摘要
研究液化天然气(LNG)低温储罐夹层真空丧失后,内壳应力-应变及裂纹尖端原子变化规律,揭示该状态下低温容器内壳微裂纹扩展的微观机制。应用分子动力学方法对内壳微裂纹扩展进行模拟计算,得到不同时刻微裂纹附近应力、应变、压力及原子结构的变化。结果表明:在LNG低温储罐夹层真空丧失后,其应力出现峰值后回落并趋于稳定,应力强度因子K I>K C,应变不断增加;同时,微观上可见裂纹附近出现位错累积并向前运动,使得裂纹发生扩展。
The stress-strain and crack tip atom structure of inner shell were studied after vacuum loss of LNG cryogenic stor-age tank vacuum. The micro-mechanism of inner shell crack propagation was discovered. The micro-crack propagation of in-ner shell after vacuum loss was simulated by molecular dynamics method. The changes of stress, strain, pressure and atomstructure near the micro-crack were obtained at different moment. The results show that the stress reaches the maximum valuefirst, then decreases and tends to be stable after vacuum loss of LNG storage tank. The stress strength factor KI is larger thanKC, and the strain increases continuously. At the same time, the dislocation accumulates near crack and moves forward,which makes the crack extend.
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第1期132-136,共5页
Journal of China University of Petroleum(Edition of Natural Science)
基金
辽宁省教育厅重点实验室项目(LS2010097)
关键词
低温储罐
真空丧失
裂纹扩展
分子动力学
位错
cryogenic storage tank
vacuum loss
crack propagation
molecular dynamics
dislocation
