疲劳强度

Results of analysis show that Generalized Paris Law can consider the complex crack propagation in the material of the pavement structure. The fatigue life of the pavement increases with increasing thickness of surface layer in a power function. Use of a thicker surface layer may extend the service life of the asphalt pavement. The fatigue life increases with decreasing modulus of surface layer in a power function with a negative exponent. However, since reduced modulus would scarify the structural strength and might cause rutting-related distress, caution should be taken when using low modulus materials for improving fatigue performance of asphalt pavements. The fatigue life increases with increasing modulus of base material in a power function. However, the fatigue life can not infinitely increases with increasing modulus of the base.

计算与分析表明：广义Paris公式可以考虑沥青路面结构内材料复杂的裂缝扩展：沥青面层的疲劳寿命随着面层厚度的增加以幂函数的形式增加，适当增加沥青面层厚度可以提高路面的使用寿命；沥青面层的疲劳寿命随着面层材料模量的降低以负指数的幂函数形式增加；由于材料模量的降低将牺牲路面的整体强度并可能引起路面车辙类损坏，以此提高疲劳寿命的方法应慎重对待；沥青面层的疲劳寿命随着基层材料模量的增加呈幂函数的形式增加，但由疲劳方程可以看出，寿命并不是随基层材料模量的增加而无限的增加，疲劳曲线在经过一个上升段后，逐渐趋于一个常数值，这说明，这时基层模量对寿命已不作关键性贡献；随着底基层厚度的增加，面层的疲劳寿命近似地呈线性函数增加，但效果并不很明显。

The results in this paper are concluded as follows:(1) Rolling contact fatigue has been used to examine the interfacial reaction products and study the mechanism of ion beam intermixing effect on the adhesion of Cr-N coating on steel by IBAD.

对多次冲击条件下薄膜的失效抗力及其与薄膜力学性能之间的关系进行了初步探讨，得到如下结果：（1）用滚动接触疲劳法检测离子轰击导致的界面反应产物和研究离子束共混对钢基体上IBAD沉积Cr-N薄膜结合强度的影响本质，结果表明，滚动接触疲劳能有效地分析界面最薄弱位置和评估界面反应产物，滚动接触疲劳引起的剥落可作为研究界面反应产物对结合强度影响的根据。

The paper deals with the fatigue strength,lifetime prediction and its influences of the valve spring steel wires .

讨论气门弹簧钢丝的疲劳强度、寿命预测及其影响因素。

The transition of S-N curve from the former to the later is almost continuous.

前者的S-N曲线向后者的转移几乎是连续的，回火温度对疲劳强度和寿命没有明显的影响。

The friction between teeth of light-load precision involute spur gearing mechanism was studied by using of the line-contact isothermal EHL under the condition of the well-lubricating.

运用线接触等温弹流理论详细考察了精密轻载渐开线圆柱直齿轮在润滑良好情况下的齿间摩擦力，研究结果表明良好的润滑会使齿间摩擦对轮齿弯曲疲劳强度的影响显著降低但仍然不可忽视。

Longer fatigue life is the key point for spring steel with ultimate tensile strength of 2 000 N/mm2 grade.

提高齿轮钢的强度需要改善其抗疲劳性能；1200N/mm2螺栓钢和2000N/mm2弹簧钢的强度需要改善抗延迟断裂性能和抗疲劳性能；提高微合金非调质钢的强度需要改善其韧性。

Throught several powerful shot peening contrast tests of carbonitriding gears,the effect of powerful shot peening with different parameter,and the influence of low temperature tempering to contact fatigue strength of bearing surface were researched.

通过对碳氮共渗齿轮试片进行了多次强力喷丸试验，研究了不同喷丸参数下的强力喷丸的效果及喷丸后的低温回火处理对提高齿轮试片表面接触疲劳强度的影响。

Based on the analysis of the theory and technology, a torsion bar mechanism is adopted to measure the moment of inertia, which has good elasticity, largeaccumulated energy characteristic, high fatigue strength resistance, a large range, high accuracy and so on.

在分析转动惯量相关测量理论和测量技术的基础上，设计了一种新颖的扭杆结构，这种结构具有弹性好、储能大、抗疲劳强度高、测量范围大、测量精度高等特点。

In addition, dislocations are also different in three kinds of samples under TEM.

上述特征都预示低载锻炼后，结构的疲劳强度得到了提高。

At present the major problem with the application of ductile iron crankshaft s is that their fatigue strength is not enough to meet requirements raised due to the everincreasing of the explosion pressure of engines, as well as the quality of ductile iron castings is not stable.

目前球铁曲轴应用中存在的主要问题是疲劳强度满足不了发动机爆发压力不断提高的要求，以及球铁质量不够稳定。

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