摘要
针对现有基于拉/压、球/偏应变能分解的2种复合型相场模型间差异性及其适用范围缺乏比较研究等问题,采用交错算法,依托ABAQUS平台自编相场本构子程序UMAT和相场变量演化子程序HETVAL,建立2种复合型相场模型数值求解方法,模拟脆性岩石双裂纹渐进式扩展贯通过程并对比分析。通过开展不同中心平行间距下含双平行裂纹的红砂岩试件单轴压缩试验,比较验证2种复合型相场模型的有效性并阐明其异同性及适用范围。研究结果表明:随着中心间距的增加,双平行裂纹的起裂点位置、扩展方向(I型翼裂纹起裂,扩展方向近似垂直于原裂纹面)和二次萌生裂纹(Ⅱ型裂纹)扩展方向几乎不变,但二次萌生裂纹的位置从2个内尖端变为2个外尖端,且岩桥贯通轨迹从2组裂纹尖端间扩展贯通变成1组裂纹内尖端扩展贯通;2种复合型相场模型均能有效地模拟出Ⅰ型、Ⅱ型裂纹扩展,但基于球/偏应变能分解的复合型相场模型模拟的二次萌生裂纹扩展(Ⅱ型反翼裂纹,扩展方向与翼裂纹方向相反)和岩桥贯通轨迹(裂纹尖端翼裂纹直接相向扩展贯通)与试验结果更为吻合,更适合于复杂加载条件下的脆性岩石多裂纹扩展行为模拟。
Aiming at the low comparative research on the difference and application scope of the two mixedmode phase field models(which based on the decomposition of the total elastic strain energy into tensile/compressive and volumetric/deviatoric elastic strain energy, respectively), a numeric solution method of the two mixed-mode PFMs was established by the staggered solution method with self-programmed subroutines UMAT and HETVAL of ABAQUS to simulate the whole propagation process of the double-cracked rock specimens with different center distance under uni-axial tension. Research results show that with the increase of the center distance, the initiation positions, the propagation direction of the double parallel cracks(Mode I wing-crack, the direction of propagation is approximately perpendicular to the original crack surface) and the initiation direction of the secondary cracks(Mode Ⅱ) are almost unchanged, while the initiation positions of the secondary cracks are changed from the two inner-tips to the two outer-tips, and the coalescence trajectories of rock bridge are also changed from two groups of crack-coalescence to one group of crack-coalescence. The two mixed-mode PFMs can effectively simulate Mode I and Mode II crack propagation. Comparatively, the PFM based on the decomposition of the total elastic strain energy into volumetric/deviatoric elastic strain energy has closer simulation results of the secondary cracks(anti-wing crack, the direction of propagation is opposite to that of the wing crack) and the coalescence trajectories of rock bridge(the wing cracks at the crack tip extend directly opposite each other) to the test results and better applicability in simulating the multi-cracks propagation of brittle rock under complex loading conditions.
作者
赵晨臣
饶秋华
易威
罗三
ZHAO Chenchen;RAO Qiuhua;YI Wei;LUO San(School of Civil Engineering,Central South University,Changsha 410075,China;Guizhou Qianhang Traffic Engineering Co.,Ltd.,Guizhou Road&Bridge Group Co.,Ltd.,Guiyang 550018,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第2期565-575,共11页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51874351,52078495)。
关键词
复合型相场模型
应变能分解
交错法
脆性岩石
裂纹扩展
mixed-mode phase field model
strain energy decomposition
staggered method
brittle rock
crack propagation
作者简介
通信作者:饶秋华(1965−),女,江西丰城人,教授,博士,从事工程断裂研究,E−mail:raoqh@csu.edu.cn。
