了对实际取值结果的影响，并与传统的Coulomb准则进行了比较分析，指出直剪试验的法向应力在小应力区的点较多且抗剪强度结果差异不大时，不宜直接运用最小二乘法回归抗剪强度参数，此时应结合粘接摩擦模型对结果进行线性分段。

Introduce the cohesion-friction model of rock strength theory, and extend the model to select the strength of sliding plane, discuss the variation rules of peak strength and residual strength under different normal stress, and then present the selection model of shearing strength. After the result of cohesion-friction model is compared with Coulomb Criterion, it is found that when the results of shearing strength are many and adjacent the strength parameters can not be regressed by least square method, instead the results should be divided into some beelines at that time according to the cohesion-friction model.(4) Discuss the characters of hard structural plane and weak structural plane: The adhesive friction theory is applied to research the changing course of shear area of hard structural plane and its influence on shear stress.

3介绍了岩石强度理论中的粘接摩擦模型，运用此模型分析依附型滑动面的演化过程，并将其推广到边坡岩土体抗剪强度的选取，讨论了不同法向应力下峰值强度和残余强度随法向应力的变化规律，在此基础上给出抗剪强度的选取模式，讨论了对实际取值结果的影响，并与传统的Coulomb准则进行了比较分析，指出直剪试验的法向应力在小应力区的点较多且抗剪强度结果差异不大时，不宜直接运用最小二乘法回归抗剪强度参数，此时应结合粘接摩擦模型对结果进行线性分段。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。