破坏应力

The distribution of temperature stress was calculated by finite element analysis. The results showed when the surface temperature of concrete was higher than 110℃, the temperature stress was more than 4 MPa without regard to the creep. This might be lead to the damage of the surface of concrete. At the same time, a lot of microstructure analysiss such as XRD, SEM, IR, HSA etc. were done to analysis the difference of the component and microstructre of concrete before and after corrosion. The results indicated that the decomposion of CSH gel and calcium hydroxide and the creation of dilatability calcium oxide were the internal reason of the deterioration of concrete in the corrosion form of high heat.

该文通过有限元方法计算了由于温度而产生的结构应力分布，计算结果表明当混凝土表面温度超过110℃时，如不考虑徐变时表层混凝土受到的温度应力将超过4MPa，这使得表层混凝土很容易因温度应力而破坏；同时通过X射线衍射分析、扫描电子显微分析和混凝土孔结构分析等多种微观结构测试手段，分析了混凝土受热前后的宏观性能以及微观组成和结构的变化，指出混凝土原水化产物如水化硅酸钙凝胶和氢氧化钙的分解以及膨胀性产物氧化钙的产生是高热腐蚀形式下混凝土破坏的内在原因。

On the basis of the achieved result and the effect of stress such as minor principal stress, intermediate principal stress, hydrostatic pressure, stress Lode degree, a generalized hyperbolic failure function adapted naturally with the envelope form of Mohr-Coulomb criterion is proposed for brittle rocks; and a smooth failure function acquired by Yu Maohong is also presented. Thus, a generalized polyaxial strain energy strength criterion is created.

在分析脆性岩石强度的静水压力、中间主应力、最小主应力以及应力Lode角等4种效应的基础上，提出子午面上与Mohr-Coulomb准则包络线自然衔接的广义双曲线型破坏函数及八面体偏平面上光滑角隅型破坏函数，从而建立非线性广义多轴应变能强度准则。

It is embodied concretely:(1) With the adoption of grouting bolts, the cranny in wall rocks can be blocked up, the air can be isolated, the wall rocks can be prevented to be weatherized and make water, the strength of wall rocks can also be avoided to be lowered;(2) The lax broken wall rocks are commentated to a whole by liquid after they were grouted and the rock"s strength is increased, so the wall rocks become a part of the support structure by using itself and become a whole with the original rock, and the roadway is made to keep stable but not easy to be broken;(3) The spray layer wall are filled with liquid after grouting, the stress is avoided to be concentrated because the load could be evenly acted on the spray layer and the support;(4) The pressure acted on the plank can be delivered to the two sidepieces and then to the bottom by reinforcing the sidepiece; At the same time, the concentration degree of loads acted on the motherboard can be weaken because of the enlargement of the combination arch"s thickness, as result, the rock"s stress is lowered and the heaving is alleviated;(5) The common bolt is made to be fixed the whole length after grouting, the layers are connected to a integral whole and bear the weight of loads, so the support structure"s unity is increased.

具体体现在：(1)采用注浆锚杆注浆，可以利用浆液封堵围岩裂隙，隔绝空气，防止围岩风化，且能防止淋水和渗水，避免围岩被水浸湿而降低围岩的本身强度及造成的巷道变形。(2)注浆后浆液将松散破碎的围岩胶结成整体，提高了岩体强度，实现利用围岩本身作为支护结构的一部分，且与原岩形成一个整体，使巷道保持稳定而不易产生破坏；(3)注浆后使得喷层壁后充填密实，保证荷载能均匀地作用在喷层和支护上，避免出现应力集中点而首先破坏；(4)注浆后使作用在顶板上的压力能有效地传递到两帮，通过对帮的加固，又能把荷载传递到底板；同时由于组合拱厚度的加大，这样又能减小作用在底板上的荷载集中度，从而减小底板岩石中的应力，减轻底臌；(5)注浆加固后能使普通端锚锚杆实现全长锚固，它们共同将多层组合拱连成一体，共同承载，提高了支护结构的整体性。

The minimum principal stress criteria adopted in the new model ,compared with the minimum tangential stress criteria of traditional method ,illustrates the mechanism during hydraulic fracturing procedure more objectively.

新的理论模型采用了最小主应力破坏准则，与现有方法采用的最小切向应力破坏准则相比，更客观的表述了水压致裂过程中的力学机制。

While under the same anchorage conditions, the ultimate tensile stress in adhesive reinforcement of beam is much smaller than the ultimate stress in pull-out test of block specimen.

将植筋搭接梁的试验结果与块体试件植筋锚固单向拉拔试验的结果比较表明，在相同植筋条件下，梁式试件破坏时钢筋的应力远小于块体试件单向拉拔试件破坏时钢筋的应力。

By way of parenthesis, In One-Point Input Method the relation is studied between the response and the correlative coefficient of horizontal and vertical earthquake wave.

提出了基于动剪应力极值的土体损伤值计算方法。以往计算土体在不规则的动剪应力作用下的损伤值根据的是动剪应力的峰值，在时域内多点输入分析中，由于差动力的的存在，使得时程后段动剪应力不穿零而在一侧做幅度不大的波动，基于峰值的损伤值计算特别过高地估计了这段剪应力的破坏作用，过高的程度还随延时增加而增加。

The results show that the mechanical properties of this PMMA depend strongly on the testing temperature. The Young's modulus and flow stress were found to decrease with increasing temperature at low strain rate. At the strain rate of 10^(-1) 1/s, strain soften was observed under all experiment temperatures. At high strain rate, with the temperature increase, the flow stress deceases remarkably while the failure strain increases, and the strain softening was also observed at the temperature above 333K.

试验结果表明：在准静态载荷下，随着温度的升高，材料的弹性模量和流动应力减小，在应变率为10^(-1) 1/s时表现出明显的应变软化行为；在高应变率(550 1/s)下，随着温度的升高，材料的流动应力逐渐减小而破坏应变增大，当温度超过333K时也有应变软化现象发生；在相同温度下，随着应变率的升高，材料的流动应力增大，但破坏应变减小。

Based on present researches,by means of modern measurement and analysis techniques,systemic laboratory experiments,field investigations and through theory researches were conducted.And following are the major points and achievements presented in this dissertation:①The micro-convexity on fracture plane was studied.Analyzing and comparing the static attribute and dynamic variation of natural fracture with the artificial,untreated fracture,artificial and scabbled fracture as well,making out the criteria that artificial and scabbled fracture simulate natural fracture.②We take the effect of all the three primary stresses and stress invariant into account in the Lade-dbl yield criterion,which can preferably reflect all the yield and destruction characteristic of the rock material.

结合裂缝性储层应力敏感性研究现状，利用现代化测试手段，通过系列的室内实验以及深入的理论探讨，本文取得的研究成果包括以下几个方面：①从裂缝面上的微凸体入手，分析和对比了天然裂缝、人工但未经过处理的裂缝，以及经过粗化处理以后的人工裂缝的静态特征和动态变化，指出了经过粗化处理以后的人工裂缝模拟天然裂缝的依据；②Lade双曲服面屈服准则考虑了所有三个主应力或应力不变量对屈服与破坏的影响，能够较好的反应岩石材料的所有屈服和破坏特性。

In the process of impact of abrasive jet on rock, resulting dynamic stress plays an important role in rock destruction. The stress wave resulted makes local rock tensile and shearing, then makes rock destructed. In the conditions of some hypotheses, the mechanical model that rock is applied by stress wave, i.e. jet wave basic equations, are set up by wave theory, and the formula of the maximum normal stress resulted by stress wave is deduced according to known boundary conditions.

描述了岩石材料在磨料射流的冲击下破坏的主要原因，分析了应力波就是岩石局部受到拉伸和剪切并最终使岩石发生破坏的根本因素，在这一假设的前提下采用波动理论建立了岩石受应力波作用的力学模型即射流波动的基本方程，在已知的边界条件下推导出了由波动引起的最大正应力的计算公式。

The foundation soil is divided for finding the ultimate bearing capacity of a foundation with given buried depth and size. Supposing a uniform load acts on the foundation, Mindlin's integral formula and comer points method are used to get extra stress of every mesh knot by MATLAB program, then the principal stress is found. Combining with failure criterion, MATLAB program is used to find coordinates of points which are destroyed. Using graphic processing function of MATLAB, the failure points are showed in the coordinate.

为确定作用在已知埋深、给定基础形状地基土上的极限承载力，对基底下的土体进行网格划分，先假定一均布荷载作用在此地基土上，运用明德林解的积分公式，结合角点法，编制MATLAB语言程序，求出每个网格节点上附加应力，进而求得每个网格节点上主应力，根据破坏准则，结合程序找出破坏点的坐标，利用MATLAB的图形处理功能，把破坏点的坐标在坐标图中显示出来。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。