Effect of polyurea coating with different mechanical properties on blast resistance of aluminum alloy circular tube structures: Experiments vs numerical simulations

Abstract

Polyurea has attracted extensive attention in the field of anti-blast protection over the past few years. Two types of polyurea were prepared and their quasi-static and dynamic mechanical properties were examined to investigate the effect of polyurea coating with different mechanical properties on the blast resistance of the metal circular tube structure. A set of automatic spray equipment was designed and manufactured to spray polyurea efficiently on the circular tube structure. On that basis, the anti-blast test was performed using the two types of polyurea coated on the surface of 6063-T5 aluminum alloy circular tubes with different thicknesses. The macro and micro damage characteristics of polyurea coated aluminum tubes were obtained using the field tests, the metallographic microscope and the scanning electron microscope (SEM) technology. Numerical simulation models were built to elucidate the dynamic response process. The results suggest that polyurea is capable of significantly enhancing the blast resistance performance of the aluminum alloy circular tube. In contrast, polyurea with better energy absorption effect under high dynamic load may not exhibit higher protective efficiency. Whether the polyurea and the aluminum tube can always maintain the adhesion relationship and deformation together under the action of blast has been confirmed as a vital factor. Lastly, the energy absorption mechanism and influence mechanism of different kinds of polyurea were revealed using the Fourier Transform Infra-Red (FTIR) technology in accordance with the stress wave theory.