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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。

To the crack in the rail surface, the effect of longitudinal location on the distribution of the elastic-plastic stress and strain in the railhead is calculated. The maximum stress around the crack in the rail surface over the yield stress and the steel around the crack has plastic strain.

对于条纹状钢轨表面缺陷，主要计算了不同横截面位置条纹状钢轨表面缺陷对轨头内弹塑性应力场和应变场的影响，条纹状钢轨表面缺陷的存在使其周围最大等效应力超过了钢轨材料屈服极限，导致该位置钢轨发生了塑性应变。

The shearing stress on an octahedral plane is used as a rarameter to analyse crack -producing problems under mixed mode fracture and the crack producing direction is considered as the direction with mimimal displacement from crack tip to plasticity boundary.

本文采用剪应力强度因子作为断裂的参数，分析复合型断裂问题，认为裂纹扩展方向为塑性区最短距离方向。

These work are mainly based on two assumptions: one is called as the Deeg-Pak assumption, i.e., the crack is assumed to be an impermeable slit and thus the electric field inside the crack is equal to be zero; the other is called as the Parton assumption, i.e., a crack is treated as a permeable cut across that both the normal components of electric displacement and the tangential component of electric field are continuous.

裂纹问题：对于压电介质内的裂纹问题，近十年来人们已做了大量的理论分析工作，这些工作主要是基于两种假设：一种称之为 Deeg-Pak 假设，即假设裂纹为电非渗透的，因此裂纹内的电场等于零；另一种称之为 Parton 假设，即假设裂纹为电渗透的，且跨越裂纹上下表面电位移的法向分量和电场的切向分量是连续的。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。