摘要
为研究双孔爆炸裂纹扩展规律,以有机玻璃(PMMA)为介质,利用有限差分软件Autodyn分别对不同孔距(L=7 cm,9 cm,11 cm,13 cm和15 cm)下无导向孔、普通导向孔(空孔)与切槽导向孔的双孔爆炸裂纹扩展进行了数值模拟。采用线性状态方程和JH-2(Johnson-Holmquist)本构模型对体量与偏量进行描述,并引入拉伸断裂软化模型进一步刻画爆炸裂纹效果。为验证PMMA材料模型与物性参数,首先对单孔裂纹扩展进行了模拟,结果再现了裂纹粉碎区和裂隙区,径向裂纹与环向裂纹,裂纹起裂、扩展、分叉与止裂以及二次扩展等行为,成功验证了材料模型与物性参数的适用性。双孔爆炸裂纹扩展模拟结果表明:无导向孔情况下,孔距L是裂纹贯穿最重要影响因素,贯穿方式属于拉伸裂纹相互主动贯穿;普通导向孔和切槽导向孔的导向作用体现在应力集中与缩短裂纹贯穿距离上;孔距L一定时,空孔尺寸效应在一定范围内有利于裂纹贯穿。从裂纹定向扩展效果而言,切槽导向孔的导向作用最强,普通导向孔次之,无导向孔最差。裂纹贯穿机制体现在三方面,即贯穿位置、贯穿裂纹类型与贯穿方式。
Here,to study crack propagation law of double-hole explosion,taking the plexiglass material polymethyl methacrylate(PMMA)as the medium,crack propagation of double-hole explosion with no guide hole,ordinary guide hole(empty hole)and grooved guide hole under different hole spacing L of 7,9,11,13 and 15 cm was numerically simulated by using the finite difference software AUTODYN.The linear state equation and Johnson-Holmquist(JH-2)constitutive model were used to describe the volume and bias,and the tensile fracture softening model was introduced to further describe explosion crack effect.In order to verify PMMA material model and physical parameters,single-hole crack propagation was simulated firstly,and the results reproduced behaviors of crack crushing zone and crack zone,radial crack and circumferential crack,crack initiation,propagation,bifurcation,crack arrest and secondary propagation.The applicability of the material model and physical parameters was successfully verified.The simulation results of dual-hole explosion crack propagation showed that in the case of no guide hole,the hole spacing L is the most important influencing factor of crack penetration,and the penetration mode belongs to tensile cracks active inter-penetration;guiding action of ordinary guide hole or grooved guide hole is reflected in stress concentration and shortening crack penetration distance;when the hole spacing L is constant,the empty hole size effect is conducive to crack penetration in a certain range;for crack directional propagation effect,the guiding action of grooved guide hole is the strongest,followed by ordinary guide hole,and no guide hole is the worst;the crack penetration mechanism is reflected in 3 aspects of penetration position,penetration crack type and penetration mode.
作者
蒲传金
杨鑫
肖定军
程建龙
周磊
陈旭
PU Chuanjin;YANG Xin;XIAO Dingjun;CHENG Jianlong;ZHOU Lei;CHEN Xu(School of Environment and Resource,Southwest University of Science and Technology,Mianyang 621000,China;Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province,Mianyang 621000,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;Key Laboratory of Deep Underground Science and Engineering(Ministry of Education),College of Architecture and Environment,Sichuan University,Chengdu 610065,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第15期300-311,共12页
Journal of Vibration and Shock
基金
四川省教育厅自然科学基金重点项目(17zd1122)
四川省科技计划(2021YJ0394,2021YJ0511,2021YJ0525)
西南科技大学自然科学基金(19zx7168)
地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2021K009)。
关键词
裂纹扩展
数值模拟
贯穿机制
空孔尺寸效应
切槽导向孔
crack propagation
numerical simulation
penetration mechanism
size effect of empty hole
grooved guide hole
