疲劳强度

The rubber seal issue under operating system has been studied by the theory of dynamic sealing. The deformation and stress distribution of rubber material were calculated under the well in-pressure and sealing out-pressure using then-linear finite element. Through the experimental study of the rubber strength and fatigue, the intensity limit and the fatigue life were obtained. According to the study results, a new type of sealing equipment was designed by adding the reinforcing steel bar into rubber core to reduce the maximum shear stress, so as to solve the problems of dynamic seal under hyperbaric pressure.

采用动态密封理论，针对带压作业系统中的橡胶密封胶芯问题，利用非线性有限元计算了在井压和密封外压作用下的变形和应力分布特征，并通过对密封胶芯材料进行了强度和疲劳实验研究，获得了胶芯材料破坏的原因，进而根据计算和实验研究结果，进一步提出了在胶芯内增加钢筋以减小最大剪切力的改进意见，同时进行了理论校核，并以此为基础设计了新型的密封胶芯，从而解决了带压作业装置高压动密封的难题。

The influence of strength level and surface strengthening of 5CrNiMo steel on the impact fatigue property in the range of hardness required by hot drop-forging die steel is investigated.

研究了5CrNiMo钢在热锻模要求的硬度范围内，材料强度水平和表面强化对冲击疲劳性能的影响。

Therefore, considering wide-range and importance of the box-sectioned welded beam applied in engineering, the author chooses this structure as one of typical welded structures to study. And with the equalizing bar of a bulldozer as an example, the method of fatigue design or life prediction and interrelated data of the box-sectioned welded beam are achieved through systematic study, and are considered as the basis of the structure fatigue design code or guideline which is expected to apply in machinery industry.

基于焊接箱形梁使用的广泛性和重要性，作者选择此种结构作为典型焊接结构的研究对象，并以推土机平衡梁为例，通过系统研究获得了结构疲劳设计或寿命预测方法及有关数据，作为形成结构动强度设计规范的基础，并由此可进行推广应用。

The forms of fatigue cracks in bore of gun barrel are considered as edge cracks and semi-elliptical cracks. The stress intensity factors of gun barrel are calculated using a weight function method under the autofrettaged residual stress, thermal stress and assemblage stress.

3武器身管内表面的疲劳裂纹考虑为边裂纹和半椭圆型表面裂纹两种形式，用权函数方法研究了身管在自紧残余应力、温度应力和装配应力作用下的应力强度因子。

The fatigue analysis also was carried out with FE-SAFEWORKS then the fatigue life was predicted. A new way of design of coupling shaft is proposed.

基于此，应用有限元方法分析了转接轴静强度，并用FE-SAFEWORKS模块对转接轴进行疲劳分析，计算其寿命，从而为转接轴的设计提供一种新的思路。

The process of dynamic fatigue damage accumulation was discussed based on residual strain intensity theory and linear degradation criterion.

基于剩余应变强度理论和线性退化准则讨论了断续节理岩体动态疲劳损伤累积过程。

High strength, high elasticity, strong sticking, age resistant, vibration fatigue resistant, can polish and spray on the surface.

高强度、高弹性、粘接力极强。耐老化、耐振动疲劳，表面可打磨、喷漆。广泛用于车

Its strength is higher than carbon fiber, and its quality is lower than carbon fiber and glass fiber.

它的强度比碳纤维高，密度比玻璃纤维、碳纤维都小，热膨胀系数低，抗疲劳性好，在一些特殊的应用领域里具有不可替代的作用。

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。