疲劳

The contact fatigue strength was measured after the 20CrNi2Mo and 15CrNi6 steel used asdragging gear on quasi high speed locomotive was carburized and quenched as well as peened,com-pared with that of 20CrMnMo steel.The results shown that the contact fatigue strength limits of thesethree types of steel carburized and quenched essentially same,and the contact fatigue strength Iimit hasbeen increased by 5 porcent after peening,and that the failure appoarances of all contact fatiguespecimen were delamination ...

对20CRrNi2Mo、15CrNi6及20CrMnMo渗碳淬火齿轮及15CrNi6渗碳淬火＋喷丸处理齿轮进行了弯曲疲劳试验，介绍了齿轮试件的设计与加工、试验装置与夹具、试验方法及试验数据的统计处理，试验结果表明，20CrNi2Mo和15CrNi6渗碳淬火齿轮在R＝0.99时的σFlim分别为530MPa和375MPa，与20CrMnMo渗碳淬火齿轮相比，弯曲疲劳强度分别提高80％和27％。15CrNi6经渗碳淬火＋喷丸处理齿轮在R＝0.99时的σFlim为490MPa，比未喷丸处理者提高30％。

The stress analysis and the fatigue life loss calculation of steam drum are carried out in this article. A simplification formula is proponed to calculate the main stress and is used in configuration of DCS. The rain-flow method is used to count the fatigue cycle, which can satisfy the need of on-line monitoring.

本文对其进行了应力分析和疲劳寿命损耗的计算，并提出主应力计算的简化公式用于DCS组态，采用雨流法作为在线计算的疲劳计数方法，满足了寿命损耗在线监测的要求。

In the coating, the nodular defect was observed to worsen severely the properties. For testing under oxidation condition, the nodular defect results in the internal oxidation of Al. No single Al oxide scale may be formed at 1100℃ owing to consumption of Al. Under hot corrosion, it becomes as short-path for diffusion of S through the coating, thus sulphuring the coating together with the substrate. During thermal shock testing, it may act as the source of cracking, and moreover, if cyclic stress applied, the cracks propagate toward the substrate, the thermal fatigue properties of coating will be worsened.

结果表明：在氧化条件下，缺陷导致Al的内氧化，在1100℃时，由于Al的大量内消耗，涂层表面已不能形成单一的氧化铝膜，使氧化性能下降；在热腐蚀条件下，缺陷成为硫向涂层中扩散的通道，导致涂层及基体的硫化；在冷热疲劳条件下，缺陷成为裂纹源，在交变应力作用下，裂纹向基体中扩展，降低了涂层的热疲劳性能。

This research method is to use the three-dimensional mapping software to draw the cardiovascular stent of different size first , next is it create their cardiovascular stent boundary conditions and simulation their of support after implantation according to finite element method into the human body to go; Receive different residue pressures and pressure of the repeated blood circulation , greatest stress , meets an emergency and the relation between total deformation amount caused; Being imitated the cardiovascular stent , the position with damage of fatigue life in the blood vessel by its greatest stress value at the same time ; But by the simulation result of the above , can understand that use life of Palmaz-schatz cardiovascular stent has been more than 109 up till now ; At the same time , can know the position where the stress two times concentrates , the right angle position joined in the rib and rib of Palmaz-schatz cardiovascular stent too.

本研究的方法乃是先会使用三维绘图软体画出不同尺寸的血管支架，然后在根据有限元素法去设定其血管支架的边界条件和模拟其植入人体后；受到不同的残留压力与反覆血液流动的压力，所造成的最大应力、应变及总变形量之间的关系；同时在由其最大应力值去模拟血管支架，在血管中的疲劳寿命与疲劳损坏位置；然而由以上的模拟结果，可以了解到目前Palmaz-schatz血管支架之使用寿命为109以上；同时也可以知道二次应力集中的位置，在Palmaz-schatz血管支架之肋和肋连接的直角位置。

The time used to swim reflects the fatigue level of animal during exercise, while the time used to climb a pole reflects the fatigue level of animal during exertion of force.

游泳时间的长短可以反应动物运动疲劳的程度，而爬杆时间的长短可以反应动物静用力时疲劳的程度。

Based upon the experimental results, including threshold values under static loading,the effects of alternating loading and room temperature creep,as well as metallographic observations of the fractography,it is concluded that notwithstanding stress corrosion or corrosion fatigue in aqua ammoniae,or fatigue in air,the cracks always initiate at the site subject to maximum normal stress(θ=-110°)along the notched surface,and then propagate along the maximum shear stress direction from that site(α=-35°).

由门槛值的测量、交变载荷的作用、室温蠕变的影响、断裂过程的金相观察及断口形貌等结果，可以确认；黄铜不论是在氨水中应力腐蚀或腐蚀疲劳，还是在空气中疲劳，裂纹都从Ⅱ型缺口试样的最大正应力处(0=-110°)萌生，并沿该处的最大剪应力方向(α=-35°)扩展。

Change tradition tee joint into abutment joint , resulting in clear increase of fatigue strength of welding line of oscillating axle of press and safety service life of press hence a worthwhile method for corresponding personnel .

文章提出了提高压力机的摇摆轴焊缝的疲劳强度的技术措施，即将传统的在光轴上的&T&形接头改为台阶轴上的对接接头，可显著提高压力机的摇摆轴焊缝的疲劳强度及压力机的安全使用寿命，此方法值得有关人员借鉴。

On this basis and by using correspondent fatigue criteria, fatigue life prediction of steel box girder of bridge was discussed.

利用标准日应力谱数据和相关疲劳规范，研究了杨浦大桥钢箱梁的疲劳寿命等问题。

For steel box girder of Yangpu Bridge, fatigue stress monitoring and fatigue life prediction were implemented.

针对杨浦大桥钢箱梁，进行了疲劳应力的监测分析和疲劳寿命的预测研究。

The factors to influence fatigue life of chain plate are concluded by experimental methods.

用试验方法确定了挤孔对链板疲劳寿命的影响，从理论上分析了在最佳挤孔量下，链板疲劳寿命提高的因素，用有限元法计算了 16 A链板的最佳挤孔量，并与试验结果进行了比较。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。