裂纹

The object of the present paper was to study the relationship between corrosion fatigue crack growth rate da/dN and stress intensity factor amplitude ΔK of 07MnNiCrMoVDR steel by corrosion fatigue crack growth rate experiment in H2S solution. This steel is the typical material used in chemistry and oil chemistry equipment in our country. Corrosion fatigue safety assessment method of pressure vessels with defects in service could be explored and investigated.

本文研究通过对我国化工和石油化工装置中的典型材料07MnNiCrMoVDR钢在腐蚀介质H2S水溶液中疲劳裂纹扩展速率的研究，寻找其腐蚀疲劳裂纹扩展速率da/dN和应力强度因子幅值ΔK之间的关系，探索研究在役含缺陷压力容器腐蚀疲劳安全评定技术。

The stress intensity factors of surface crack with various inclined angle subjected to normal and shear contact loadings are obtained.

文中算例分析了不同倾角的表面裂纹在法向和切向接触载荷作用下，裂纹尖端的应力强度因子。

And then, take a 样纸 of the above checks, you peel to the backing sheet paper and again check the backing sheet on crack, because crack sometimes is a very small, only separated from the backing sheet and paper before it can be found.

然后，取一段经过上述检查的样纸，剥于底纸再次检查一下面纸和底纸上是否有裂纹，因为裂纹有时是非常小的，只有分开底纸和面纸后才能发现。

The influence of different locations and depths of crack on nonlinear vibration behaviors for the cracked main beam of bridge was analyzed by the numerical calculation.

通过数值计算，分析了裂纹的位置和深度的变化对车桥耦合系统中含裂纹主桥的非线形动力特性的影响。

This paper analyses the longitudinal crack on the near net shape beam blank web surface in Laigang, gives the influencing factors and improved measures.

对近终形异型坯腹板表面纵向裂纹问题进行了分析，找出了工艺和设备方面的影响因素，通过对钢水质量、冷却条件、设备结构等方面进行优化改进，解决了铸坯表面裂纹缺陷问题，铸坯质量合格率由94%提高到99.5%。

Under compressive stresses, tensional failure will occur in the rock bridge of the end of joint, which leads to connect new cracks of rock bridge with the nearby primary joints.

当节理在压应力作用下所产生的次生裂纹扩展达到相邻节理后，岩体就会产生贯通裂纹而破坏。

The mechanical effect of the crack initiation and propagation under a residual stress field is analyzed, and then the residual stress redistribution because of cracking in the welded residual stress field in a plate butt welded joint is successfully calculated by means of the elasto-plastic finite element method .

分析了在残余应力场中裂纹产生和扩展所引起的力学效应，并成功地运用弹塑性有限元方法计算了平板对接接头焊接残余应力场中裂纹扩展引起残余应力的变化。

In the paper,the cause and treatment technology for the connection welding seam crackle defects of the bucket sharft flange and bucket sharft of the coal yard bucket stacker/reclaimer of a 660 MW thermal power plant are introduced.

针对某火力发电厂660MW机组燃料煤场斗轮堆取料机的斗轮轴法兰与斗轮轴连接焊缝裂纹缺陷，对产生裂纹的原因及处理工艺进行了分析和论述，制定了处理措施及焊接工艺。

In situ comparison of surface slip deformations showed that the persistent slip bands emerging at the surface was delayed, and the surface deformation homogenized after implantation, an indication of ductility improvement.

各离子注入使试样表面的变形分布更均匀，推迟了PSB's在表面的出现，表明离子注入延长了试样的裂纹萌生寿命。而疲劳断口分析表明，各金属离子注入对裂纹的扩展过程无明显影响。

By measuring the residual stresses of the cylinder of a cement ball mill in four cases,and the fatique crack spreading for the thermal treatment and the un thermal treatment test samples,the results showed that the heat treatment sample reduced the residual stress,enhanced the fatique strength and lowered the crack spreading speed.

对球磨机筒体的4种情况的焊件进行残余应力测试，并对进行热处理和未进行热处理的试件做疲劳试验及疲劳裂纹扩展测试。试验结果表明：经过热处理的试件，残余应力降低，疲劳强度提高，裂纹扩展速率降低，结构抗疲劳性能增强。不过从工程应用角度看，对于板厚为20～25mm的球磨机筒体而言，不进行焊后热处理也能保证足够的疲劳强度

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。