摘要

With the applications of polymers and their composites in aerospace industries becoming more and more common, it is of great significance to investigate their ultrahigh-speed particle erosion behaviors. Taking poly (vinylidene fluoride) (PVDF) and its composites containing polyhedral oligomeric silsesquioxanes compound (3,3,3-trifluoropropyl)(8)Si8O12 (FP-POSS) as the research objectives, this paper analyzed the failure process under the impact of a single silicon-oxygen cluster using reactive molecular dynamics simulations. Firstly, in terms of erosion surface morphologies and erosion rates, the influence of FP-POSS on the erosion resistance of PVDF matrix was analyzed. The results indicated that the erosion resistance of neat PVDF is poor, but the addition of FP-POSS can significantly enhance its erosion resistance performance and reduce its impact crater size and erosion rate. Then in order to understand these results, the movement and fracture processes of molecular chains in neat PVDF were investigated. The effect of constraints on the movement of molecular chains was analyzed, and two stages during the chain fracture process derived respectively from the cluster impact and the thermal degradation were also obtained. Finally, by calculating the gyration radii of molecular chains and the strain field distributions, the influence and the inner mechanism of FP-POSS on the erosion resistance of PVDF were further analyzed.