失效

It is clarified for the first time that the thermal fatigue failure of solder joint is actually a creep strain low cycle fatigue failure, and a physical model for creep fatigue crack propagation has been proposed. It was pointed out that creep strain increases in the high stress area ahead of the tip of thermal fatigue crack, results on one hand that the slide of crack tip increase, inactivation more serious and crack close length increases, the other hand, that intergranular crack exists, whose direction will affect the fatigue crack propagating.

本文首次阐明了焊点的热循环失效本质上是以焊点内循环蠕变为主要应变的低周疲劳失效，并在此基础上提出了蠕变疲劳裂纹扩展的物理模型，指出热循环裂纹前端的高应力区内，蠕变加剧，使裂纹前端滑移增加，裂纹钝化加剧，导致随后的裂纹闭合扩展长度增加；同时蠕变也使裂纹前端的高应力区出现晶间裂纹，蠕变沿晶裂纹对主裂纹扩展的影响取决于沿晶裂纹的连接方向。

Based on the practice of the use of φ95mm subsurface sucker rod pump in Shengtuo Oilfield in recent years, the causes of the failure of the pump are analyzed, and relevant precautions are put forward:(1)selecting oil wells with sufficient fluid supply for pumping;(2)under the condition of the pump efficiency being the same, the submergence depth of the pump being somewhat larger than that of the small pump, and 450～500m being feasible;(3)adopting Grade H ultrahigh-strength rod string and fixing a sinker bar at the bottom of the rod string;(4)selecting long stroke and low pumping speed, and more than 5m stroke and less than 6min-1 pumping speed being recommended;(5)adopting zirconium oxide valve ball and seat ＋ spray welded plunger ＋ nitrided barrel.

根据胜坨油田近几年采用φ95mm有杆抽油泵提液的实践，分析了造成这种抽油泵失效的原因，包括与其配套的脱节器失效、抽油杆断脱、泵漏、电动机不配套和生产管理不善等。为增强泵的提液能力和工作可靠性，提出5 项预防措施：(1)选择有充足供液能力的油井；(2)在保持相同泵效的情况下，泵的沉没度应略大于小泵，推荐按450～500m设计；(3)采用H级超高强度抽油杆柱，并在杆柱底部配置一定重量的加重杆；(4)采用长冲程、低冲次的参数匹配，推荐光杆冲程大于5m，冲次小于6min-1；(5)为提高泵筒、活塞和阀座的防腐耐磨性，推荐采用&氧化锆阀球和阀座+喷焊柱塞+氮化泵筒&的结构形式。

Two sets of measurements [38, 39] have been reported for the fracture of ropes of single-walled CNTs.

观察到的失效应变为2 13 ％，杨氏模量为0.27至0.95 TPa，失效应力介于11至63 GPa，平均值为28 GPa。

From all the work a set of complete methods of analyzing and calculating fatigue reliability of structure systems are put forward. The fatigue reliability of structure systems can be calculated by searching failure modes and using the series-wound model composed of the failure modes.

由此针对结构系统疲劳破坏的特点，本文提出了一套完整的结构系统疲劳可靠性的分析和计算方法，该方法通过搜索结构系统的主要失效模式，应用失效模式组成的串联模型计算结构系统的疲劳可靠性。

It is shown that the contact interaction enables bottom drillstring to whirl backward, and then an alternate bending stress with higher frequency is produced. So the drillstring fatigue failure could be accelerated. At the same time, a quite strong wallop force of high frequency is produced on the contacting point, and the contacting zone is next to the screw coupling of drill collars. It will easily result in the failure of screw couplings. The research results provide theoretical basis for the prevention of drillstring failure.

研究表明，下部钻柱与井壁的碰摩作用使下部钻柱反向涡动，产生高频的交变弯曲应力，会加速下部钻柱疲劳破坏；下部钻柱与井壁接触点处存在较大的高频冲击力，并且接触区域靠近钻铤螺纹联结处，更容易诱发螺纹联结处失效，该研究成果可为预防钻柱失效提供理论依据。

In the paper the author relates systematically the research fruits in the program of Research on Sand Slurry Abrasion Mechanisms of Dredging Conditions and New Wear-Resistant Materials. The main contents and innovations are listed as follows.Summarized and analyzed are the wear researches and developments, and the methods of increasing materials wear-resistance. From the viewpoint of the characteristics of two-phase liquid sand slurry wear, combined with the examination and study on easily damaged workpieces, the wear failures basic rules are pointed out, of the pump shell and the cutter-piece on service, and the general principles of material wear-resistant designs put forward. The sand slurry abrasion tester has been designed and developed which can simulate general dredging conditions. Summarized and presented are the position-exchange measuring method of sand slurry abrasion test and the experiment specification of sand slurry wear test of dredging conditions.

文中系统论述了作者在疏浚工况泥沙磨损机理及其耐磨新材料课题研究中的工作成果，主要研究内容和创新点如下：总结分析了磨损研究动态和提高材料耐磨性的方法；从两相流泥沙磨损的特点出发，结合对失效易损件的考察研究，分析指出了现役泥泵壳和绞刀片磨损失效的基本规律，提出了材料耐磨损设计的基本思想；设计研制了能模拟疏浚工况的泥沙磨损试验机，总结提出了泥沙磨损试验换位测试法和疏浚工况泥沙磨损试验规范。

Safety evaluation of high arch dam is related to the failure mode. It is necessary to find the most possible failure mode for the specified arch dam according to risk analysis. Then the safety degree of the dam relevant to the mode will be analyzed.

高拱坝安全度的评估需要与失效破坏模式联系起来，应通过风险分析寻找最可能失效模式，确定与此模式相应的安全度。

A brief account is given of the problem in traditional high arch dam safety evaluation without considering the randomness and without failure mode analyzing.

简述了高拱坝传统安全评价中不考虑随机性、不进行失效模式分析等存在问题，提出应用失效概率与风险值两个指标对高拱坝进行安全评价。

To counter the case which worm gear lost efficacy of rotating screen barrel rice mill ,reliability design theory was applied to analyze it.

针对旋筛式碾米机蜗杆传动时有失效的情况，运用模糊可靠性设计理论对蜗轮的强度进行分析研究，找出了蜗轮接触疲劳强度可靠度不足而失效的原因，将蜗轮材料由铸铁改为铝铁青铜，提高了蜗轮—蜗杆接触强度可靠度和弯曲强度可靠度。

The progressive collapse analysis on moment resisting frames of various span length, height and braced frames is analyzed. The curves of dynamic effect to column failure time and the displacement-time of column failure point are obtained.

采用动力非线性计算方法分别对不同跨度和高度的空间纯框架及框架支撑结构进行连续倒塌模拟分析，得到结构动力效应与柱失效时间的关系曲线和各失效点的位移时程曲线。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。