论文部分内容阅读
实际金属材料及其合金中,总是不可避免地有裂纹。裂纹高速传播的可能性决定构件所处的力学状态以及材料本身的性质。一般高强材料构件处于平面应变力学状态中,裂纹较易高速传播,使其构件发生低应力“脆性”破坏。这种“脆断”,断裂后,材质不产生明显的宏观屈服现象。裂纹是在材质所处的弹性状态中穿透构件,因此采用弹性力学的理论来描述这种现象是很自然的。根据弹性力学理论以及裂纹尖端这一特殊状态,提出用“应力强度因子”观点来衡量高强材料抗裂能力是最有实际意义的。K_(IC)是描述高强材料在平面应变力学状态中材质的抗裂能力;K_C是描述中低强材质在平面应力力学状态中材质的抗裂能力。
In actual metal materials and their alloys, cracks are always inevitable. The possibility of crack propagation at high speeds determines the mechanics of the component and the nature of the material itself. General high-strength material components in the plane strain state of mechanics, the cracks easier to high-speed transmission, so that the components of low stress “brittle” damage. This “brittle fracture”, fracture, the material does not produce significant macro yield phenomenon. Cracking is the penetration of components in the elastic state in which the material is located, so it is natural to describe this phenomenon using the theory of elasticity. According to the theory of elastic mechanics and the special state of crack tip, it is the most practical significance to use the “stress intensity factor” view to measure the crack resistance of high strength materials. K_ (IC) is the material that describes the crack resistance of high-strength materials in the plane strain state. K_C is the material’s crack resistance in the plane stress mechanics state.