查询词典 crack

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。

Plane strain, mode I quasi-static steady state crack growth is investigated utilizing the finite element method. It is once again established that TNT plasticity can significantly increase the stress level near the crack tip. The crack tip stress singularity is higher than or equal to the square-root singularity of elastic K field and is also independent of the plastic hardening exponent.

采用有限元方法研究了平面应变Ⅰ型准静态的稳态裂纹扩展，再次证实TNT非局部理论能够显著提高裂纹尖端附近的应力水平；裂尖应力场的奇异性超过或等于弹性K场平方根奇异性，而且与塑性硬化指数无关。

On the research of the propagation of the fatigue crack in the past 10 years, Paris and Zheng-hart have developed good formulas of the propagation of the fatigue crack of metal , but of which only describe the process of the propagation of the fatigue crack.

在近几十年对疲劳裂纹的扩展的研究中，Paris和Zheng-hirt对金属材料疲劳裂纹扩展的研究给出了很好的扩展表达式，但都是对疲劳裂纹扩展部分过程的描述。

Based on the fundamental principles of the improved method mentioned above, multi-functional computation software package, which can be used to analyze effectively the interference effects of random flaws in plane problem, boundary problem and space problem, is compiled and a number of problems involved in the interference effects of different kinds of flaws such as random equal length through-cracks, random branched throughcracks, random unequal length through-cracks, random holes to through-cracks, unequal length edge cracks, equal length and distance multiple edge cracks, random notches with different aspect ratio, random notch to edge crack, non-coplanar surface cracks with different aspect ratio, staggered surface cracks, surface crack to embedded crack and embedded cracks near free boundary are analyzed and computed by the package.

依据上述改进法的基本原理，本文编制了能有效地分析平面问题，边界问题及空间问题的任意缺陷群相互干涉效应的多功能计算软件包。据此，本文分析计算了各类缺陷群。诸如，任意等长裂纹群。任意折裂纹群；任意不等长裂纹群，任意孔与裂纹群，不等长边裂纹群。等长等间距多裂纹群，任意形状比缺口群，任意缺口与边裂纹，非共面不同形状比表面裂纹群，交错型表面裂纹群，表面裂纹与埋藏裂纹群及自由边界附近埋藏裂纹群等的相互干涉效应问题。

It includes hardware equipments and foundational theory of the image digitization. This paper expatiates on some digital image processing technologies that the inspecting system may apply to the research and analysis of the collected glass-crack image. Using neighborhood average method and median filter retrains the image noises and make the image edge smooth. Then protract the histogram of the gray image, get the threshold of this image, utilize the threshold method and gray-level slice method to get a binary image, and detect the image edge. Finally calculate the area and perimeter of the glass-crack image, and use the circularity to judge whether this image is a glass-crack image.

本文重点阐述了研究和开发这套玻璃瓶裂纹检测系统所应用到的一些数字图像处理技术，并应用这些技术和方法对采集的裂纹图像进行了处理和分析：应用邻域平均法和中值滤波法来抑制图像的噪声，使图像的边缘平滑；然后绘制出处理过图像的灰度直方图，得到该幅裂纹图像的阈值，利用阈值法和灰度级切片法对裂纹图像进行二值化处理，得到其二值图像，并对图像进行了边缘检测；最后计算出裂纹图像的面积和周长，利用圆形度指标来判断该图像是否为裂纹图像。

The crack spacing of CRCP changes randomly and has a significant impact on the pavement durability and performance. The direct integration method is used to analyze the reliability for crack spacing and width. The results show that the main factors that affected the reliability are the design crack spacing and the variability of parameters. This paper presents a nomogram for reliability calculation.

CRCP的裂缝间距是随机变化的，裂缝间距的不同会对路面耐久性产生显著影响，本文使用直接积分法计算了CRCP裂缝间距的可靠度，并使用蒙特卡罗法进行了对比，分析参数的敏感性，指出影响可靠性最主要的因素是设计裂缝间距及参数的变异性，给出了CRCP可靠度计算诺谟图。

Therefore, on the foundation of abroad research, this text describes the first and second order of crack turning theory, the influence of plasticity zone of crack tip and fracture resistance orthotropy of material to crack propagating trajectory.

因此，本文在国外文献的基础上，对裂纹转折的一阶和二阶理论以及材料裂纹尖端塑性区和断裂韧性各向异性对裂纹扩展路径的影响进行了描述。

The detailed algorithm on analyzing cracks exploration inside blocks is: enriched approximations which describe singular crack tips fields and discontinuous crack faces are employed under the Partition of Unity theory; the enriched nodes surrounding crack tips or faces are respectively mapped with corresponding enriched degrees of freedom, and the solution of all these degrees of freedom is uniformly proceeded by the implicit iteration algorithm of DDA, then fracture and breakage of DDA blocks can be analyzed. The numeric examples show this algorithm is rational and efficient.

为此建立的无网格法裂纹扩展分析算法，采用满足单位分解条件的特殊增强型函数表达裂纹周围应力场的非连续、奇异特性，将对应的扩展自由度动态映射到裂纹周围的节点上，统一按DDA法隐式迭代方式求解，实现块体裂纹扩展和强度分析，相关算例结果显示该算法是合理有效的。

Based on the fictitious crack model and critical crack tip opening displacement CTODc, the precritical crack propagation length △ac of concrete was determined by means of three point bending beams. According to the calculation value of △ac, the effective fracture toughness KunIc of concrete was evaluated.

本文采用虚拟裂缝模型，将临界裂缝尖端张开位移CTODc作为控制参数，利用三点弯曲梁试件通过迭代求得了混凝土裂缝亚临界扩展量的临界值△ac，据此求得了混凝土起裂断裂韧度KiniIc、等效断裂韧度KunIc值。

In the equation, the unknown parameters are determined by the crack initiation angle, the crack length and the angle between the direction of the maximum principal stress and the crack surface.

采用双曲线翼型裂纹路径和试验中所得翼型裂纹路径进行了对比分析，二者吻合得很好，验证了采用双曲线近似表示真实存在的翼型裂纹模型的正确性。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了