摘要
在扩展有限元的框架下,引入一个内聚的裂尖加强函数,相比传统的裂尖加强函数而言,该内聚加强函数具有相同精度但自由度很少的优势。采用改进的扩展有限元方法对裂尖附近小孔的不同布置方案下裂纹的扩展过程进行了追踪模拟,基于相互作用积分的方法计算了裂尖移动过程中的应力强度因子序列,并提出一个裂尖汇合到小孔后的应力强度因子计算策略。通过扩展路径和应力强度因子的对比分析,发现小孔对裂纹的扩展具有一定的诱导性,且裂纹如果汇合到小孔,则应力强度因子会突然变小,形成止裂的效果,但如果不汇合,则止裂效果不明显,甚至加剧扩展。
Under the extended finite element framework,a cohesive tip enrichment function was introduced which was of merits of same accuracy but less degree of freedom than that of traditional XFEM.For different layout schemes of micro holes near the crack tip,the crack extension processes had been tracked by the modified extended finite element method.And the stress intensity factor series when crack tip moving were calculated based on interaction integral method,and a calculated strategy of stress intensity was proposed when crack tip joined up to micro hole.Through the comparative analysis of their extension paths and stress intensity factors,we found that the micro hole was of certain inductive effect to crack extension,that the stress intensity factor decreases suddenly,forming arrest effect,when the crack joined up to micro hole,and while the crack arrest was not obvious or even intensifies extension when crack does not joined up to micro hole.
出处
《能源与环保》
2017年第11期228-233,237,共7页
CHINA ENERGY AND ENVIRONMENTAL PROTECTION
关键词
扩展有限元
小孔
止裂
应力强度因子
互作用积分
XFEM
micro hole
crack arrest
stress intensity factor
interaction integral method
