摘要
基于氢压理论与Griffith理论,通过分析大锻件内微孔隙的来源,建立了大锻件微孔隙在氢压下的有限元分析模型。通过数值模拟,对不同形态下的微孔隙在氢压下的应力场进行了对比分析,结果表明大锻件内原始孔洞萌生白点的可能性极小,但随着孔洞变形量的增大,在垂直于孔洞压下变形主方向的平面上,白点萌生的可能性大大提高。此外,片状裂纹上最大张应力所处的位置表明,氢压下不规则裂纹有向圆形扩展的趋势,这就解释了为何在锻件截面上观察到的白点多为圆形或椭圆形。研究结果为大锻件白点萌生的力学研究奠定了理论基础。
Based on the hydrogen pressure theory and Griffith theory,the finite element analysis model of micropore under hydrogen pressure is proposed by analyzing the source of micropore in heavy forging.Through numerical simulation,the hydrogen pressure stress field of micropore with different forms is discussed.The simulation results show that the flake initiation is very unlikely to occur around the original void in heavy forging.However,on the plane perpendicular to the void deformation direction,the flake initiation possibility increases with the expanding of void deformation.In addition,the maximum tensile stress location of the sheet crack indicates the expanding trend from irregular crack to round crack,which demonstrates the phenomenon that most of the flakes observed are round or oval on the forging section.The results provide a theoretical basis for the mechanical research on flake initiation in heavy forging.
出处
《工程力学》
EI
CSCD
北大核心
2013年第4期345-349,共5页
Engineering Mechanics
基金
国家自然科学基金项目(51075352,51005197)
关键词
微孔隙
氢压模型
应力场
白点
有限元方法
micropore
hydrogen pressure model
stress field
flake
finite element method
