裂纹

In order to calculate the crack expansion life in the action of variable amplitude load for the metal bar with V-shaped notch, the formula of bar fracture frequency was obtained theoretically by setting a size of bar fracture region applied in the engineering. Based on it, the mathematic expression of crack expansion life of bar V-shapednotch tip in the action of variable amplitude load was built.

针对金属棒料在变幅载荷作用下需要较精确地获取其V形槽尖端裂纹扩展寿命的问题，通过给定一个工程上能接受的瞬断区尺寸，获得了棒料断裂频率的计算公式，在此基础上，建立了变幅载荷作用下棒料V形槽尖端裂纹扩展寿命的数学表达式。

Based on the complex potential method about the plane theory of the elasticity of an anisotropic body,stress distributions in the plate with multiple cracks are obtained by using the conformal mapping and the Faber series expansion.

采用各向异性体平面弹性理论中的复势方法，应用保角映射技术和F aber级数展开，导出在任意载荷作用下多裂纹板应力场的级数解，引入当量屈服应力修正裂尖塑性区，并利用Sw ift韧带屈服准则建立含共线分布多裂纹结构的剩余强度分析模型，计算结果与试验结果吻合较好。

The forms of fatigue cracks in bore of gun barrel are considered as edge cracks and semi-elliptical cracks. The stress intensity factors of gun barrel are calculated using a weight function method under the autofrettaged residual stress, thermal stress and assemblage stress.

3武器身管内表面的疲劳裂纹考虑为边裂纹和半椭圆型表面裂纹两种形式，用权函数方法研究了身管在自紧残余应力、温度应力和装配应力作用下的应力强度因子。

Commercial experiments were implemented with M- EMS and F- EMS at a billet caster in Iron and Steel Group Company of Qingdao for high carbon steel casting.

对结晶器电磁搅拌和末端电磁搅拌改善优质碳素钢连铸小方坯质量的工业性对比试验进行总结，结果表明，在现有的工艺条件下，选择合适的搅拌参数可较好地改善连铸坯的中心裂纹、中间裂纹、中心疏松、缩孔、角部裂纹和中心碳偏析。

The results show that: when the stress triaxiality is low, the penny-shaped crack can lead to damage anistropy of a ductile material; and the variance of Lodes parameter will lead to the variance of the expanding rate and deformed shape of penny-shaped crack and sphere-shaped void.

进而对材料中同时含有币形微裂纹和球形微孔洞的情形作了数值模拟分析。计算结果表明：币形微裂纹的存在将导致低应力三轴度下韧性材料破坏的细观损伤呈现明显的各向异性；而Lode参数对微裂纹和微孔洞的长大和变形状态具有较大的影响。

In order to reduce the tendency of hot crack in thin plate welding, a new process named Welding with Trailing Peening is used to prevent the weldments from welding hot crack by experiments and measurements from the view of mechanics.

针对焊接时薄板构件产生焊接热裂纹倾向大的缺点，从力学角度出发，采用随焊锤击的焊接新工艺，并利用试验和测试技术，来达到防止薄板焊接热裂纹的目的，开辟一条解决焊接热裂纹的新途径。

In order to reduce the tendency of hot crack in thin plate welding, a new process named Welding with Trailing Peening is used to prevent the weldments from welding hot crack by experiments and measurements from the view of mechanics. And the fundamental principle of WWTP is discussed.

针对焊接时薄板构件产生焊接热裂纹倾向大的缺点，从力学角度出发，采用随焊锤击的焊接新工艺，并利用试验和测试技术，来达到防止薄板焊接热裂纹的目的，开辟一条解决焊接热裂纹的新途径。

And the strengthening mechanism can be described as follows: WC cemented carbides have interlaced short-clubbed grain, and in the bend strength test, the microcrack generates at WC/WC grain boundary, and may be blocked by interlaced fine-clubbed grains during extending, which induce the intergranular pulling-out. Due to the pulling-out mechanism, fracture-extend energy is greatly expended, thus bend strength is increased. The wear mechanism is groove wear and spalling of WC grains.

热机械合金化合成的WC-Co硬质合金比传统方法制备的同类WC合金具有更高的强度，其机理是：热机械合金化合成的WC合金具有交替排列的短棒状组织，在三点弯曲试验中，微裂纹萌生于WC/WC晶界位置，受到交错排列的短棒状晶粒的阻碍，裂纹扩展以短棒状晶粒的拔出方式进行，极大地消耗了裂纹扩展的能量，从而提高了弯曲强度；合成试样的摩擦磨损过程以犁沟磨损和WC颗粒的剥落为主要特征。

This paper discusses the causes to form subsurface transversal crack in silicon aluminum killed steel slab with straight mold type caster.

论述了直弧型板坯连铸机生产硅铝镇静钢时产生皮下横裂纹的机理及原因，并找出了产生皮下横裂纹的主要原因，w高及铌增加了铸坯的裂纹敏感性。

Graph 1 fore-and-aft hot crack pursues if the hot crack form of model of 2 local hot crack pursues show 3 times.

图1纵向热裂纹图2局部热裂纹典型的热裂纹形式如图3所示。

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。