破坏应力

Inner of high temperature is very easy to dock a place to the steel tube coating creation destroys welding because the operation is complicated and Asbestus rope heat insulation effect. Change in the area metallographic organization fever of arousing is affected and the remaining strain arouse strain corroding a dehiscence to create inner steel tube bringing about the ring oxygen powder series falls short of success. Carrying out a certificate is not a preferred plan.

此种方法由于扩口时的精度不高，现场施工环境和条件所限，很难达到预期的效果，加之操作复杂、石棉绳绝热作用的不充分性等引起的焊接高温很容易对钢管对接处的内涂层产生破坏，同时还引起热影响区金相组织发生变化、产生残余应力而引起应力腐蚀开裂，造成环氧粉末系列的内防腐钢管功亏一篑，实践证明不是最佳方案。

Firstly,according to the mechanical properties of soft clays and the traffic load induced dynamic deviator stress ,the static failure deviator stress was determined.

首先通过确定车辆荷载引起的动偏应力和土层的力学指标计算出静力破坏偏应力，然后通过考虑土物理力学性质、循环荷载次数的累积变形公式计算软土地基中各土层在车辆荷载作用下引起的残余累积应变，最后用分层总和法计算总沉降。

Theobserved strain is 10~2 times as local point strain at the same observed stress.This indicates that macroscopical symmetrical rock is quasi-brittle materialwith microcosmic heterogeneousness and its macroscopical mechanicalbehavior is the results of reciprocity and magnification between microcosmiccharacteristic, not simple sum.(4) The degree of irregularity of strain increases with the number of cycle.But degree of irregularity of transverse strain fluctuates larger at the samecycle. Moreover degree of irregularity of transverse strain is larger than that ofaxial strain. This shows that deformation and failure of rock is process ofevolvement of small crack. Small crack evolves from even and out-of-orderstatus to heterogeneous and ordinal status.(5) Ultrasonic speed decreases with the number of cycle. The decreasecourse is such: Firstly, ultrasonic speed fluctuates in a steady scope in somecycles; And then ultrasonic speed quickly decreases to a certain more smallvalue; Afterwards in succedent cycles, ultrasonic speed fluctuates about thevalue. That is to say, ultrasonic speed fluctuates and decreases at intervals ofcycles. In deformation process of rock, quantitative change and qualitativechange of its small crack evolvement carry through crosswise.(6) Strength and modulus of rock decrease with exponential function asscale of specimens increases.

同一表观应力下，局部点应变与表观应变相差可达2个数量级，表明宏观上均匀的岩石是具有细观特征的准脆性材料，其宏观力学行为是细观特征相互作用、放大的综合结果，而不是简单的叠加；(4)岩样轴向应变不均匀程度和横向应变不均匀程度随循环次数的增加渐进增大，但是在同一个循环内，横向应变离散系数随应力的变化波动较大，且同一循环级别下，横向应变不均匀程度大于轴向应变不均匀程度，表明岩石内部微裂纹的演化是岩石变形破坏的本质特征，这一演化表现为微裂纹从均匀无序分布逐渐向非均匀有序发展；(5)随循环次数的增加，所有岩样内部超声波速会出现衰减，衰减过程表现为在某几次循环内超声波速在某一相对范围内波动，然后急剧减小到某一较小值，在随后的循环内，超声波速又会保持在这一较小值附近波动，即超声波速表现为波动和急剧减小间隔形式衰减，表明从宏观看来平稳的岩石变形过程，内部结构演化过程(微裂纹发展及其相互作用)却表现为均匀量变和突发质变不断交叉进行的现象；(6)岩石强度和弹性模量随尺度增大呈指数函数规律减小。

The failure criterions of principal stress, octahedral stress and strain space are established.

建立了主应力、八面体应力和应变空间的混凝土破坏准则。

The results show that, with the expansion cone angle remaining unchanged, the sizing length of expansion cone does not have much effect on the residual stress of casing after expansion, but it has much effect on the expansion force required by tube expansion. The expansion cone angle has no effect on the maximum residual stress of casing, but it has remarkable effect on expansion force. When the radial component force of expansion force is greater than the material's tensile strength, the damage to the material will arise.

研究结果表明，在膨胀锥锥角保持不变的情况下，膨胀锥定径长对膨胀后套管的残余应力没有太大影响，但对套管膨胀所需要的膨胀力有较大影响；膨胀锥锥角对套管最大残余应力没有影响，但对膨胀力的影响十分明显，当膨胀力的径向分力大于材料的抗拉强度时，材料将发生破坏。

It is indicated that loosely compacted soil is of strain-softening behaviour under undrained conditions, accompanied with a rapid increase in excess pore water pressure. In anisotropically consolidated constant shear stress tests, a very small axial strain was required to induce the failure and the excess pore water pressure increased quickly at failure.

研究表明：松散填土在不排水条件下具有应变软化的特性，软化过程中伴随着孔隙水压力的迅速上升，有较高的液化势；在常剪应力排水剪条件下，具有破坏前轴向应变小、破坏时间短，破坏过程中孔隙水压力迅速上升。

Secondly, the paper carries on the destruction processes and the stress distribution situation numerical simulation of the concrete three point bending specimen with bias crack under static load function,, and analyze specimen crack expansion and the destruction mechanism, obtain the reason that the crack expanding flectional way is because the material nonuniformity, in the same time, from the specimen destruction process chart we can see that the crack bias degree has some influence on the crack expansion way.

其次论文对含偏置裂纹的混凝土三点弯曲试件在静态载荷作用下的破坏过程和应力分布情况进行了数值模拟，并对试件的裂纹扩展和破坏机理进行了分析，得出裂纹扩展的曲折性是由于材料不均匀性所引起的，同时从试件的破坏过程图中可以看出，裂纹的偏置程度对裂纹的扩展路径有一定的影响。

The criterion is similar to hyperbolic strength criterion including uniaxial compression strength and uniaxial tensile strength, which is an extended form of Griffith-Murrell criterion essentially under the condition of polyaxial stress when hydrostatic pressure is lower, and it represents the first failure type. However, the criterion is similar to generalized Mises criterion when hydrostatic pressure is higher, and it represents the second failure type. The transition part between the two criteria represents the third failure type when hydrostatic pressure is high.

该准则包含单轴抗压和抗拉强度，在静水压力较低时，实质上它是Griffith-Murrell准则在多轴应力状态下的一种扩展形式，反映脆性岩石破坏类型1；在很高静水压力下该准则可转化为广义Mises准则，反映脆性岩石破坏类型2；而当静水压力较高时，该准则处于上述两种准则的过渡阶段，反映脆性岩石破坏类型3。

It indicates that the damnification morphology of K9 glass is cleavage damage, the reason of which is that the hoop tensile stress overtops materials'tensile strength. And the materials'damage threshold is inversely proportional to irradiation time.The mathematical model of in-band CW laser irradiating optical material is established.

结果表明：K9玻璃材料的损伤形态为解理破坏，破坏的原因是环向拉伸应力大于材料的抗拉强度，且材料的损伤阈值与辐照时间反向相关，即激光功率密度越高，造成破坏所需的时间越短。

Because of complex tectonic boundary condition and high stress environment in deep rock mass,surrounding rock has intrinsic characteristics,which will damage caused by stress redistribution in excavation of deep-buried tunnel .

随着细观损伤岩体力学的发展，采用损伤观点解决深埋隧道围岩破坏问题逐渐显示出其优越性，但目前仅在均质性假设的基础上对应力状态和破坏判据进行研究，缺乏对其破坏全过程的相关研究。

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。