?study On The Penetration Resistance Of Polyurethane Elastomer Composite Plate

Polyurethane steel composite panels are widely used in fields such as shipbuilding and construction due to their excellent specific strength and stiffness.The evaluation of penetration impact protection for polyurethane steel composite plates has become a hot topic.In this paper,three kinds of hardness polyurethane elastomers and corresponding composite plates were prepared with MDI8617 and castor oil as raw materialsConduct quasi-static and dynamic compression experiments on polyurethane elastomers with three different hardness levels,and the results show that the stress level of polyurethane elastomers during quasi-static compression increases with the increase of polyurethane hardness and strain rate;In the dynamic compression experiment,when the strain rate reaches1900/s,all three types of hardness polyurethane undergo failure.The higher the hardness,the more obvious the strain rate effect,and the higher the degree of brittle failure exhibited during failure.Penetration experiments were conducted on polyurethane steel composite plates and polyurethane carbon fiber steel composite plates with three different hardness levels,and scanning electron microscopy analysis was conducted.The results showed that the main failure modes of the composite plates were delamination between the polyurethane layer and the panel,plastic deformation and cracking of the panel,and damage to the polyurethane layer;The increase in hardness of the polyurethane layer results in an increase in the ballistic limit velocity of the composite board;The energy absorption rate of the composite plate also decreases with the increase of the initial velocity of the projectile.The larger the initial velocity,the smaller the deformation of the panel,and the energy absorption rate also decreases;After adding a carbon fiber layer,the anti penetration ability of the composite plate is improved,and the higher the hardness of the polyurethane,the more the ballistic limit speed is increased after adding a carbon fiber layer;The higher the hardness of polyurethane,the more severe the penetration fracture tearing,and the more obvious the delamination phenomenon.DMA testing was conducted on polyurethane samples,and penetration experiments were conducted on polyurethane steel composite plates with three different hardness levels at ambient temperatures below the glass transition temperature of polyurethane elastomers.The results showed that the ballistic limit velocities of the three hardness levels increased by60.4m/s,60.8m/s,and 37.7m/s,respectively;Compared with room temperature conditions,the ballistic limit velocity under low temperature conditions has increased by 42.9%,40.7%,and 24.1%,respectively;Through cross-sectional analysis of the specimen after penetration,it was found that the brittle failure characteristics of high hardness polyurethane are obvious,while low hardness polyurethane still retains some elastic characteristics.The process of projectile penetration into composite plates was studied using finite element numerical simulation.It was found that when high-speed projectiles act on the composite plate,the attack surface first fails,and at the same time,the panel undergoes debonding under the influence of stress waves.The failure of the back plate precedes that of the polyurethane elastomer core layer.The polyurethane elastomer is finally penetrated.At the same time,numerical simulations were conducted on the penetration of polyurethane composite plates by pointed and flat projectiles,and compared with experimental results.It was found that the penetration ability of the three types of projectiles was the strongest,followed by spherical and flat projectiles.During the penetration process,the deformation of the panel was more uniform,while the damage to the polyurethane core layer was relatively small.The contact area between the flat nose projectile body and the target plate is the largest,and the penetration ability is the smallest,which can cause maximum damage.