疲劳

Base on the problem of large quantity fatigue loads on corroded R.C. structure and small quantity study of its mechanical property, bending resistance fatigue test of corroded R.C. beams is discussed in this paper. The influence of stress ratio and re-bar weight loss ratio on bending resistance fatigue performance of corroded R.C. beams are researched, and the relation between strains of corroded re-bars and fatigue life of beams are obtained. The main research contents and conclusions are as following: 1. Under the fatigue loads, the overstrain of concrete approximately coincidences three stages strain development and accumulation rule, and the mechanical property of concrete is deteriorated. The fatigue damage of concrete is accumulated. The overstrain of re-bars increases and the increase rate decreases.

鉴于实际工程中大量存在腐蚀钢筋混凝土结构承受反复荷载作用，但其力学性能研究不多的问题，本论文进行了锈蚀钢筋混凝土梁抗弯疲劳试验，研究了应力比和钢筋锈蚀率对锈蚀钢筋混凝土梁抗弯疲劳性能的影响，得出了锈蚀钢筋的应变与构件疲劳寿命之间的关系曲线，主要研究内容及结论如下：(1)在循环荷载下，混凝土残余变形基本符合三阶段变形规律，力学性能劣化，疲劳损伤积累。

To the question of fatigue invalidating of strain gages in dynamic test(normally the zero drift value being bigger than the permissible value),the equations for calculating the fatigue life of the strain gages are derived on the basis of the fracture mechanics theory.

针对应变片在长时间的动态测试中疲劳失效(一般是测量误差超过允许值)问题，本文从疲劳断裂力学的基本理论出发，导出了应变片疲劳寿命的计算公式；实验表明，实验曲线与理论曲线吻合，这证明我们推导的公式的正确性，为应变片的疲劳寿命的预测、许可载荷的确定、失效判据的确立提供了理论基础。

In this paper, thermograph method which has merits such as accuracy, short time, convenience and economy is applied to determine the fatigue limit of 45# steel from the temperature change, and the heat generation mechanism that resulted in temperature change during the fatigue was researched on.

文中利用具有准确、快速、便捷、低成本等优点的红外热像仪测量了45#钢疲劳过程中的温度变化，对疲劳过程中引起温升的机制进行了探讨，通过对试验数据的分析，实测值在疲劳极限估算值范围内，快速确定了45#钢的疲劳极限。

The effect of undissolved ferrite amount on contact, impact and bending fatigue properties were studied. The stress relaxation and grain refinement due to occurring of plastic deformation are main reasons of improving the fatigue life.

就未溶铁素体含量对接触疲劳、多冲疲劳及弯曲疲劳性能的影响机理进行研究，局部的应力集中因铁素体发生塑变而得到松弛和细化晶粒是提高疲劳寿命的主要原因。

So the braking prescription should be performed strictly, furthermore, the sudden and urgent braking should be avoided to the best of our abilities.In the end, the thermal fatigue lives were evaluated by the finite element method. It was proved that the thermal fatigue life of improved steel (ZG35CrMoRE) was higher than that of the formers. It was also found that the quantitative evaluations of the thermal fatigue lives of brake disc were acquirable, by putting the equivalent plastic strain, which was analyzed with finite element methods, and the material mechanical property parameters into the formula of Manson-Coffon to calculate its lives. Therefore, theoretical method can be provided to develop new brake disc steel and to prolong its lives.

为了进一步提高刹车鼓的使用寿命，对新试制的钢种进行了热疲劳寿命评估，验证了改进后的钢种在相同的使用工况下具有更高的热疲劳寿命；评估结果还表明利用有限元数值分析计算相应的等效塑性应变，结合材料力学性能参数，代入Manson-Coffin热疲劳寿命公式可以对刹车鼓的热疲劳寿命做出定量评估，从而为刹车鼓用钢的研制和刹车鼓寿命的提高提供了理论依据。

Firstly, achieving a new low and high cycle noninterfering loading, the high frequency induction local heating, the control of high cycle vibration frequency and amplitude, and the crack propagation real-time detection, an experimental system of L-HCCF at elevated temperature is established. Secondly, under two vibration frequency (50Hz and 100Hz), the contrast experiment of light and serious corrosion disc slots is done. It is found that the experimental L-HCCF life of serious corrosion disc is less than that of light's, but its dispersion is larger, and the experimental failure is identical with the service's.

首先，进行大量试验工作，提出了高低周疲劳载荷的新型加载方案，并解决了高频感应局部加温、振动调频及裂纹实时监测等多个技术难点，建立了涡轮盘全尺寸高温复合疲劳试验系统；验证试验做到了故障再现；接着进行了两种频比（振频50HZ与100HZ）的轻、重腐蚀盘的对比试验；由对榫槽第一齿进行裂纹实时跟踪，得出了枞树型榫槽的复合疲劳裂纹扩展特点规律；对榫齿断口进行的金相分析表明：裂纹首先由第一齿开始，断口系复合疲劳；试验结果显示：重腐蚀盘试验寿命较轻腐蚀盘有显著的下降，而且分散性较大。

In order to describe the fatigue damage characteristic under multiaxial proportional and nonproportional loading, a new nonlinear multiaxial fatigue damage cumulative model was presented on the basis of combining multiaxial fatigue damage characteristic. The recurrence formula of multiaxial fatigue damage model was derived under multilevel loading.

为了描述多轴比例与非比例加载下的疲劳损伤特性，结合多轴疲劳损伤的特点，建立了一种新的非线性多轴疲劳损伤累积模型，并推导给出了该疲劳损伤累积模型在多级加载条件下的递推公式。

The integrate evaluation by using multiple indicator mentioned above can reflect the change of sports load and athletes' functional status and the degree of the sports fatigue comprehensively and sensitively, can offer quantified scientific basis to diagnose the sports fatigue by the combination of Chinese and western medicine. It is also very important to control training load, judge sports fatigue, prevent overtiredness and development of sports injury to excavate demic sports potential efficaciously, raise contest ability etc, and has become all important part of scientific training.

用上述指标进行综合评定，能较灵敏地反映运动负荷量的变化和运动员的机能状态及运动性疲劳程度，为中西医结合诊断运动性疲劳提供科学依据；同时对控制训练负荷，判断运动疲劳，防止过度疲劳和运动损伤的发生，有效地挖掘人体的运动潜力，提高竞技能力等，均有十分重要的意义，并已成为科学训练的重要环节。

It presents test results of performance for three structural types of cement stabilized macadam including suspend-dense structure framework-dense structure and framework-pore structure, for two structural types of lime fly-ash macadam including suspend-dense structure and framework-dense structure, and for cement stabilized soil. By the probability analysis of Weibull on the results of fatigue test, the paper has a serial of fatigue prefigurative models. What's more, amends these models linking to the factual pavement performance.

在对三种结构的水泥稳定碎石(悬浮密实结构、骨架密实结构、骨架空隙结构)、两种结构的二灰稳定碎石(悬浮密实结构、骨架密实结构)、均匀密实结构的水泥稳定细料土进行室内三分点加载疲劳试验的基础上，采用威布尔分布理论对疲劳数据进行处理，得到各自的室内疲劳预估模型，并结合实际路面的情况对室内疲劳预估模型进行修正。

Tension-tension fatigue experiment was carried out at three different stress-level, the fatigue life and the S-N curve of the unnotched laminates were acquired.

进行了三种不同应力水平下的拉-拉疲劳试验，得到无孔试件的疲劳寿命及其S-N曲线；通过研究复合材料疲劳寿命预测的方法，建立了该无孔层合板剩余刚度疲劳累积损伤寿命预测模型。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了