Design of Multi-layered Protection Against Guided Mortar Threats Yhrough Numerical Modeling

The trade—off between protection and weight is a constant consideration when designing a portable protective solution.Greater mobility is a desirable attribute and protection must therefore adapt,prompting a demand for lightweight,simple to construct,low-cost and effective ballistic protection systems.High strength and ductility,wave spreading capability and good energy absorption are key properties for ballistic protection.Four materials,polycarbonate,Kevlar?-epoxy,polyurethane foam,and aluminium alloy,possess these properties and were selected for analysis by numerical simulation.Multilayered configurations were proven to be an optimal solution,by exploiting the advantages of each material without having large penalties of mass and cost.Numerical modelling using ANSYS AUTODYN?is used to simulate monolithic and multi-layered target configurations,to obtain the penetration mitigation performance.The results are analysed to select configurations based on different requirements,such as lowest cost,lowest mass,best performance,and optimal configuration which balanced the three key parameters mentioned.The optimal configuration of Aluminium,Kevlar-Epoxy,Polyurethane,and Polycarbonate has layers with thickness of 7,3,38,2 mm respectively with a total mass of 7.97 kg,total cost of$39.86 and penetration of 29.34%(14.67 mm).Polynomial relationships between performance and mass/cost are also determined.

Development of tuneable effects warheads

The tuneable effects concept is aimed at achieving selectable blast and fragmentation output,to enable one charge to be used in different scenarios requiring different levels of blast and fragmentation lethality.It is a concept Qineti Q has been developing for an energetic fill consisting of three principal components arranged in co-axial layers,two explosive layers separated by a mitigating but reactive layer.The concept was originally designed to operate in two modes,a low output mode which only detonates the central core of high explosive and a high output mode which detonated both the central core and outer layer of the explosive.Two charge case designs where manufactured and tested;one of these designs showed a reduction in blast and fragment velocities of^33%and^20%,respectively,in the low output mode.

Effects of underground explosions on soil and structures

Much effort has been dedicated to the study of underground explosions because they pose a major threat to people and structures below or above the ground.In this regard,it is especially important to model the propagation of blast waves in soil and their effects on structures.The main phenomena caused by underground explosive detonation that must be addressed are crater or camouflet formation,shock wave and elastic–plastic wave propagation in soil,and soil-structure interaction.These phenomena can be numerically simulated using hydrocodes,but much care must be taken to obtain reliable results.The objective of this study is to analyze the ability of a hydrocode and simple soil models that do not require much calibration to approximately reproduce experimental and empirical results related to different buried blast events and to provide general guidelines for the simulation of this type of phenomena.In this regard,crater formation,soil ejecta,blast wave propagation in soil,and their effects on structures below and above the ground are numerically simulated using different soil models and parameters;the results are analyzed.The properties of soil have a significant effect on structures,the ejecta,and the propagation of shock waves in soil.Thus,the model of the soil to study these phenomena must be carefully selected.However their effect on the diameter of a crater is insignificant.