查询词典 principal stress

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。。。

Under soil water stress conditions, the photosynthesis rate, water useefficiency and light compensation point of Atriplex canescens obviouslyreduced, and its dark respiration rate weakened. In the treatments in July, theaccumulative and average value of daily Pn from high to low is: light soil water stress＞no soil water stress＞medium soil water stress＞heavy soil water stress, the valueare 7.162μmolm~(-2)s~(-1)、6.106μmolm~(-2)s~(-1)、6.103μmolm~(-2)s~(-1) and 1.761μmolm~(-2)s~(-1), respectively. In the treatments in August, the accumulative and average value ofdaily Pn from high to low is: light soil water stress＞medium soil water stress＞heavy soil water stress＞no soil water stress, the value are 7.378μmolm~(-2)s~(-1)、4.738μmolm~(-2)s~(-1)、1.794μmolm~(-2)s~(-1) and 1.705μmolm~(-2)s~(-1), respectively.

在土壤水分胁迫下四翅滨藜的净光合速率、水分利用效率、和光补偿点显著降低，暗呼吸速率减弱。7月份各处理Pn全天的累计值和平均值的大小顺序为：轻度土壤水分胁迫＞无土壤水分胁迫＞中度土壤水分胁迫＞重度土壤水分胁迫，它们的值分别为：7.162μmolm~(-2)s~(-1)、6.106μmolm~(-2)s~(-1)、6.103μmolm~(-2)s~(-1)和1.761μmolm~(-2)s~(-1)。8月份各处理的Pn全天累计值和平均值的大小顺序为：轻度土壤水分胁迫＞中度土壤水分胁迫＞重度土壤水分胁迫＞无土壤水分胁迫，它们的值分别为：7.378μmolm~(-2)s~(-1)、4.738μmolm~(-2)s~(-1)、1.794μmolm~(-2)s~(-1)和1.705μmolm~(-2)s~(-1)。9月份四翅滨藜的Pn变化趋势于8月份的变化曲线基本相似，唯一不同的变化就是各个处理的Pn比8月份的要高，这可能于9月份气温降低，湿度增大有关。

Experimental study of stress-strain relationship of normally consolidated intact soft clay in Hangzhou under undrained fixed shear of principal stress direction and monotonic rotation of principal stress axis had been done, which was used to reflect the soil properties response to the monotonic rotation of principal stress axis under real engineering conditions.

为反映真实工程条件下主应力轴旋转应力路径引起土体性状的变化，对杭州地区正常固结原状软黏土在固结不排水的主应力轴定向剪切和主应力轴单调旋转条件下的应力-应变关系进行试验研究。

Based on the former study of soils constitutive relation involving principal stress axes rotation,the influences of principal stress axes rotation on the distribution of stress and deformation of soils are provided through numerical simulation of plane strain problems of soils involving rotation of principal stress axes.

在含主应力轴旋转的土体本构关系研究的基础上，通过含主应力轴旋转的土体平面应变问题的弹塑性数值模拟结果分析，总结主应力轴旋转对土体应力分布与变形影响的规律，得出需要考虑主应力轴旋转的条件及其影响的相对大小。

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。

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。

Firstly, we collected and sorted out the GPS data, established the uniform velocity field for the Chinese mainland and the surrounding regions, and the horizontal deformation field relative to the Eurasia plate; Secondly, we established a motion model for the entire rotation and homogeneous strain of the first and second level blocks in Chinese mainland, analyzed the motion pattern and strain behavior of active blocks in Chinese mainland, as well as the motion pattern of principal fault zones in Chinese mainland; Thirdly, considering the heterogeneity of strain distribution inside a block and supposing that the strain tensor inside the block is the linear function of location, we derived and established an equation for the entire rotation and linear strain of block and a motion model for the entire rotation and linear strain of principal blocks in Chinese mainland; We also calculated the principal strain field and the maximum shear strain field in Chinese mainland and the surrounding regions, analyzed the basic characteristics of strain field in Chinese mainland, as well as the relationship between the spatial distribution of strain field and large tectonic zones; Finally, we established the 2-D geotectonic model and digital model for Chinese mainland and the surrounding regions, calculated the stress field in Chinese mainland and the surrounding regions, and analyzed the basic features of stress field in Chinese mainland and the principal driving force for the motion and deformation in Chinese mainland.

收集整理了已有GPS资料，建立了中国大陆及周边地区统一的速度场以及相对欧亚板块的水平形变场；建立了中国大陆一、二级地块整体旋转与均匀应变的运动模型；分析了中国大陆活动地块的运动状态，应变状态，以及中国大陆主要断裂带的运动状态；考虑到一个块体内部应变张量空间分布的非均匀性，假设块体内部的应变张量是位置的线性函数，推导建立了块体整体旋转与线性应变方程，建立了中国大陆主要地块整体旋转与线性应变的运动模型；计算了中国大陆及周边地区的主应变场与最大剪应变场，分析了中国大陆应变场的基本特征，以及应变场的空间分布与大型构造带的关系；建立了中国大陆及周边地区二维的地质构造模型和数值模型，计算了中国大陆及周边地区的应力场，分析了中国大陆应力场的基本特征以及中国大陆运动、形变的主要驱动力。

This article that focuses on the systematic and in-depth research in the current primal problem about abnormal burst pressure reservoir depress burst pressure has procured following main fruits:1 It forms the method which could obtain massive vertical static state mechanics parameters.2 In a foundation of acquisition of rock mechanics parameters,apply bent lamella that as mechanical model along with characteristic of actual geologic characteristics to analysis curvature for anticlinal strcture, get homologous tectonic stress value throug relation between the curvature and stress and different principal curvature in anticlinal structure,consequently set up laminational stress model for anticline reservoir. The block lamination for existed fracturing date has formed method of setting up mechanical model of lamination terrestrial stress by abtaining the block tectonic stress coefficients which are got by complex utilization test, laboratory test and fracturing date playback.3 Analysesing the main reason which lead to high burst pressure by considering the characteristic of reservoir geology,reservoir,and rock mechanics and reservoir damage,etc.Establishing burst pressure quantitative prediction model which provide gist for depressing construction risk and optimizing construction craft under the condition of open hole completion ,gun-perforated completion and damaged reservoir.4 Provding theoretical basis for interpreting acidification pretreatment which could depress busrt pressure by finding the relation between the influencing factors and rock machanics parameters and analysing the factors that have effect on rock mechanics parameters. Expounding the mechanism of reaction of mixed monomineral and acid from the angle of microcosmic element, evaluating quantitatively acid sensilility of different kinds of mineral effectively, and determing the first-order reaction dynamical equation of each mineral.5 Revealing rock mechanics property chage as a result of acid flooding in different condition by sandstone traumata experiment in different temperatures which combined with rock mechanics triaxial stress experiment.6 Associating damage mechanics with sandstone acidizing, established sandstone damage mechanics model in the foundation of the recognition on the rock mechanics parametric variation which is caused by acid-rock reaction in both macroscopic view and microscopic view ,also demonstrated those processes and quantitative estimated the acid busrt pressure to direct the site operation.

本文针对目前异常破裂压力储层降低破裂压力的主要问题展开较为系统和深入的研究，取得了以下主要成果：1形成了利用测井资料，结合室内岩芯测试结果，获取静动岩石力学参数的相关性特征，从而获得纵向上大量静态力学参数的方法。2在获取了岩石力学参数的此基础上，利用弯曲薄板作为力学模型，结合区块实际地质特征对背斜构造进行曲率分析，通过曲率与应力的关系，利用背斜构造不同部位的主曲率求得相应的构造应力值，从而建立起背斜储层的分层应力模型；对已有压裂资料的区块分层，形成了综合利用测试、室内实验、压裂资料反演获得该区块构造应力系数，建立起分层地应力的力学模型的方法。3综合考虑储层地质、油藏、岩石力学特性和储层伤害等因素，分析造成高破裂压力的主要原因，综合利用岩石力学、弹性力学等知识，建立了裸眼完井、射孔完井条件下以及储层受到伤害后的储层破裂压力定量预测模型，为降低施工风险和优化施工工艺提供了依据。4完成了物性、岩性影响岩石力学参数的因素分析，找出了各影响因素和岩石力学参数之间的关系，为从机理上解释酸化预处理降低破裂压力提供了理论基础；从微观元素的角度阐述了单矿物与酸反应的机理；并在此基础上，有效评价了各种矿物的酸敏感性，定量确定了岩石中各矿物的一级反应动力学方程。5完成了不同温度下的酸液类型、酸液浓度、注酸量等一系列砂岩损伤实验，结合岩石力学三轴应力实验，系统揭示了在不同条件下注酸而引起的岩石力学性质变化。6将损伤力学与砂岩酸化相结合，在宏观、微观两个方面认识酸岩反应引起岩石力学参数变化基础上，建立了砂岩损伤力学模型，并对其进行验证，在此基础上定量计算酸化后的破裂压力，有效指导现场施工

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。

"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。