Research On Failure Mechanisms Of UHMW-PE And Aluminum Foam Composite Sandwich Panels Under Air Blast Loading

The shock waves and high-speed fragmentation produced by the explosion of anti-ship weapons make a great threat to the structure of ships in naval warfare.The lightweight aluminum foam sandwich structure has excellent shock wave resistance due to its continuous porous energy absorbing structure,but its anti-penetration capability is poor.However,the high strength ratio and high modulus ratio of the ultra-high molecular weight polyethylene(UHMW-PE)composite make it exhibit excellent anti-penetration performance.Adding a UHMW-PE composite to a lightweight foam aluminum sandwich structure can form a UHMW-PE/foam aluminum composite sandwich structure.The study of this new sandwich structure' failure mechanisms under the air blast wave and the combined effects of shock wave and fragmentation can provide important academic and application value.The main work of this paper is as follows:(1)The dynamic mechanical behavior of UHMW-PE and aluminum foam composite sandwich plates under air-blast loading was studied by conducting experiments.The deformation and failure modes of 10 composite sandwich plates were analyzed and calculated.The effects of core material,core density and core arrangement on the anti-explosion performance of composite sandwich plates were evaluated.The results show that,with equal masses,different core configurations have different effects on the anti-explosion performance of sandwich plates.Among them,sandwich panels in which the cores are aluminum foam and the density of aluminum foams increase from the upper panel to the lower panel have the better anti-explosion performance.(2)Taking the UHMW-PE and aluminum foam composite sandwich plates as study object,the simulations on dynamic response under air blast loading were implemented using software AUTODYN.The loading process of explosion shock wave and the dynamic response process of sandwich plate were studied.The influence of different parameters on the pressure of the coupled surface of the structure,the velocity of the center point of the panel and the energy dissipation were analyzed.The results show that different core configurations have little effect on the FSI pressure of the sandwich plate,but have a greater impact on velocity of the center point and energy dissipation of the panel.(3)An experimental study on the damage characteristics of UHMW-PE and aluminum foam composite sandwich plates under the combined effects of shock waves and fragmentation is implemented.The deformation and failure modes of 5 composite sandwich panels were analyzed and calculated.The effects of core material,core density and core arrangement on anti-combined loadings performance of sandwich panels were studied.Then the damage caused by the combined effects of shock waves and fragmentation loading was compared with that caused by bare blast loading.The results show that different core configurations have different effects on the anti-combined loadings performance of the sandwich plate,and the addition of the UHMW-PE composite will significantly improve the performance of the sandwich plate against combined effects of shock waves and fragmentation loading.The research work of this dissertation provides a useful reference for using UHMW-PE and aluminum foam composite sandwich plates in warship defensive structures.