Assessment of high-velocity impact effects on carbon fiber reinforced polymer sandwich panel with M-shaped core reinforced by nano-SiO_2: Experimental and numerical study

摘要

This paper describes the high-velocity impact behavior of composite sandwich panels with different amounts of nano-SiO_2. The sandwich panels were manufactured by carbon/fiber epoxy composite face sheets and an M-shaped core using the vacuum-assisted resin transfer molding method. To enhance the mechanical strength of the matrix, especially impact resistance, the nanoparticles were added to the resin epoxy matrix as filler with the ratios of 1%, 2%, and 3% of the composite's total weight. A scanning electron microscope was utilized to observe the microscopic structure of the composites, and it revealed an exceptional homogeneous mixture of nano-SiO_2 particles in the resin epoxy matrix. Afterward, high-velocity impact tests were carried out using a single-stage gas gun test machine. A spherical steel projectile with a diameter of 8.7 mm was used for the test with a speed of 235 m/s. The experimental results indicated that adding 1-3 wt% of nano-SiO_2 into the matrix remarkably increased the impact resistance of the composite. Moreover, the results showed that when the projectile collides with the core of the sandwich panel, it remains in the sandwich panel and its output velocity becomes zero, while when the projectile does not collide with the core, its output velocity is not zero. In order to validate the results, the experimental data were compared to the finite element models, and good agreement was observed.