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The protective performance of foam aluminum-Al composite structures with different densities and thicknesses are investigated with conventional and improved split Hopkinson pressure bars ( SHPB). The experimental results demonstrate that, when foam Aluminum is used as interlayer, the primary stress wave is divided into several stress waves. The time of stress wave arriving at a back plate is postponed, and the wave intensity decreases. The impact of stress wave decreases more clearly with the increase in thickness of interlayer. When foam aluminum-Al composite structure is used as faceplate, the pulse width broadens, the rising edge is improved, and the wave intensity reduces. At the same time, the foam aluminum-Al composite structures can absorb a large part of impact energy, which can be served as stress wave protective material. With the increase in thickness and relative density of the foam aluminum, the wave shaping effect is more significant. The wave intensity reduces, the rising slop becomes flat, however the stress wave pulse changes little. The influence of A1 plate thickness on composite structure can be ignored. [ABSTRACT FROM AUTHOR]

The effects of relative density of magnesium alloy foams on their dynamic mechanical properties and energy absorption characteristics are investigated. Split Hopkinson pressure bar (SHPB) is used to evaluate the dynamic compressive behaviors of magnesium alloy foams with different densities. The experimental results show that, with the increase in relative density, the yield stress and platform stress increase significantly while the densification strain decreases. Based on the experimental results, the fitting equations of yield stress and relative density are obtained. The energy absorption properties of metal foams are characterized by energy absorption per unit volume, energy absorption efficiency and ideal energy absorption efficiency. The higher the relative density of magnesium alloy foams is within a certain range, the higher the energy absorption capacity per unit volume is. The energy absorption efficiency decreases slightly, but it is steady at about 0.3, while the stress corresponding to the highest absorption efficiency increases. Magnesium foam is a kind of material with better protective performance, with the ideal energy absorbing efficiency reaching 0. 9. [ABSTRACT FROM AUTHOR]

In order to study the range profiles of laser fuze installed on intelligent mine, the dynamics, kinematics and analytic geometry are applied in scanning movement modeling of intelligent mine submunition. The mathematics models of ground, barriers, armored targets, and rendezvous of scanning line and target are established by using an analytic geometry method. At the same time, the computer numerical simulation of range profiles of laser fuze scanning the stationary and moving armored targets are carried out under the influence of different barriers. The results show that laser fuze could detect target repetitiously, the frequency and time of detecting target depend on the relative position of the mine submunition and target, and the range profiles of laser fuze has uniqueness for the target with unique figuration. The simulation model can provide references for overall design of intelligent mine, design of laser fuze and research on target recognition algorithm. [ABSTRACT FROM AUTHOR]