| 1. | The j - integral value is variational alone the thickness , and the value of unpatched side is much higher than that of patched side
裂纹板修补后的j积分值有明显降低；并且裂纹越长，修补效果越显著； 4 |
| 2. | Ctod ( crack tip opening displacement ) and j - integral are two important parameters in elastic - plastic fracture mechanics
Ctod ( cracktipopeningdisplacement )和j积分是弹塑性断裂力学研究方法中的两个重要参数。 |
| 3. | A new method for calculating the strain energy release rate of delamination crack propagation at an interface between dissimlar materials was suggested by using the j - integral with a small flat rectangular contour near the crack tip
提出了一种通过特定的扁平小矩形路径j积分，计算电子封装中异质界面分层裂缝扩展能量释放率的新方法。 |
| 4. | The strain energy release rates g near crack tip under different conditions were calculated by employing three methods of the fracture mechanics ( j - integral , straightforward method and crack tip opening displacement method )
并在有限元模拟中采用三种不同的断裂力学方法(裂缝顶端开口位移方法、直接方法、 j积分方法)计算了焊点断裂与否时的能量释放率g 。 |
| 5. | This paper elaborates ctod and j - integral completely beginning with the basic concept of the two parameters , moreover , it performs an easy review to the relationship between them along with the computational methods and experimental means respectively
本文从ctod和j积分的基本概念入手，对这两个参数进行了全面阐述，并且对它们之间的关系问题以及各自的计算方法和试验方法做了简单的回顾。 |
| 6. | J - integral has noting to do with the integral line , so it can evade the complex stress - strain field near the crack tip , moreover , j - integral is a stress - strain field parameter with clear definition and close theory , so it is very popular to the field of mechanics
J积分具有与积分线路无关这一特点，故可避开裂纹尖端处极其复杂的应力、应变场，并且j积分是一个定义明确、理论严密的应力、应变场参量，因而受到了断裂力学工作者的青睐。 |
| 7. | Because both of ctod and j - integral can be used to evaluate structure security , there must be a relationship between them , this paper probes the relationship between ctod and j - integral along with their critical value c and jic on the basis of the fruits from the original
由于ctod和j积分都可以作为结构安全评定的参数，它们之间必然存在着一定的联系，本文在前人研究成果的基础上，对ctod和j积分及其特征值_ c和j _ ( c )的关系进行了探索。 |
| 8. | An additional experiment is performed , and the weld specimens and heat effected zone specimens of dh36 steel are researched , through which the outcomes from the formulas of the standard and from other formulas is compared , which demonstrates the validity of standard test means for ctod and j - integral
另外还进行了一个附加试验，对具有不同尺寸的dh36钢的焊缝试样和热影响区试样进行了研究，将本文所用标准中公式的计算结果与其它经验公式的计算结果进行了对比，进一步证明了ctod和j积分标准试验方法的有效性。 |
| 9. | Because the calculation of j - integral is much simpler than other method , and the multilayers and interfaces are ubiquitous in microelectronic packaging structures , it is expected that this method will be widely used in the calculation of the strain energy release rate in high density electrical packaging , especially
并通过实例证明，此新方法对于界面分层问题是可行的。由于j积分计算十分简便，因此扁平小矩形路径j积分方法有望在电子封装分层能量释放率计算中得到广泛的应用。 |
| 10. | A finite element analysis ( fea ) was eventually conducted , using mori - tanaka model and j - integral , to further explain the toughening mechanisms and fracture behaviour of the particle interleaved composites . the aim of the analysis was to examine the influence of the particle concentration and size , and the interaction between the particle and the crack tip . fea results indicate that interlayer zones can effectively lower j - integral and stress around the crack tip , and the high stress distribution in the region close to the interface can be the driving force for interfacial failure
本文的最后还借助于有限元方法对层间增韧复合材料进行了宏观和细观断裂韧性分析，基于mori - tanaka等效夹杂理论，计算了颗粒含量和尺寸对j积分的影响，有限元分析的结果同样表明层间增韧可以有效的降低裂纹尖端应力水平，并暗示界面是可能存在的失效原因，所进行的数值分析起到了进一步支持和解释增韧机理的作用。 |
