疲劳强度

Because of their high tensile strength and good resistance against creep, fatigue and hot corrosion at elevated temperatures, nickel base superalloys are widely used for making the key components operating under the uncharitable conditions such as high temperature and high speed in aviation, power and petrochemical industries.

镍基高温合金具有良好的高温拉伸强度、高温蠕变抗力以及相当优异的抗高温疲劳和热腐蚀性能，广泛地用于制作航空、动力、石化等部门中承受高温、高速等苛刻工作条件的关键部件。

The corrosion fatigue crack growth and near-threshold characteristcsof high tensile steel HT60 were investigated by using the compact specimens underexposure to synthetic sea water. The da/dN vs △K_ relation in air may be conser-vetivel estimated for that in sea water. In the high △K region with high stressratio, owing to the acceleration of crack growth promoted by stress-induced dissol-ution, the crack opening stress intensity factor K_ represents only the result ofcrack surface in contact with corrosion products, so as to give an overestimation ofK_ at crack tip.

对高拉力钢HT60的腐蚀疲劳裂纹扩展特性和门槛值区域特性，采用紧凑拉伸试件在人工海水中进行了实验和研究，结果表明：在空气中的da/dN与ΔK_关系可以作为在海水中的da/dN与ΔK关系的一个偏保守的预测；在高应力比的高ΔK区域，由于应力诱起溶解促进了裂纹扩展的加速；该裂纹开口应力强度因子K_仅反映了裂纹表面同腐蚀生成物接触的结果，从而导致了K_在裂纹尖端的偏大的估计结果。

The mechanical autofrettage of thick-walled cylinders is a sort of practical and valuable technique used to enhan...

厚壁圆筒机械自紧技术是一项有实用价值的工艺技术，它可提高厚壁圆筒的弹性强度和疲劳寿命。

In this thesis, the second—order mechanical autofrettage technique is put forward and studied for the frist time.

它可提高厚壁圆筒的弹性强度和疲劳寿命。

The mechanical autofrettage of thick-walled cylinders is a sort of practical and valuable technique used to enhance its elastic strength of thick-walled tube and increase its fatigue life.

厚壁圆筒机械自紧技术是一项有实用价值的工艺技术，它可提高厚壁圆筒的弹性强度和疲劳寿命。

The change of plant diversity during natural recovery process of vegetation in Ziwuling area;2. Resource of Medicinal Plants of Caprifoliaceae and Its Utilization in Ziwuling Forest District of Gansu Province;3. Effects of Land Use on Soil Properties in Ziwuling Region

随着子午胎技术的不断进步，钢帘线厂家为满足轮胎使用厂商的要求，研制和生产了许多新型结构的钢帘线，且不断改善钢帘线质量，特别是在提高强度及改善抗锈蚀和耐疲劳性等方面有许多工作要做。

Near threshold fatigue crack growth tests were conducted under torsion on circumferentially pre--cracked round bars of a stainless steel.

研究了带环状预裂纹不锈钢圆棒试样在循环扭转载荷下、门槛值附近的疲劳裂纹扩展行为，用应力强度因子表征了裂纹扩展开始的门槛值。

Objective To investigate the intensity changes of different thickness ratios of Empress Ⅱ glass ceramic and GI-Ⅱ glass-infiltrated alumina ceramic before and after Hertzian contact cyclic fatigue.

目的 考察不同厚度配比的EmpressⅡ热压铸造陶瓷和GI-Ⅱ型氧化铝渗透陶瓷层状复合结构经Hertzian循环疲劳前后强度的变化。

The using instance of mould is complex, its always abated by abrasion, fatigue, or bad hot stability, and so on. To extend the longevity of mould, people try to use general heat treatment and other surface treatment, especially the gas nitriding, because of its inherent excellence, such as wearable、incohesive、co-fatigue、stand against permanence intensity and causticity under changeable load and so on, also the gas nitriding facility is cheapness, so the gas nitriding technics is abroad used.

为了提高模具的使用寿命，人们除了采用常规热处理外，各种表面强化技术也被广泛应用，特别是气体氮化工艺，因其能显著提高工件的耐磨性、抗擦伤性能、抗粘和性能、接触疲劳性能、冲击或交变载荷下的持久强度和耐腐蚀性能等，而且气体氮化工艺设备投资、生产成本低，更是被广泛关注。

Two multifunctional agent, glycidyl methacrylate and refined ricinoleic acid , were adopted to modify EPDM in situ during compounding and vulcanization process. The effects of the modifiers on vulcanization behavior, processiability, different properties of the vulcanizates were investigated.

为此，选择了含有极性基团的多官能团小分子改性剂甲基丙烯酸缩水甘油酯和精制蓖麻油酸，在橡胶混炼和硫化过程中对EPDM进行原位改性，研究了原位反应技术对过氧化物硫化EPDM橡胶的反应特性、加工性能、力学性能、热性能、耐老化性能、耐屈挠疲劳性能及与金属的粘合强度等性能的影响，并探讨了其改性的机理。

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。