摘要
基于扩展有限元方法(XFEM)建立含微裂纹缺陷细观尺度下的局部区域主裂纹模型,分别研究微裂纹与主裂纹处于共线和偏置方向时微裂纹对主裂纹造成的影响.研究结果表明:微、主裂纹处于共线时,微裂纹对主裂纹裂尖应力强度因子的影响表现为距离越近作用效应越大,距离越远影响较小;而单边偏置的双微裂纹对主裂纹裂尖应力强度因子的影响随微裂纹相对主裂纹水平位置的变化呈现周期性波动,这种波动是由微裂纹对主裂纹的增强与屏蔽作用交替变化所导致;共线和偏置两种情况下,只有距离主裂纹裂尖较近的微裂纹才会对其造成较大影响,距离较远处的微裂纹对主裂纹裂尖应力强度因子影响较小.
A model of main crack in local mesoscopic-scale area with microcrack defect is established with extended finite element method(XFEM)and the influence of microcrack on main crack located collinearly with or offset vertically from the microcrack is studied.The investigation result shows that when the microcrack and the main crack are collinear,the shorter the distance between them,the greater the influence of microcrack on stress intensity factor at the tip of the main crack will be;otherwise,the result will be opposite.The influence of the unilateral offset double microcracks on the stress intensity factor at main crack tip will exhibit periodic fluctuation with the variation of the horizontal position of main crack.This fluctuation is caused by the enhancement and shielding effect of the microcracks on the main crack.Whether in the case of collinear or offset cracks,only the microcrack close to the main crack tip will have a greater effect on the main crack,otherwise,the result will be opposite.
作者
芮执元
胡序春
冯瑞成
剡昌锋
RUI Zhi-yuan;HU Xu-chun;FENG Rui-cheng;YAN Chang-feng(College of Mechano-Electronic Engineering,Lanzhou Univ.of Tech.,Lanzhou 730050,China)
出处
《兰州理工大学学报》
CAS
北大核心
2018年第2期36-41,共6页
Journal of Lanzhou University of Technology
基金
甘肃省自然科学基金(148RJZA008)
甘肃省高等学校科研项目(2014A-033)
关键词
微裂纹
扩展有限元
主裂纹
应力强度因子
缺陷
microcrack
extended finite element
main crack
stress intensity factor
defect
