裂纹

If θ=0?＃, it means that whisker axis is perpendicular to crack face, the energy dissipation caused by whisker-bridge join in zone of crack end achieves its maximum and the reintoughening effect of material achieves the best of all; along with growth of angle θ, the maximum principal stress in the matrix of whisker roots increases, when it achieves its limit, the whisker will be broken and orientation effect will be weakened.

当添加晶须与裂纹面法向形成角度θ时，随角度θ的增加，裂纹尖端拉应力增加。当添加角度较大时，晶须根部基体承受了较大的应力，易遭到破坏性崩裂。同时，晶须内部主应力与晶须轴向之间的角度也随角度θ的增加而增加，造成晶须折断，致使造成晶须拨出的体积分数φap减小，降低了增韧效果。

The second principal normal stresses can lead to grinding crack which generates forward beneath the abrasive grain in the plane of grain motion.

在磨粒前下方，受第二主应力的作用，磨削裂纹主要沿磨削方向开裂；在磨粒后方，受第一主应力的作用，产生垂直磨削方向的磨削裂纹。

Studyed the analytical model of buried pipeline and suspending pipeline, introduced a factor about the redistribution of deflection and moment of suspending pipeline, rasied a analytical model between deflection and moment, showed that the deflection

3分析管道裂纹形式和种类，探讨脆性断裂和延性断裂失效判据及其适用条件，对裂纹扩展进行应力-应变场分析，建立了适合本研究课题的应力-应变场模型。

On the basis of the principles and structures of the cold cracking implant testing machine,the study on the implant equipment of reheat cracking test is reviewed in this paper.

在深入分析冷裂纹插销试验机的原理和结构的基础上，本文进行了插销式再热裂纹试验装置的研究工作。

Orthogonal experiment under special condition showed that modifier M has marked effect on properties of no bake sand. Other factors such as modifier B,phosphate concentration and aluminum hydroxide have some impact on properties of binder. It can be found by experiments that strengths of no bake sand are raised notably by binder that modified by modifier B. Modifier B can reduce the strength of no bake sand at high room temperature apart from condition of low room temperature that it can accelerate the reaction and strengthen the sand. Modest content of modifier M in binder has some improvement to anti-wettability of sand. But modifier B has not such notable effect. Electronic microscope shows that near cracks in no bake product there are fibrous shape substances formed when the samples are moistured in high humidity air for sometime.

通过改性剂B对粘结剂自硬砂的性能影响试验发现，改性剂B能显著提高粘结剂自硬砂的强度，在0℃左右很低的环境温度下改性剂M有利于提高自硬砂的反应速度和砂型强度外，但在较高环境温度下，改性剂M均降低粘结剂自硬砂的强度，但是适量的改性剂M有利于改善自硬砂的抗吸湿性，而改性剂B对于改善自硬砂的抗吸湿性的作用不如改性剂M明显，电镜观察发现抗吸湿性较好的自硬砂在高湿度下存放一定时间后，在粘结膜裂纹处会形成一种绒毛状物质，该物质对裂纹具有愈合作用，这种绒毛状物质中具有改性剂M中的某种成分，且含量很高，由此说明改性剂M对提高抗吸湿性有利。

Therefore, grinding cracks, subsurface scathe and machining parameter's effect to are worthwhile to be studied.

因此，研究磨削裂纹、尤其是亚表面微裂纹的形成与扩展，及其与加工参数的关系；具有重大的现实意义。

Some meaningful conclusions had been made: 1. In the test, a form of subsurface crack is relative to the sclerometer's shape, when the top of the sclerometer is sharper the crack is easier form.

在该划痕试验中，亚表面裂纹与压头本身的形状有关；当压头顶部较尖锐时，在划痕深度一定的条件下，更容易产生裂纹； 2。

The results make it known that: in the same cycle degree, the crack propagation depth of finite element is greater than experiments, the inaccuracy between expriments and computer simulation tracing is lower than 10%, the tracing conclusion is securer than the experimental one; both directions of crack propagation are not identical.

当接管区出现裂纹时，则在疲劳载荷的作用下会加速扩展，从而降低设备的使用寿命，并且可能发生一些毫无征兆的事故。因而研究并掌握接管区表面裂纹的疲劳扩展特性对于预防接管区的失效破坏具有一定的学术和工程价值。

The results showed that most multiaxial fatigue cracks were initiated and propagated along the direction of maximum shear plane.

利用扫描电镜对疲劳试样的外表面和疲劳断口进行观察，研究了多轴疲劳裂纹萌生和扩展规律，发现裂纹基本上沿着最大剪切平面萌生和扩展。

Crack can be continuous, or random, may appear in the side of the adhesive materials drum, or it might have, so both sides, pressure-sensitive material on mechanism of cards and membership cards before, it examined adventitious to the backing sheet and the glossy paper on small cracks.

裂纹的发生可能是连续的，也可能是随机的，可能出现在卷筒不干胶材料的一边，也可能两边都有，所以，不干胶材料上机制卡和会员卡制作前，不定要仔细察看其底纸和面纸上是否有小的裂纹。

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。