Dynamic Response Of Metal Sandwich Panel Subjected To Foamed Aluminum Projectile Impact Loading

Metal sandwich panels are widely used in various structural parts of warships because of their excellent energy absorption characteristics and lightweight.With the continuous development of metal sandwich structure,it has played an important role in resisting explosive impact load and improving the protection ability of warship and has become the research focus of domestic and foreign scholars.At present,in the experimental study of the dynamic response of metal sandwich structure,the academic circles mainly exert the impact loading by means of explosion,there are some problems,such as poor safety,impulse cannot be accurately controlled and so on.As a result,it is difficult to carry out the experimental research and the experimental results are not satisfied.In order to accurately load impulse to the sandwich panel under conventional laboratory conditions,the dynamic response of metal sandwich panel under strong impact load is studied by means of the impulse produced by the impact of high-speed aluminum foam projectile on metal sandwich panel.The main research work and conclusions are as follows:(1)An experimental study was applied to investigate the impact of high-speed aluminum foam projectile on metal sandwich panel.The aluminum foam projectile is accelerated by Hopkinson pressure bar device(SHPB),and the impulse is controlled by adjusting the length and the impacting speed of the projectile.According to the test results,the deformation failure modes of the front,rear faces and intermediate core of the metal sandwich panel under the impact of high-speed aluminum foam projectile are analyzed.The effects of different thicknesses of the front and rear faces,different thicknesses of the core layer and different impact velocities of projectile on the dynamic response of metal sandwich panel are studied.(2)The finite element software Abaqus is used to simulate the impact process of aluminum foam projectile on metal sandwich panel,and the dynamic response mechanism of metal sandwich panel subjected to high-speed aluminum foam projectile impact is revealed.The effects of different load parameters and different structural parameters of the metal sandwich panel on the impact resistance of sandwich panel are further studied by numerical modelling.It is found that there is a linear relationship between the length and the impacting speed of projectile and the maximum contact force.In addition,a new structure design is carried out for the intermediate core shear failure of the metal sandwich panel,which improves the impact resistance of the metal sandwich panel and the shear resistance of the inter core layer.(3)Based on the ideal rigid-plastic model of metal sandwich panel,the dynamic response of metal sandwich panel with aluminum foam in the middle layer under the impact of high-speed aluminum foam projectile is discussed by means of square yield rule.According to the different response time,it is divided into three moving phases of plastic hinge line,which are as follows: the action stage of rectangular pulse loading on the metal sandwich panel,the movement of the plastic hinge to the midpoint of the sandwich panel,and the response stage of the whole structure of the metal sandwich panel.The expression of the deflection of the rear face of the metal sandwich panel is given.Finally,the theoretical value of the deflection of the rear face of the sandwich panel is compared with the experimental value,and the correctness of the theoretical derivation is verified,and the error analysis is carried out.