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Ultra-high-molecular-weight polyethylene (UHMWPE) fiber laminate is currently widely used in ballistic protection for its exceptional physical and mechanical properties. However, the dynamic compressive mechanism of UHMWPE laminate remains poorly understood. Therefore, the stress–strain relationship, the influence of different thickness, area, and shape, and the maximum stress and fracture stress are studied in both out-of-plane and in-plane directions under quasi-static and dynamic loading using a universal test machine, Split Hopkinson pressure bar (SHPB), and high-speed camera. Furthermore, numerical models with cohesive elements are developed. The results indicate a dependency on strain rate and loading direction. Firstly, the stress–strain curve of dynamic testing can be divided into different zones according to different loading directions and strain rates. Secondly, with the increase of the strain rate in the dynamic testing, the maximum stress and fracture stress increase as well; relatively speaking, the fracture stress in the out-of-plane direction is greater than the fracture stress in the in-plane direction. Thirdly, both experiment and simulation indicate that the thickness does not influence the modulus clearly the in out-of-plane direction but influences the modulus in the in-plane direction. Fourthly, the fracture stress of dynamic testing is higher than the fracture stress of quasi-static testing in both directions. Finally, the numerical results show good agreement with the experiment in terms of the maximum stress and failure form.

In the last few decades, various researches focus on the transient pressure in the behind armor blunt trauma. This paper presented a investigation on the transient pressure in the ballistic gelatin behind a soft body armor subjected to the impacting from three ammunitions. Experimental results show that three peaks appear on the pressure-time curves without taking into account the ammunition type and the impact velocity. Furthermore, numerical models of the test were created to compare modelling results to the pressure from the pressure gauges buried in the gelatin block. The main features on the pressure-time cure were discussed to analyze the wave formation and propagation. With the verified model, the effect of the boundary was also investigated to explain the wave reflection which appeared after two peaks.

The superimposition of simulant penetration profiles produced from ballistic gelatin simulant has been used to predict wound tracts in damaged tissues. The authors recognise that determining clinical effectiveness based on the AIS scores alone without verification of outcome by review of clinical hospital records means that this technique should be seen more as a manner of comparing the effectiveness of bullets than an injury prediction model.

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