摘要
通过对K判据的适用区与裂纹尖端塑性区的比较,在塑性区一定要小于K判据适用区的条件下,给出了K判据的适用边界线和判断脆性断裂的判断式;确定了K判据在结构静强度计算中塑性修正的基本原则,并在此基础上讨论得出了塑性区尺寸小于裂纹长度,裂纹扩展寿命的估算方法仍适用,塑性对裂纹扩展寿命估算影响不大,而选用不同的经验公式估算裂纹扩展寿命所出现的误差却很大的结论。
K-criterion used to boundary line and brittle fracture are presented when the size of plastic zone around crack-tip is less than that of adaptive zone of K-criterion by comparison adaptive zone of K-criterion with plastic zone around crack-tip in this paper. The basic principle of K-criterion during plastic modification in static intension calculation of structures is determined, and then the effect of plastic zone on crack propagation life-span is discussed when the plastic zone around crack-tip is less than the length of cracks. Finally numerical examples are given to illustrate the applications of the present method by comparison with other methods.
出处
《飞机设计》
2010年第1期34-37,共4页
Aircraft Design
关键词
应力强度因子
脆性断裂
塑性修正
裂纹尖端
stress intensity factor
brittle fracture
plastic modification
crack tip
