Viscous energy dissipation of kinetic energy of particles comminuted by high-rate shearing in projectile penetration, with potential ramification to gas shale | |
Su YW(苏业旺); Bazant, ZP; Zhao, YX; Salviato, M; Kirane, K | |
发表期刊 | INTERNATIONAL JOURNAL OF FRACTURE |
2015-05 | |
卷号 | 193期号:1页码:77-85 |
ISSN | 0376-9429 |
摘要 | While dynamic comminution is of interest to many processes and situations, this work is focused on the projectile impact onto concrete walls, in which predictions have been hampered by the problem of the so-called 'dynamic overstress'. Recently, in analogy with turbulence, BaA3/4ant and Caner modeled the overstress as an additional viscous stress generated by apparent viscosity that accounts for the energy dissipation due to kinetic comminution of concrete into small particles at very high shear strain rate. Their viscosity estimation, however, was approximate since it did not satisfy the energy balance exactly. Here their model is extended and refined by ensuring that the drop of local kinetic energy of high shear strain rate of forming particles must be exactly equal to the energy dissipated by interface fracture of these particles. The basic hypothesis is that the interface fracture occurs instantly, as soon as the energy balance is satisfied. Like in the preceding work, this additional apparent viscosity is a power function of the rate of the deviatoric strain invariant. But here the power exponent is different, equal to , and the apparent viscosity is found to be proportional also to the time derivative of the rate of that invariant, i.e., to the second derivative of the shear strain. It is assumed that the interface fracture that comminutes the material into small particles occurs instantly, as soon as the local kinetic energy of shear strain rate in the forming particles becomes equal to the energy required to form interface fractures. The post-comminution behavior, including subsequent further comminution and clustering into bigger particle groups to release the kinetic energy that is being dissipated by inter-group friction, is discussed and modeled. The present formulation makes it possible to eliminate the artificial damping of all types, which is normally embedded in commercial finite element codes but is not predictive since it is not justified physically. With the aforementioned improvements, and after implementation into the new microplane model M7 for fracturing damage in concrete (which includes the quasi-static rate effects), the finite element predictions give superior agreement with the measured exit velocities of steel projectiles penetrating concrete walls of different thicknesses and with the measured depths of penetration into concrete blocks by projectiles of different velocities. Finally it is pointed out that the theory presented may also be used to predict proximate fragmentation and permeability enhancement of gas shale by powerful electric pulsed-arc explosions in the borehole. |
关键词 | Comminution Fragmentation High Strain Rate Impact Dynamic Fracture Fracture Mechanics Concrete Gas Shale |
学科领域 | Materials Science ; Mechanics |
DOI | 10.1007/s10704-015-0019-0 |
收录类别 | SCI ; EI |
语种 | 英语 |
WOS记录号 | WOS:000354904900006 |
项目资助者 | U.S. Army Research Office, Durham ; ADD, Korea, through a Daejeon University |
课题组名称 | LNM苏业旺 |
论文分区 | 二类/Q1 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://dspace.imech.ac.cn/handle/311007/58428 |
专题 | 非线性力学国家重点实验室 |
通讯作者 | Bazant, ZP |
推荐引用方式 GB/T 7714 | Su YW,Bazant, ZP,Zhao, YX,et al. Viscous energy dissipation of kinetic energy of particles comminuted by high-rate shearing in projectile penetration, with potential ramification to gas shale[J]. INTERNATIONAL JOURNAL OF FRACTURE,2015,193,1,:77-85. |
APA | Su YW,Bazant, ZP,Zhao, YX,Salviato, M,&Kirane, K.(2015).Viscous energy dissipation of kinetic energy of particles comminuted by high-rate shearing in projectile penetration, with potential ramification to gas shale.INTERNATIONAL JOURNAL OF FRACTURE,193(1),77-85. |
MLA | Su YW,et al."Viscous energy dissipation of kinetic energy of particles comminuted by high-rate shearing in projectile penetration, with potential ramification to gas shale".INTERNATIONAL JOURNAL OF FRACTURE 193.1(2015):77-85. |
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