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Low‐velocity impact performance of notched glass fiber reinforced plastic composites repaired by bonding external composite patches was investigated by experimental and numerical methods. Various patches of different fiber materials such as carbon and glass fiber and thickness were considered under different impact energy levels. The continuum damage mechanics based on a dynamic progressive damage model was using to build the finite element model and cohesive elements were used between the composite patch and notched composite plate. Five different failure criteria based on three‐dimensional Hashin damage models were implemented by the explicit finite element subroutine ABAQUS‐VUMAT with degradation model and used to compare experimental damage areas. The experimental contact force, kinetic energy histories, and experimental damage areas were calculated and compared the numerical ones. While the experimental data confirm the efficiency of the proposed model, they show consistent results with the numerical model. Finally, using the composite patch is succeeded to avoid impact damage. This research provides fundamental support for the appropriate selection of external composite patch type and use of the degradation model with different failure model to achieve high‐efficiency simulation under impact loading.

The low-velocity impact behavior of SiC nanoparticle-glass fiber-reinforced polymer matrix composites (PMC) in terms of different weight fraction of nanoparticle, artificial aging time, and impact energy was investigated in this article. In this context, silicon carbide (SiC-70 nm) ceramic nanoparticle in weight fractions of 0%, 0.1%, 1%, 2%, 3% filled glass fiber-reinforced PMCs were produced by vacuum infusion technique. The specimens were artificially aged in 0, 750, and 1500 h, 85% relative humidity and 70 C in air conditioning cabinet. The after-impact damage regions were obtained using ultrasonic scanning technique for three different impact energies of 10, 20, and 30 J. The weight of specimens was measured at certain periods during aging and the weight change was examined. As the weight fraction and aging time were increased, the impact resistance of specimens decreased. At the beginning of aging period, the weight of specimens increased; however, the increase in weight decreased over time. Ultrasonic scanning results showed that the damage geometry changed and increasing discontinuity with increasing weight fraction and artificial aging time.

Thanks to their superior mechanical properties, polymer matrix composites have gained considerable importance. In order to improve the impact resistance of polymer matrix composite materials, a new hybrid material known as fiber metal laminate (FML) has been developed. The aim of this study was to reveal the effect of stacking sequence (SS), metal volume fraction (MVF), and number of layers on ballistic resistance in fiber metal laminates (FMLs). Four types of FMLs in different sequences and MVF (25% and 50%) were produced with hot press and vacuum. Ballistic tests were carried out with a single stage gas gun system. The absorbed energy was calculated from the energy difference that occurred by taking into account the FMLs entry and exit velocity of the projectile and the projectile mass. Damage types were examined after ballistic testing. It was determined that the stacking sequence and MVF significantly affect the impact resistance of FMLs. It was determined that the metal layer, which first encounters the projectile, compared to the polymer matrix composite, is more effective on the impact resistance of FMLs, and the impact resistance increased with the increase of MVF. In addition, the increase in the number of layers, if the top layers remain the same, adversely affected the impact resistance. It was observed that the first layer that encounters the projectile and the amount of MVF have a significant effect on the ballistic impact strength. As the amount of MVF increases, the ballistic impact resistance increases.