Fluid Based Protective Structures

This paper describes rheological tests, drop tests and bulletproof tests of materials which are planned to be used as elements of bulletproof vests as well as in high impact protective equipment. Rheological tests of a homogenous composition of methyl-, phenyl-, borosiloxane polymers (KM material) performed for variable values of stress and strain at a fixed frequency of 1 Hz showed that the loss modulus exceeds the storage modulus throughout the whole tested range of shear stress so that the energy is more dissipated than stored. In the drop tests, same-mass samples of three materials, i.e. the KM material, the shear thickening fluid STF1 and the commercial shear thickening polymer ZB were tested. For a given impact energy (Ei = 35 J) and impact velocity (Vi = 1.9 m/s), the ZB material shows the best protective capability. In the ballistic tests, the sample with the KM material was tested with the use of .44 Magnum SJHP (semi-jacketed hollow-point) bullet following NIJ Standard-0101.04 for IIIA bulletproof class. The results were compared to the bulletproof tests of the ZB material from previous works. Better protective capability was achieved in the case of a commercial material. However, the tested KM material also exhibited the energy dissipation capability. Further work is needed to investigate the effectiveness of the KM material in a different type of casing.