Experimental Study on Low-Velocity Impact Performance of GFRP Trapezoidal Corrugated Sandwich Structures

Glass fiber trapezoidal corrugated sandwich structures are composed of trapezoidal cores and glass fiber-reinforced polymer (GFRP) panels. A series of low-velocity impact tests were conducted to investigate the impact resistance performance, considering the effects of impact position, impactor shape, and impactor diameter on the damage mechanism of sandwich structures. When the impactor shape and impact energy remain constant, the maximum impact load at the node impact point is higher than at the base, while the displacement of impact at the base is significantly higher than that at the node. Secondly, when the impactor diameter and energy of the impactor are the same, the hemispherical impactor requires less penetration energy to impact the sandwich structure compared to the flat impactor. Comparing the shape of the impactor, it is found that the smaller the contact surface of the impactor, the more concentrated the stress, and the lower the required penetration energy. Finally, when the impactor shape and impact energy are the same, as the diameter of impactor increases, the damage expansion during impacting on the sandwich structure becomes more sufficient, resulting in decreased impact displacement and smaller impact damage caused to the sandwich structure.