查询词典 compressive stress

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 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。。。

Analysis of the strain field discovers that the principal compressive and the principal tensile strain rates in the epicenter area are -30.840×10-9/a and 13.956×10-9/a respectively before earthquake, and the principal compressive strain axis is in a direction of N105.4°E which is consistent with the average direction at N107.5°E of the principal compressive stress axis from focal mechanism result.

应变场分析发现，震前震中区的主压与主张应变率分别为-30.840×10-9/a与13.956×10-9/a，主压应变轴N105.4°E与震源机制解得到的主压应力轴的方向N103°E一致。

In this paper, test research have been performed on the two important mechanical properties indicator compressive modulus of elasticity and shear modulus. Numerical simulation has been performed on the base of results of test under the situation uniform and uneven thickness of elastomer layer, which analyze internal stress distribution of the elastomeric bearing, as follows:(1) The traditional test methods of compressive modulus of elasticity test are rather cumbersome and take up experimentalists lots of time. This paper has improved the traditional test methods of compressive modulus of elasticity test, which has collected the holding-load time together to concentrate on holding load. The tests have been performed on different types of bearings, which results show that the results of the improved test method conform to the error range regulated by the standard and can effectively save time for the experimentalists, also eliminate the accumulative error.

本文主要对板式橡胶支座的抗压弹性模量、抗剪弹性模量两个重要力学性能指标进行试验研究，并在试验结果的基础上对均匀胶层厚度和不均匀胶层厚度两种情况进行数值模拟，分析橡胶支座内部应力分布规律，具体内容如下：(1)传统抗压弹性模量试验方法比较繁琐，占用试验人员大量时间，本文对传统抗压弹性模量试验方法进行了改进，将持荷时间集中起来进行集中持荷，通过对不同类型支座进行试验，试验结果表明该改进试验方法所得结果符合标准规定误差范围，为试验人员节省了大量时间，并且还消除了传统方法中的累计误差。

It was shown that the asymmetry in the elastic modulus results from the compressive residual stress in the fiber root and the asymmetry in the yield strength results from the tensile residual stress in the matrix and compressive residual stress in the fiber.

分析表明，纤维根区域的压缩残留应力造成弹性模量的不对称性，基体拉伸残留应力和纤维的压缩残留应力造成屈服强度的不对称性。

In the long time creep tests, by regressive analyses, the creep curve of glauberite at different stress level is obtained: at 50% of its compressive strength, the creep curve is ε 0.009t0.3265, at 80% of compressive strength, the creep curve is ε=0.0098ln-0.0014. It is clear from the creep curves of the rock mass, that the creep rate at high stress level is higher than that at the lower stress level.

通过长时间的蠕变实验，回归出钙芒硝盐岩蠕变在不同应力水平下随时间变化的曲线，其抗压强度50%时的曲线方程为ε=0.0098ln-0.0014，抗压强度80%时的蠕变曲线方程为ε=0.012ln-0.0056，应力水平高时其蠕变速率高于低应力水平的蠕变速率。

The research contents mainly include: First, the influence of foundation constraint condition to the temperature stress is analyzed, the temperature stress formula of ultra-long concrete anchor plate is deduced, then the influence of length to structure crack can be gotten from the formula. Second, a breathing method is set up to solve the problem of temperature stress in ultra-long concrete constructions. By setting the sliding floor, a breathing system is built up and the temperature stress reduced distinctly. Third, the effect of prestress technique in the control of temperature stress is analyzed, it is simulated and calculated through FEA to get the right way to apply the prestress. Forth, the delay of temperature field and unsteady conduction is considered, the temperature field of ultra-long concrete structure with later poured band is simulated, then temperature stress distribution after casting the concrete is calculated, finally the effect of later poured band to temperature stress of ultra-long structure is analyzed.

本文的研究内容主要包括：(1)分析了基础约束对超长混凝土结构温度应力的影响，推导了超长混凝土地基板温度应力公式，从而得出长度对结构裂缝的影响；(2)针对超长混凝土裂缝问题，提出了一种可呼吸的解决方法，通过设置滑动层，使结构成为一种"可呼吸"体系，从而有效的降低温度应力；(3)分析了预应力技术在控制超长结构温度应力中的作用，通过有限元模拟计算，得到合理的预应力施加方式；(4)考虑温度场的滞后效应及不稳定传导，对带后浇带超长混凝土结构浇注后的温度场仿真模拟，计算浇注后的温度应力分布，分析后浇带对超长结构温度应力的影响。

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。

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。

Results: 1. The value of all experimental indexes decreased significantly after heat stress, and reached the lowest at the time 2-8 hours after heat stress. This indicates that the immunity of the mice is damaged to the largest extent at 2-8 hours after heat stress. 2. L-arginine supplementation with appropriate dose could remit the acute atrophying of thymus and spleen tissue caused by heat stress. 3. After L-arginine supplementation with appropriate dose, the lymphocyte proliferation, the level of concentration of IL-2 and * expression of IL-2R raised in the group with room temperature; in the heat stress group the level of three indexs decrease significantly. Furthermore, the decrease of the group given 1 .Smglg.bw L-arginine is the smallest. This result indicates that the concentration of 1 .Smglg.bw L-arginine supplementation could remit the depressment of the immunity caused by heat stress. 4. The [Ca2~] in activated thymocytes of the group with L-arginine -2- supplementation is significantly higher than that of the group with water supplementation. This indicates that L-arginine supplementation could protect thymoeytes of mouse under heat stress. We also found that the fluorescence intensity of [Ca2~] in activated thymocytes of the group given 1 .Smglg.bw L-arginine is the highest.

结果：1、热应激后小鼠的各项免疫指标均有显著性下降，其中在2.8小时降到最低，提示在这个时间段小鼠的免疫功能受到最大损害；2、适量补充精氨酸有助于缓解热应激导致小鼠胸腺和脾脏的急性萎缩；3、常温组，补充适量精氨酸后小鼠淋巴细胞增殖活性、IL-2的浓度及IL-2R的表达均有显著性上升，而热应激后三指标均显著降低，其中在精氨酸给予浓度为1.5mg/g.bw时三指标的降低程度最少，提示该浓度可最大程度缓解热应激对小鼠免疫功能的抑制；4、补充精氨酸组的活化胸腺细胞［Ca~(2+)］较给水组有显著性上升，说明精氨酸对热应激小鼠胸腺细胞具有保护作用，并发现在精氨酸给予浓度为1.5mg/g.bw时活化胸腺细胞的胞浆钙离子荧光强度达到最大；5、热应激后小鼠血清NO的浓度均有不同程度的上升，补充精氨酸后血清NO上升更加明显，但并非随精氨酸给予浓度的增加而增加。

"Yes, now you can give yourself airs," she said, you have got what you wanted.

"对了，您现在高兴了，"她说道，这是您所期待的。

Then the LORD said to me: Rebel Israel is inwardly more just than traitorous Judah.

上主于是对我说：＂失节的以色列比失信的犹大，更显得正义。