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。

There were the same load characteristics of 1MW, 1.5MW and 2MW blade model, which the tensile stress, shear stress and torque of section were linearly increased with increasing of wind speed; and tensile stress of all test sections of the blade was changed greatly, but shear stress was basically the same in the same wind speed. The shear stress and tensile stress were increased obviously in the place of 388mm to centre of gyration of wind rotor comparing with other section where the phenomenon of stress concentration had for 1.5MW blade model.

对1MW、1.5MW、2MW叶片模型有相同载荷特性，各截面处的拉应力、剪应力、扭矩随风速增大而增大，呈线性增加规律；在相同风速下，叶片各测试截面的拉应力值变化较大，而剪应力值基本相同，但对1.5MW叶片模型，在距风轮回转中心388mm处与其它截面处的剪应力、拉应力比较明显增大，有应力集中现象。

Based on the conception of the equivalent stress,the expressions of the equivalent stress was educed. In this optimal design, the macro file for calculating the equivalent stress of arch dam is complied by using the parameter design language of the software, and the optimal design for shape of arch dam using equivalent stress as stress restraint condition is carried out.

本文基于等效应力概念，推导了拱坝有限元等效应力计算公式，将有限元法求得的坝体与基岩交接面上的应力合成截面内力，然后求出对应的线性化应力，并以此应力作为应力约束条件，实现了以等效应力作为应力约束条件进行拱坝体形优化。

The three groups were loaded and analyzed under the same loading according to the mean value of the bite force of incisors. RESULTS:(1)The maximum stress of dentin in group A was twice higher than that in group B. The maximum primary stress, minimum primary stress and maximum shear stress of group A were respectively 236.35, 228.83 and 218.05 percent of those in group B. The difference of maximum stress values of group B and group C was neglectable.(2) The maximum stress distribution of dentin in group A and group B was quite different (the stress was concentrated in labial and lingual side of the cervical dentin in group A, otherwise in group B it was concentrated in the area around the alveolar and the labial and lingual side of the dentin which was opposite to the tip of the cast metal post and core). The maximum stress distribution of dentin in group A and group B was almost the same.

结果：(1)从牙本质的应力大小来看，A组中牙本质最大应力值比B组中牙本质最大应力值增大了1倍以上（最大主应力、最小主应力和最大剪切应力A组分别是B组的236.35%、228.83%和218.05%），而B组与C组的牙本质最大应力值相差极小；(2)从牙本质的应力分布位置来看，A组与B组的牙本质最大应力分布位置相差甚远（A组主要集中在牙颈部唇舌侧肩台部的牙本质上，B组主要集中于牙槽嵴顶附近及铸造桩核尾端相对应的唇舌侧的牙本质上），而B组与C组的牙本质最大应力分布几乎在同一位置。

The plastic deformation induced due to cyclic rotation of principal stress axes alone can be in the same magnitude as that due to shear with fixed principal stress axes. 2 The volumetric strain due to shearing of cyclic rotation of principal stress axes is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. The former is characterized by its reversibility and is independent of past shear history, the latter by its irreversibility increases with the increase of cycle number yet its increase rate decreases with its accumulation. 3 The obvious non-coaxiality between directions of the principal stresses and principal strain increments is found and its degree depends largely on the change of shear stress component. 4 The intermediate principal stress has considerable effects on the deformation behavior of sands in the condition of cyclic rotation of principal stress axes. The accumulation rate of the irreversible dilatancy component increases with the increase of the intermediate principal stress parameter.

具有初始各向异性的砂土在纯应力主轴循环旋转排水条件下的主要变形规律为：①纯应力主轴循环旋转可产生与应力主轴固定单调剪切处于同一数量级的塑性变形；②纯应力主轴循环旋转引起的剪切体变包含可逆性剪切体变分量和不可逆性剪切体变分量两部分，其中可逆性剪切体变分量在一周内可完全恢复，基本与应力历史无关；不可逆性剪切体变分量随循环周数的增加呈单调增加，且增加速率随其自身累积值的增大呈减小趋势；③应变增量主轴与应力主轴之间的非共轴现象显著，且在一周内具有分段性；④中主应力对应力主轴循环旋转条件下砂土的变形特性有重要影响，不可逆性剪切体变分量的累积速率随中主应力系数的增加而增加。

First, this article introduced 2 grade of rotary kiln principle of work and the equipment, to rolled the circle mechanics behavior to carry on the analysis, proposed - rolled the circle - under roller's rotary kiln overall modelling based on the tube body - kiln liner - big tooth ring, to rolled the circle - under roller's contact stress to carry on the finite element analysis the method, and obtained rolled the circle contact stress the size and the distribution rule, finally indicated that rolled the circle contact stress mainly to have two main peak values and the sudden change in one week, appeared is rolling the circle and the under roller contact area; Then, rolls the circle the stress to regard as is the principal stress unknown plane stress test, the use quite mature modern test technology, proposed rolls the circle stress test the principle and the plan, and to rolled the circle the stress to carry on the scene test, the stress which the scene test analysis result and the finite element analysis calculated has compared, had proven the whole method modelling's finite element analysis method's rationality and rolled the circle - under roller contact stress the result accuracy; Finally, uses ANSYS APDL the re-development technology, in view of 2 grades of rotary kilns, rolled the circle - under roller contact stress the overall finite element analytic method to carry on the re-development.

首先，本文介绍了2档回转窑工作原理和装置，对滚圈的力学行为进行了分析，提出了基于筒体-窑衬-大齿圈-滚圈-托轮的回转窑整体建模，对滚圈-托轮的接触应力进行有限元分析的方法，并得到了滚圈接触应力的大小和分布规律，结果表明滚圈接触应力在一周内主要存在两个主要的峰值和突变，都出现在滚圈与托轮接触区域；然后，把滚圈的受力看成是主应力未知的平面应力的测试，利用比较成熟的现代测试技术，提出了滚圈应力测试的原理和方案，并对滚圈的应力进行了现场测试，现场测试分析结果与有限元分析计算出的应力相比较，证明了整体法建模的有限元分析方法的合理性和滚圈-托轮接触应力的结果的正确性；最后，利用ANSYS的APDL的二次开发技术，针对2档回转窑，就滚圈-托轮接触应力的整体有限元分析法进行了二次开发。

Firstly, the paper introduced the working principle and device of the two-pass grate-rotary kiln and had an analysis method of mechanics of the tyre. We have put forward the finite element analysis of the contact stress of the tyre-roller based on the whole construction mode of shell-kiln liner-large gear-tyre-roller of the rotary kiln and obtained the strength and distributing rule of the tyre's contact stress. The research shows that within one week the contact stress mainly lies in two leading peak value and catastrophe which appear at the contact zone of the tyre and supporting roller. Then we regarded the tyre's stress as the test of unknown plane stress of principal stress. Utilizing mature and modern testing technology, we raised the testing principle and scheme of tyre stress and then had a on-the-spot test of the stress. Comparing the analysis result of the test with the one calculated from the finite element analysis, it proofed the rationality of finite element analysis method of integral modeling and the correctness of the contact stress result of the tyre and roller. Finally, for two-pass of similar rotary kilns, using the ANSYS APDL re-development technology, carried on the re-development about the overall finite element analytic method of thecontact stress of tyre-roller.

首先，本文介绍了2档回转窑的工作原理和装置，对滚圈的力学行为进行了分析，提出了基于筒体-滚圈-托轮的回转窑整体建模的有限元分析法，来对滚圈-托轮的接触应力进行有限元分析与计算，得到了滚圈接触应力的大小和分布规律，并求得滚圈外中内圈节点的主应力；其次，把滚圈的受力看成是主应力未知的平面应力的测试，利用现代测试技术，提出了滚圈主应力测试的原理和方案，并对滚圈的主应力进行了现场测试，现场测试分析结果与有限元分析计算出的主应力相比较，证明了整体法建模的有限元分析方法的合理性和滚圈-托轮接触应力结果的正确性；最后，利用ANSYS的APDL的二次开发技术，针对2档同类回转窑，就滚圈-托轮接触应力的整体有限元分析法进行了二次开发。

It is the macro effect of accumulative micro fracture in all period of time that spallation failure is induced by reflection of stress wave emerges.

研究结果表明：应力波延续时间和应力幅值对岩石的层裂过程影响较大，不同形状的应力波实际上是在相同时段内应力波具有不同的应力幅值和不同的应力加载速率，不同形状的应力波对介质的作用结果是这些因素同时作用的综合反映；应力波反射诱发层裂过程的发生，是各个时刻不同加载条件下微破裂累积的宏观体现。

Results: Before the fixed bridge was applied, under vertical load, the high-stress region was near around the apical of periodontal ligament with mainly compressive stresses. Under oblique load, the high-stress region was near around the cervical of periodontal ligament with both tensile and compressive stresses. After the fixed prosthodontics, stress and strain distributions were similar with that when the fixed bridge was not applied. But the maximum stress, strain and displacement increased apparently. The stresses in exterior surface of periodontal ligament were larger than that of interior surface; this character of periodontal ligament under vertical load was more obvious than that under oblique load.

结果：固定桥修复前，垂直载荷下，基牙牙周膜的应力以压应力为主，应力集中在根尖；斜向载荷下，基牙牙周膜的应力主要是拉应力和压应力，应力集中在唇、舌颈缘；固定桥修复后，基牙牙周膜的应力和应变分布规律与修复前相似，但最大应力、应变值都明显增大；牙周膜内表面的应力大于牙周膜外表面；垂直载荷时，牙周膜内、外表面的应力差异更为显著。

The main research tasks and results are as follows:(1) Through comparing the stress intensity factor of compact tension specimen calculated by finite element software with the theoretical value, the feasibility of calculating fracture parameters of crack tip in ABAQUS software was verified.(2) The relationship between the elastic modulus of the material and research scale was studied based on deriving the cohesive stress theory and other relevant theories. And the elastic modulus of the material on meso-scale was determined.(3) Global model and sub-model of the finite element were built in th...e macro-scale, and stress-strain field nearby the crack tip was analyzed, and the results show that the detailed stress-strain in the crack tip could be obtained by using the sub-model technique.(4) In meso-scale, the crack growth model was also established by assuming the crack propagating along the grain boundary, and the detailed stress-strain field in the crack tip was obtained.(5) The effect of crack length on Von Mises stress, and maximum principal stress and strain was analyzed in meso-scale when equivalent KI equals 30MPa.m1/2. And the results show that except for crack tip area, the stress-strain distribution in whole specimen is not affected.

主要完成研究内容和取得成果如下：(1)利用有限元软件计算出紧凑拉伸试样的裂纹尖端应力强度因子KI值，其结果与理论值一致，从而验证了利用ABAQUS计算裂纹尖端相关断裂参量的可行性；(2)在研究内聚应力等相关理论的基础上，推导出了研究尺度与材料弹性模量的近似关系，并确定了介观尺度上的弹性模量；(3)在宏观尺度上建立了全局有限元计算模型和子模型，得到了裂纹尖端应力应变场分布，结果表明利用子模型技术获得比较准确的裂纹尖端应力应变场分布是可行的；(4)在介观尺度上利用平均晶粒尺度的方式建立了裂纹沿晶扩展模型，得到了裂纹尖端断裂过程区的微观应力应变场；(5)当应力强度因子为30MPa.m1/2时，分析了介观尺度上在裂纹沿晶扩展过程中裂纹长度对Mises应力、最大主应力和应变的影响，结果表明，裂纹扩展长度对试样整体应力应变分布影响不大，而对裂纹尖端区域有较大影响；(6)介。。。

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。