Study On Impact And Blast Resistance Of Polyurea Metal Composite Structure

Polyurea elastomer has a broad application prospect in the field of engineering protection for its superior comprehensive mechanical properties.In this paper,three types of composite structure composed of SPUA-502 polyurea and 2A12O Aluminium panel were made to investigate the impact and blast resistance property of polyurea metal composite structure,with the method of experiments and numerical calculation.The main work and conclusions are as follows:(1)A cylindrical projectile launched by Hopkinson bar launching system has been used to impact the polyurea composite plates.It indicates that when coated on the impact surface,polyurea can relieve stress concentration phenomenon effectively.In terms of the resistance of local shear damage and deformation,the pure aluminium plate with the same areal density show the better performance than the sandwich structure and coating structure,and ss for the coating structure,polyurea coating on the back is better than on the front.(2)The typical working conditions of the low speed impact test were simulated with Ansys/Ls-dyna,and analyzed in terms of energy absorbtion per unit areal density,E_d.The E_d of polyurea in all composite structure are smaller than that of pure Alumnium with the same areal density,which explains why the pure aluminum plate structure has the best protective performance;Only consider the polyurea,it absorbed more energy when in the sandwich structure than in the coating structure,which could vertify the conclusion of the test.(3)The TNT weighted 60g was used to carry out the localized blast loading experiment,and we found that when covered on the back side of Alumnium,polyurea layer mainly for large areal fracture and splash,when covered on the impact side,it mainly manifests as circular broken off in the center area,and when stay between two layers of thin aluminum plate,it mainly shows the large plastic deformation with the same shape as aluminum.Besides,it reveals obvious de-bonding in all composite structure.(4)Compared with the 4mm aluminum plate,adding a thin polyurea layer into any position can reduce the deformation and damage of base board to a certain extent.However,in the condition of equivalent areal density,the bare aluminum plate has the best ability to resist deformation and damage of the explosion shock,then is the back coating structure and front coating structure,the sandwich structure performs worst.(5)With the method of Euler-Lagrange interaction,the numerical simulation analysis for explosion test was carried out.The result indicates that as the enhancement of the cohesive force between polyurea and alumnium,the deformation of aluminium in the back coating structure increases,while deformation of aluminium in the front coating structure decreases gradually,it may be for the different energy dissipation mechanism of polyurea in the different location.The result also suggested that,front coating structure deform and fracture more dramaticly along with the quality ratio of polyurea and aluminum growth.