裂纹

In this paper, the fracture behavior of nitramine propellant under different temperatures and crack lengthes has been studied through three methods, i.

本文用紧凑拉伸、三点弯曲和单边裂纹拉伸等三种实验方法对硝胺火药在不同温度和不同裂纹深度下的断裂性能进行了研究。

The fracture reasons of high strength PC steel wire are analyzed, it's considered that center segregation, central cavitation, poriness and inclusion are the metallurgical reasons which lead to the facture of PC steel wire and in the rolling process, differential coping quality, microcrack caused by surface defect, abnormal microstructure caused by burnt and improper cooling velocity, the ears on the head of the wire, overlapping of the wire rod itself are the main reasons which lead to the facture of PC steel wire. At the same time, inappropriate pickling, differential phosphorization quality, the bad heat treatment quality, the generation of crack in the improper drawing and transverse crack caused by abnormal laying of the drawing die are also the reasons of the cracking of PC wire.

对高强度PC钢丝断裂原因进行了分析，认为连铸坯的中心偏析、中心缩孔、疏松和夹杂是导致PC钢丝断裂的冶金原因；轧制过程中，较差的修磨质量、表面缺陷导致的微裂纹，过烧以及不适当的冷却速度导致的非正常显微组织，盘条头部的耳子、盘条本身折叠是导致PC钢丝断裂的主要原因；同时，不恰当的酸洗、较差的磷化及热处理质量、不适当拉丝裂纹的产生、拉拔模具安放不正导致的横裂也是PC钢丝断裂的原因。

All specimens were broken with brittle fractures under linear elastic plane strain conditions, and the extending di- rection of the cracks appeared to agree well with the three existing theories, e.g., the theory of maximum stress, the theory of ...

结果表明：复合型裂纹的脆断开裂方向与现有的三种复合型理论符合较好；但是，复合型裂纹扩展阻力随K_Ⅱ/K_Ⅰ比值增加而增大，与现有复合型理论差别较大。

It is known that the fatigue crack propagation rate is decidedby the stress-strain state of the crack tip at that time. According tolinear elastic Paris relation, this paper has suggested the three-point bendspecimen in which, from linear elastic to overall yielding ragions,da/dNis represented by the retation:da/dN=C_1~r.

由于疲劳裂纹扩展速率/决定于当时裂纹顶端附近的应力应变状态，本文根据线弹性范围内的Paris关系，提出三点弯曲试样在线弹性至全屈服范围内，/应服从下述关系：/=C_1~r。

Meanwhile a composite material has been used to simulate successfully the stochastical crack rock which was performed through adding crack blend, polytetrafluoroethyleneflakes, to geomechanical material.

同时，使用一种复合材料模拟了随机裂纹岩石，即通过将裂纹片掺合料，聚四氟乙烯薄片，加于地力学模拟材料而实现。

It is necessary to analyze the reasons that cause straint stress so as to prevent the weld from crack.

要防止产生裂纹，就要从仔细分析焊接时拘束应力产生的条件出发，达到防止产裂纹的目的。

According to the experience in the process of construction in recent years,the causes of wall surface cracking and the success and failure of the construction methods in the past are analyzed;and referring pertinent data and attempting to add sweller into the mortar which is used to masonry and plaster the wall surface so that the cracking can be balanced by the moderate swell of the mortar.

根据近几年施工中的经验，分析了墙面裂纹产生的原因以及以往施工方法的得失，查阅有关资料，尝试着在砌筑及抹面砂浆中掺加膨胀剂，以砂浆自身适度膨胀抵消收缩裂纹。

According to the experience in the process of construction in recent years,the causes of wall surface cracking and the success and failure of the construction methods in the past are analyzed;and referring pertinent data and attempting to add sweller into the mortar which is used to masonry and plaster the wall surface so that the cracking can be balanced by the moderate swell of the mortar.

根据近几年施工中的经验，分析了墙面裂纹产生的原因以及以往施工方法的得失，查阅有关资料，尝试着在砌筑及抹面砂浆中掺加膨胀剂，以砂浆自身适度膨胀抵消收缩裂纹。虽然这一方法尚不成熟，但确实值得同行们继续共同关注、探讨

The growth path of crack was increased due to the interaction of compressive and tensive stress. The effect of residual stress was kept as long as the boundary of the grains was intacted.

由于基体中压应力和拉应力的共同作用使裂纹在基体中的扩展路径增加，增加了裂纹扩展的阻力，且偏转程度显然比不考虑残余应力场时大很多。

With the aid of the experiment, crack formation and its expand pattern of ZTA ceramics under ultrasonic vibration were analyzed, its fracture criterion was established and the experiment results showed that intercrystalline fracture is the main fracture pattern of ZTA ceramics under common grinding, and transcrystalline fracture is the main fracture pattern of ZTA ceramics under TDUVAG, and the finding add to evidence showing that TDUVAG has better material removal property.

基于该方法分析具有预制裂纹的ZTA纳米复相陶瓷材料在超声振动条件下裂纹扩展方式，确立其断裂判据，通过该断裂模拟试验得出：沿晶断裂是普通磨削主要的断裂模式，而穿晶断裂是二维磨削主要的断裂模式，进一步证明二维磨削具有较好的材料去除特性。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。