Recovery of wave-absorbing efficiency for honeycomb sandwich structure under penetrating damage via composite patch electromagnetic parameters design

Two-dimensional periodic honeycomb sandwich structure with tunable electromagnetic parameters are widely used in various aviation equipment as wave-absorbing materials. However, harsh service conditions such as aerodynamic loading or heating, bird strikes and lightning strikes may lead to different damage modes (panel damage, core damage or penetrating damage). In the vicinity of the damaged area, electromagnetic wave undergoes complex reflection and scattering, and electromagnetic parameters degrade correspondingly with the increase of damage proportion. In this work, we propose a composite patch-adhesive bonding technique to realize recovery of wave-absorbing efficiency for honeycomb sandwich structure under penetrating damage via composite patch electromagnetic parameters design. Compared with traditional adhesive bonding, composite patch-adhesive bonding technique possess larger repair tolerance, effectively solving the incompatibility of low-frequency and high-frequency band electromagnetic parameters for repair material system. Our study provides valuable insights for the repair of wave-absorbing honeycomb sandwich structure. [Display omitted]