Investigation on the high-speed impact response of thermoplastic CF/PEEK sandwich structure with cross-grid cores

Aiming at the problem of water vapor condensation caused by the unit cell sealing of traditional grid core materials, a thermoplastic CF/PEEK sandwich structure with cross-grid cores was proposed. The finite element analysis model of high-speed impact and progressive damage of sandwich panels with cross-grid cores is established. The model is used to study the high-speed impact response characteristics of sandwich panels, to explore the influence of panel geometric parameters on its high-speed impact resistance, and to discuss the energy absorption of panels at different impact velocities. In addition, compared with the traditional honeycomb sandwich panel, the advantages and disadvantages of energy absorption efficiency and impedance impact are compared. The results show that the thermoplastic CF/PEEK sandwich structures with cross-grid cores were proposed to have an attenuation effect on the impact and can provide some protection for the object located behind the panel. The main contributors to its impact energy absorption are the front and rear panels. Once a certain speed limit is reached, the energy absorption rate of the front and rear panels is basically the same. The maximum strain at the front of the sandwich panel is about 5%. In addition, the sandwich structure has a better impedance effect on high-speed impact load.