交变载荷

The cyclic loading not only affect the inner part of the material but also the surface state of the corroding surface.

交变载荷不但影响了材料的内部，同时也影响了腐蚀表面的表面状态。

Due to slope cable bears barely alternative load longtime in nature environment, it is easy to corrosion and wreck. Seriously, the bridge is possibility to collapse in strictness air empoison, water pollution, seashore and ocean surroundings. Therefore, to study cable's corrosion widely and to inhibit corrosion process are very important for increase endurance and safety of bridge construction.

由于斜拉索长期承受交变载荷并暴露于自然环境中，特别是大气污染严重地区、水污染严重地区、海滨及海洋环境，极易发生腐蚀破坏，严重者还会因坍塌而造成生命及财产的巨大损失，因此，全面研究桥梁拉索的腐蚀，阻断腐蚀的成因，对提高桥梁结构的耐久性与安全性具有重要意义。

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。

The high-speed and multicycle impact characteristics of an automotive chain differ from other high-speed roller chain. The double effect of multicycle impact characteristics and speed, load fluctuant characteristics set up a stern claim of wear to automotive chain.

汽车链条的高速多冲特性不同于其它高速滚子链，高速下的多冲特性以及速度与载荷交变特性的双重效应，对其耐磨性能提出了苛刻的要求，而速度与载荷交变特性的影响尤为重要。

The mechanisms and mechanical components in general use are mostly used long-term and recurrently , and most of these mechanical components bear long-term loads and alternate loads .

普遍应用的机械，设备和机械构件，一般都是长期使用和循环使用的，运动部件大多承担长期交变载荷。

2 What is the maximum allowable stress for CJP groove weld meta l splicing two ASTM A-36 steel non-redundant members of equal thickness and width, subject to loading of 2×106 life time stress reversals, assuming the weld reinforcement remains and all such joints are to be radiographed ?

对於连续两个同样厚度和宽度的 ASTM A-36钢的非超静定焊接件，假定保持焊缝加强高并所有如此接头都要进行射线探伤，在承受2×106连续应力交变载荷下完全熔透坡口焊缝金属的最大允许应力是多少？

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。

It is considered that fatigue crack is early produced on drill pipes, because the vibration load of drilling tools in air drilling is more severe than that in mud drilling. Fatigue cracks easily occur under alternating vibration. Because the current wellhead detecting instruments can not be used to reflect the change of pump pressure produced after drill pipe piercement timely and accurately, effective measures can not be taken in time to prevent the expansion of fatigue cracks. As a result, drill pipe fracture accidents occur.

失效分析表明，钻杆属于早期疲劳断裂，断裂主要原因是在空气钻井过程中钻具受到的震动载荷远大于钻井液钻井过程中的震动载荷，在交变的震动载荷作用下，钻具容易产生疲劳裂纹；由于现有的井口检测仪表不能精确及时反映钻杆刺穿之后产生的泵压变化，无法及时采取预防措施，疲劳裂纹不断扩展，最终导致了钻杆断裂失效。

Based on the design and calculation methods for common tight joint bolt, which is subjected to the changing load, a design and calculation methods for flexible bolt is given.

在普通承受交变载荷紧螺栓连接设计计算方法的基础上，给出了采用柔性螺栓的设计计算方法和公式，并以某型柴油机气缸盖螺栓为例，进行了改用柔性缸盖螺栓的设计计算。

The spring element is one key part of DMF.

弹性元件是DMF的关键部件之一，本文的主要工作是分析在交变载荷下弹簧的应力和疲劳寿命。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。