寿命

5A kind of stress-relief groove of box thread joint has been developped. Finite Element models of several thread joints have been established by ABAQUS. The Morrow Strain-life Model is used to evaluate the fatigue life of 3 kinds of connections with different stress-relieaf grooves of box. The results show that the fatigue life of box with stress-relief groove developed in the paper is the longest.

为了定量评价几种螺纹接头的疲劳寿命大小，采用Morrow应变周期模型结合有限元分析结果计算3种具有内螺纹应力减轻槽母扣的疲劳寿命，计算结果表明本文设计的内螺纹应力减轻槽能显著延长母扣的疲劳寿命。

Basing on the statistic datum existed of bridge deck pavements, analyze the main failure modes and its main causes to damage on different styles of bridge, at the same time, through the big calculation software ,establish the space models to simulate the course of mechanics of bridge deck pavements, analyze the main factors which affect the bridge deck pavement"s mechanics and the relations between them; according to the atmospheric circulation circumstances of bridge deck pavements, take the statistic datum of using life of prefabricated T-beam、box girders and casting girder in region of HUA-NAN as examples to returning analysis ,establishing the life prediction model of this style bridges; associating "the Method of Estimating to Life Cycle Costing,bring forward this method to take a evaluation of economy on bridge deck pavements, insure the life cycle costing reasonable; giving some tactics on the design of bridge deck pavements.

以既有桥梁的桥面铺装层使用现状统计资料为基础，分析了各种类型桥面铺装层的主要破坏形式及其主要损伤原因，同时利用结构分析软件，对桥面铺装层建立空间模型模拟其受力作用过程，分析影响桥面铺装层受力大小的主要因素以及各因素与铺装层受力大小之间的关系；按照桥面铺装层所处环境的不同，以华南地区预制T、箱梁和现浇梁的桥面铺装层正常使用寿命统计数据为例，通过回归分析建立该类型桥面铺装层的正常使用寿命预测模型；利用寿命周期费用评价方法，对特定铺装层的设计方案某一参数的变化所带来的经济效益进行评价；给出桥面铺装层设计构造建议。

A factor of friction power is considered during fatigue, and a new model for predicting fretting fatigue life under low cycle load is presented based on a nominal stress method. For dovetail joint, the problem of elastic contact is solved using the finite element method.

在低周疲劳寿命预测方法中，通过引人摩擦功因子，考虑微动作用对构件疲劳寿命的影响，对传统的名义应力法进行改进，以用于构件的低周疲劳寿命预测。

Manufactures and markets test equipment products include: Programmable constant temperature and humidity testing machine, constant temperature and humidity box, high and low temperature testing machine, high-temperature box, cold temperature testing machine, hot and cold impact testing machine, the temperature cycling chamber, salt spray test machine, corrosion test chamber, the aging test machine, a large environmental test chamber, high temperature aging rooms, environmental test chamber, UV weathering test chamber, vibration, drop test machine, temperature water tank, clamshell laptop life testing machine, keyslife testing machine, testing machine drop life test simulation environment test equipment.

伟煌试验设备有限公司生产和销售的产品包括：可程式恒温恒湿试验机，恒温恒湿箱，高低温试验机，高低温箱，低温耐寒试验机，冷热冲击试验机，温度循环试验箱，盐水喷雾试验机，耐腐蚀试验箱，老化试验机，大型环境试验室，高温老化房，环境试验室，紫外线耐候试验箱，振动，跌落试验机，恒温水槽，笔记本翻盖寿命测试机，按键寿命测试机，跌落寿命测试试验机等模拟环境试验设备。

By mechanical analyzing the shaft of supporting wheel, the relation between the axis line and fatigue fate of support system is derived.

本文通过对回转窑托轮轴进行力学分析，导出支承系统各托轮轴疲劳损伤与轴线偏差的关系，从而根据轴线检测得出各托轮轴剩余疲劳寿命；以轴线偏差调整量为优化变量，各托轮轴中最小的剩余寿命最大为目标函数建立优化模型，结合现场实例进行支承系统等寿命优化调整研究。

The characteristics of fatigue life curve of materials in three stages of fatigue life were analyzed and then a model with three parameters was presented to describe the fatigue life curve of materials in the whole region.

分析了材料疲劳寿命曲线在三个阶段内的变化特性，提出了一个描述材料全寿命区域内疲劳寿命曲线的三参数模型。

Finally, the service life of the valve was estimated based on the fatigue life curve and an improvement of the valve structure was also presented, it could effectively alleviate the stress concentration and prolong the service life.

依据泵阀疲劳寿命曲线，对泵阀使用寿命进行估算，并提出一种泵阀结构改进的新方案，在一定程度上有效减缓了应力集中，对延长泵阀使用寿命具有重要的实用价值。

These are references of theory and test for safety assess of reactors. The paper put forward the concept of decrease coefficient , and the actual calculation process of K〓 for forecasting the fatigue life of the structure. The research made it possible to forecast the fatigue life of damaged materials, and the prediction was based on the S-N curve from the fatigue test of the smooth material with controlled strain.

提出了疲劳寿命的减少系数K〓的概念，给出了计算K〓预测结构的疲劳寿命的具体过程，这一问题的研究使以平滑材料控制应变疲劳试验得出的S-N曲线图为基础来预测有损伤材料的疲劳寿命成为可能。

Based on gun bore radial wear Δdmax as discrimination condition of barrel life the mathematical model for predicting melt-erosion of gun-barrel is established which is employed in analyzing factors affecting the life of gun such as material, gun powder,firing conditions and so on. It is pointed out that active cooling technology is an effective method for solving many problems concerned with heat transfer each time the gun is fired.

文中由身管寿命判别条件△d_建立了身管熔化烧蚀预测计算模型，从原理上对各种延缓烧蚀速度、提高身管寿命的措施，如采用内膛镀铬、使用冷火药和护膛剂等进行了阐述；同时基于该模型指出采用身管主动冷却技术是延长火炮身管寿命最有效的措施之一。

Properties of the castables,rammed materials and gunning materials used in the iron runner of large scale blast furnaces are studied and relationship among the material properties,working processes and service life analyzed.

对大型高炉出铁沟用浇注料、捣打料、喷补料的性能进行了研究，分析了材料的性能、施工工艺与使用寿命的关系，认为适当的维护对于降低成本、提高寿命是有益的，铁厂需要合理的考虑使用寿命与材料的价格因素。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失