检索结果-南通市图书馆

Deformation,fragmentation and acceleration of a controlled fragmentation charge casing

Defence Technology（防务技术） 2019年第5期15卷 786-795页

作者： Andreas Helte Olof Andersson patrik lundberg FOI Defence and SecuritySystems and Technology

Two different finite element software,LS-DYNA and Impetus,have been evaluated to test their ability to predict the deformation,fragmentation and acceleration of a controlled fragmentation charge *** general-purpose program LS-DYNA was used with a multi-material ALE formulation and a masspreserving erosion criterion coupled to a Johnson-Cook fracture *** the Impetus simulations,a third order Lagrangian element formulation was used for the casing and a node-splitting element erosion treatment coupled to a Cockcroft-Latham failure criterion was used to describe casing *** high-explosive gases were described by a discrete particle *** order to acquire data to validate our computational tools and constitutive models,a series of experiments have been performed using a laboratory charge with an internal grooved *** the test series,the charge geometry was fixed except that the groove depth were varied from very shallow to very deep resulting in different deformation patterns,fracture modes and terminal *** diagnostic tools captured the different stages of the expansion and fragmentation of the casing.A high-speed framing camera depicted the deformation pattern before fragmentation and was used to determine the moment when the casing *** different complementary techniques were used to follow the acceleration of the fragments;a Photon Doppler velocimetry to determine the initial acceleration of the casing,double exposed radiographs to estimate the fragment velocity after break-up and a high-speed video to determine the terminal velocity of the fragment after leaving the *** addition,the fragments were soft recovered in a set of sawdust pit tests and their final shape and weight were measured.A SEM was used to characterise the fracture surfaces and to determine the modus of fracture(tensile or shear failure).Comparisons to experiments show that both software can predict the change in deformation behaviour

关键词： Controlled fragmentation Fracture mechanics LS-DYNA Impetus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of confining prestress on the transition from interface defeat topenetration in ceramic targets

引用

Defence Technology（防务技术） 2016年第3期12卷 263-271页

作者： patrik lundberg RenéRENSTROM Olof ANDERSSON FOI Swedish Defence Research AgencySE-164 90 StockholmSweden

Replica scaled impact experiments with unconfined ceramic targets have shown that the transition velocity,i.e.,the impact velocity at which interface defeat ceases and ceramic penetration occurs,decreased as the length scale increased.A possible explanation of how this scale effect is related to the formation of a cone crack in the ceramic has been presented by the authors in an earlier ***,the influence of confinement and prestress on cone cracking and transition velocity is *** hypothesis is that prestress will suppress the formation and growth of the cone crack by lowering the driving stress.A set of impact experiments has been performed in which the transition velocity for four different levels of prestress has been *** transition velocities as a function of the level of confining prestress is compared to an analytical model for the influence of prestress on the formation and extension of the cone crack in the ceramic *** experiments and model indicate that prestress has a strong influence on the transition from interface defeat to penetration,although the model underestimates the influence of prestress.

关键词： Impact Ceramic Armour Interface defeat Dwell Confinement Prestress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：