Analytical models for the penetration of semi-infinite targets by rigid,deformable and erosive long rods

A theoretical study is presented herein on the pen- etration of a semi-infinite target by a spherical-headed long rod for Yp 〉 S, where Yp is the penetrator strength and S is the static target resistance. For Yp 〉 S, depending upon initial impact velocity, there exist three types of penetration, namely, penetration by a rigid long rod, penetration by a deforming non-erosive long rod and penetration by an erosive long rod. If the impact velocity of the penetrator is higher than the hydrodynamic velocity （VH）, it will penetrate the target in an erosive mode; if the impact velocity lies between the hydrodynamic velocity （VH） and the rigid body velocity （VR）, it will penetrate the target in a deformable mode; if the impact velocity is less than the rigid body velocity （VR）, it will penetrate the target in a rigid mode. The critical conditions for the transition among these three penetration modes are proposed. It is demonstrated that the present model predictions correlate well with the experimental observations in terms of depth of penetration （DOP） and the critical transition conditions.

An engineering analysis of penetration of metal ball into fibre-reinforced composite targets

An engineering analysis of computing the penetration problem of a steel ball penetrating into fibre-reinforced composite targets is presented. Assume the metal ball is a rigid body, and the composite target is a transversely isotropic elasto-plastic material. In the analysis, a spherical cavity dilatation model is incorporated in the cylindrical cavity penetration method. Simulation results based on the modified model are in good agreement with the results for 3-D Kevlar woven （3DKW） composite anti-penetration experiments. Effects of the target material parameters and impact parameters on the penetration problem are also studied.

Novel rodent models of penetrating traumatic brain injury

A penetrating traumatic brain injury（pTBI）occurs when an object impacts the head with sufficient energy to penetrate skin,cranial bone and meninges to inflict injury directly to the brain parenchyma.This type of injury is particularly common in areas plagued by armed conflicts or gun-related violence.

Simulations of vertical jet penetration using a filtered two-fluid model in a gas-solid fluidized bed

The influence of a vertical jet located at the distributor in a cylindrical fluidized bed on the flow behavior of gas and particles was predicted using a filtered two-fluid model proposed by Sundaresan and coworkers. The distributions of volume fraction and the velocity of particles along the lateral direction were investigated for different jet velocities by analyzing the simulated results. The vertical jet penetration lengths at the different gas jet velocities have been obtained and compared with predictions derived from empirical correlations; the predicted air jet penetration length is discussed. Agreement between the numerical simulations and experimental results has been achieved.

Design and analysis of firewall-penetrated scheme based on trusted host

On the basis of various firewall-penetrated technologies, a novel firewall-penetrated technology based on trusted host, which can realize the communication between penetrating host and protected host, is proposed in this paper. Meanwhile, the firewall-penetrated evaluating model and its formalized statement is also proposed by quantizing penetrated level, penetrated quality, and penetrated hiding. Finally, the fuewall-penetrated technology based on trusted host is analyzed under the fuewall-penetrated evaluating model, and the experimental results show that this technology has obvious penetrating effect and high penetrating quality.