Abstract: Electromagnetic functional structures have both load-bearing and wave-absorbing properties, and are often used at the edge to reduce electromagnetic scattering. However, electromagnetic functional structures are susceptible to impact and even shock damage during service, which not only compromises their load-bearing performance but also significantly affects their electromagnetic properties. This study focuses on the electromagnetic functional structures. Electromagnetic simulation models were established for various conditions, including intact, penetrating damage, and skin damage. The radar cross sections under different pitch angles in the X-band were analyzed and comprehensively evaluated. By examining the electromagnetic field and power loss density distribution, the mechanism through which damage influences the radar cross section of the structure was further investigated. The results indicate that the effect of damage on the structure’s wave-absorbing performance exhibits significant frequency and angle dependence. Penetrating damage with a front-end radius of 30 mm resulted in a maximum radar cross section increase of 21.65 dB. The radar cross section of the electromagnetic functional structure increased with the size of the damage, and the adverse effects of damage were more pronounced at lower frequencies. The detrimental impact of front-end skin damage was comparable to that of front-end penetrating damage, while damage at the front end had a far greater deteriorating effect on radar cross section than damage at the middle section. For instance, under damage conditions with a radius of 20 mm, the maximum radar cross section increases caused by front-end penetrating damage and skin damage at 8 GHz were 11.67 dB and 12.00 dB, respectively, whereas the maximum radar cross section increase caused by middle-section damage was below 3.05 dB.

Key words: electromagnetic functional structures, damage, electromagnetic simulation, radar cross section, performance evaluation