Deformation of polyurea-coated steel plates under localised blast loading

Abstract

Experimental and numerical studies were conducted to investigate the effect of polyurea coatings on the blast resistance of mild steel plates. Square steel plates with and without polyurea coatings applied to the back surface were subjected to localised blast loading, both experimentally and numerically using ANSYS® AUTODYN®. Two coating thicknesses were considered which were chosen such that each of the plates had the same areal density of 4.7 g/cm2 over the test area. The residual deformations of the plates were measured after each event and found to increase with coating thickness. The transient deformations of the plates were captured using high speed video. The video revealed that the polyurea coatings de-bonded over a circular area, resulting in a hyperelastic extension of the polyurea and a maximum transient deformation approximately twice that of the bare steel plates. Close agreement was found between the experimental and numerical results for the residual deformations; however, the peak transient deformations were under-predicted in the numerical models. This lead to the development of new Mooney–Rivlin material model constants for the polyurea which gave improved results. It was found that a numerical bond strength of 80 MPa between the polyurea and the steel gave the closest match with the experimental results. Further numerical modelling which varied coating thickness and location found no coating solutions which deformed less than a bare steel plate of equivalent areal density.