破坏应力

The X-ray photo, tectology, and the superfine structure of cells all display: The healing of the horizontal-shaped fracture is faster than that of the skewed fracture in the early and middle stages of fracture (2, 4, 6 weeks after operation).

而斜形骨折因骨折断端不在同一平面上，所受应力和位移相差较大，近端受力大，位移小，远端受力小，位移大，要使之破坏只要较小的加载力骨折近端即可首先出现断裂，继之因应力集中而波及整条骨折线，使骨骼再次骨折。

Based on the theories of rheology, Non-Newtonian Fluid Mechanics, petroleum chemistry, crystallography and pipeline technology etc. and sampling Huabei crudes, experimental indexes and programmes are drew out, integrating the oil properties and parameter analysis; in terms of the macro analysis of continuum mechanics, substantial experiments are conducted with HAAKE RS600 rotational rheometer and the rheological equation as well as the viscosity-temperature equation are further developed with tested rhrogramme and viscosity-temperature curve, respectively. Beased on the researches on thixotropic mechanism and thixotropy fluid property, hysteresis loop curve, structure failure and viscosity build-up curve as well as shear stress decrement curve for one type oil are first present in this paper. According to the theoretical researches and testing results, a novel thixotropy equation with τ=τ_∞e~ pattern, which is of hi-accuracy, few parameter and simplicity, is developed. Considering the influence of various parameters on rheological behaviour, depressant adding condition is optimized and experimental evaluation on BEM-5P is conducted, which further unrip its mechanism on the Huabei crude. A corresponding viable pipe transportion programmel is also recommended.

本文基于原油流变学、非牛顿流体力学、石油化学、结晶学、原油管输工艺学等理论，以华北原油为研究对象，结合原油物性及实验影响因素分析，制定出实验研究的评价指标及实验方案；从连续介质力学宏观分析的角度，利用HAAKE RS600高端旋转流变仪开展了大量的室内实验，并运用微观研究方法，测定了油样的流变曲线和粘温曲线，建立了流变方程和粘温方程；通过对触变性机理和触变性流体特征的研究，首次对华北原油测定出滞回环曲线、结构破坏与恢复粘时曲线、剪切应力裂降过程曲线，并在理论研究和实验结果的基础之上，建立了能定量描述含蜡原油剪切应力裂降过程的新型三参数触变模式τ=τ_∞e~b/(t+c，该模型具有精度高、参数少、实验简便且适用性强的特点；通过对含蜡原油流变性的影响因素理论研究，开展了加剂条件优选及BEM-5P降凝剂室内评价实验，进一步揭示了降凝剂对华北原油作用机理，在此基础之上，提出了华北原油管输的可行性方案。

Based on the theories of rheology, Non-Newtonian Fluid Mechanics, petroleum chemistry, crystallography and pipeline technology etc. and sampling Huabei crudes, experimental indexes and programmes are drew out, integrating the oil properties and parameter analysis; in terms of the macro analysis of continuum mechanics, substantial experiments are conducted with HAAKE RS600 rotational rheometer and the rheological equation as well as the viscosity-temperature equation are further developed with tested rhrogramme and viscosity-temperature curve, respectively. Beased on the researches on thixotropic mechanism and thixotropy fluid property, hysteresis loop curve, structure failure and viscosity build-up curve as well as shear stress decrement curve for one type oil are first present in this paper. According to the theoretical researches and testing results, a novel thixotropy equationwith τ=τ_∞e~ pattern, which is of hi-accuracy, few parameter and simplicity, is developed.Considering the influence of various parameters on rheological behaviour, depressant adding condition is optimized and experimental evaluation on BEM-5P is conducted, which further unrip its mechanism on the Huabei crude. A corresponding viable pipe transportion programmel is also recommended.

本文基于原油流变学、非牛顿流体力学、石油化学、结晶学、原油管输工艺学等理论，以华北原油为研究对象，结合原油物性及实验影响因素分析，制定出实验研究的评价指标及实验方案；从连续介质力学宏观分析的角度，利用HAAKE RS600高端旋转流变仪开展了大量的室内实验，并运用微观研究方法，测定了油样的流变曲线和粘温曲线，建立了流变方程和粘温方程；通过对触变性机理和触变性流体特征的研究，首次对华北原油测定出滞回环曲线、结构破坏与恢复粘时曲线、剪切应力裂降过程曲线，并在理论研究和实验结果的基础之上，建立了能定量描述含蜡原油剪切应力裂降过程的新型三参数触变模式τ=τ_∞e~b/(t+c，该模型具有精度高、参数少、实验简便且适用性强的特点；通过对含蜡原油流变性的影响因素理论研究，开展了加剂条件优选及BEM-5P降凝剂室内评价实验，进一步揭示了降凝剂对华北原油作用机理，在此基础之上，提出了华北原油管输的可行性方案。

And destruction usually occurs on angle.(2)Around the keyhole, the stress centralizes, column" edge opt to inflects in local.(3)The change of friction coefficients or bolt pretension forces can"t affect the performance of top-and-seat angel connections so much.(4)The parameters of angel influence joints performance greatly.

破坏一般是由于顶角钢上应力过大，形成塑性铰而导致的；(2)柱翼缘在与顶角钢相连的螺栓孔周围，存在应力集中，容易导致局部屈曲；(3)材料抗滑移系数的改变和螺栓预拉力的大小对于节点受力性能的影响并不明显；(4)角钢参数的改变对节点的各项性能影响显著，增加角钢厚度，节点的强度、刚度和延性都能得到明显的提高；增加角钢长度，节点的强度和刚度也有较大的提高，延性则略有下降；(5)柱轴压比过大时，节点的承载力、刚度以及变形能力明显下降；(6)螺栓中心线到角钢肢背距离增大时，节点的强度和刚度有所下降，但延性略有增加。

By adopting strain intenerated model and using numerical calculation of FLAC(Fast Lagrangian Analysis of Continue), deformation and destruction course under pick cutting is researched, different parameters' great influence on plasticity district, max displacement, max main stress and max shearing stress under the various kinds of operating modes is analyzed.

采用应变软化的模型，使用连续介质快速拉格朗日分析法(FLAC，FastLagrangianAnaly-sisofContinue)进行数值模拟计算；研究截齿截割作用下煤体变形破坏过程；分析各种工况下不同参数对煤体塑性区、最大位移、最大主应力、最大剪应力的影响。

After combining mathematical statistics method with the nonlinear hyper-elastic constitution model for SFRC, the complete stress-strain curve of SFRC may be prognosticated by using a part of the data of stress- strain.

通过将数理统计方法与SFRC非线性超弹性本构模型结合，只要知道了材料破坏的局部应力-应变信息，就可以预测SFRC的应力-应变全过程曲线。

Through above numerical analysis of the TiN coating/substrate system, some typical rules about the fatigue failure are found:(1) the fatigue damage of a coating/substrate system appears first on the interface, then expands along the interface and to the substrate, and finally causes the coatings broken and spalled;(2) under the cyclic loadings of tangential sliding and radial extrusion, the equivalent plastic damage on the interface is mainly generated by the shear stress and the accumulated plastic contributed by the increments of shear stress. Thus the change of the shear stress is the main factor for the contact fatigue damages of coating/substrate system;(3) the frictional coefficient, external loading and coating thickness have some influence on the carrying capacity and contact fatigue life for a coating/substrate system.

通过对TiN涂层／基体系统的数值模拟分析，得到了涂层／基体系统疲劳失效的一些典型规律：(1)、涂层基体的初始损伤首先出现在交界面处，然后沿界面并向基体中扩展，最后导致涂层断裂而发生剥落失效；(2)、在切向滑动和径向挤压循环载荷作用下，交界面处的塑性损伤主要是由剪应力τ产生，塑性累积也是由于△τ的变化引起，说明循环过程中剪应力变化是影响涂层接触疲劳破坏的主要因素；(3)、材料摩擦系数、外界载荷大小以及涂层厚度都对涂层／基体系统的承载能力以及疲劳寿命都有一定影响。

Based on the macroscopic response of quasi-brittle materials, the improved parallel bar system model which considers the equivalent relationship between effective stress and nominal stress of damage materials has been established.

修正平行杆模型是基于准脆性材料单轴受拉破坏的宏观表现，考虑损伤材料名义应力和有效应力之间的等价关系，建立的考虑均匀损伤的物理模型。

When the speed of piton changes from several positive meters per second to negative during short time , a huge transient impacting force acts on the piston. The force spreads in the piston with stress wave. Converging force will become at some sections, which can destroy the piston.

从风动冲击器的工作原理可以得知，风动冲击器的活塞在高压气流的推动下，反复冲击钻头，冲击时活塞的速度由向下的几米每秒在极短时间内反弹为向上的速度，因而对活塞产生一个极大的瞬时冲击力，该力以应力波的形式在活塞内传播，就会在活塞的某些断面产生应力集中，造成活塞的破坏。

Research also provides a finite element method for the study of masonry walls seismic behavior. Firstly, through the stone-dust mortar compressive experiment, pressure experiment, blocks bending experiment, water blocks experiment, 3 slabs shear experiment, diagonal loading experiment and the compression experiment, the values of compressive strength, bending strength, average water weight are obtained. Then the shear breakage of the masonry, behavior of shear stressτvaring withσ, load-displacement curves, ladder-shaped slit shear strength, shear strength of links linking, compressive strength and elastic modulus are also presented.

首先通过石头粉砂浆抗压试验、砖块压力试验、砖块抗折试验、三砖抗剪试验、对角加载试验、短柱的承压试验等测得了石头粉砂浆的抗压强度，砖块的抗压强度，砖块的抗弯强度，以及砌体剪切破坏形态、剪应力τ随正应力σ的变化规律、砌体对角压墙片的载荷-位移关系曲线、阶梯形缝抗剪强度及通缝抗剪强度和弹性模量。

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。