Design of electromagnetic wave absorbing sandwich composite for secondary bonding application

ABSTRACT

In this study, a novel electromagnetic (EM) wave absorbing composite sandwich structure and its application process are proposed. The composite sandwich can be applied to the outer part of structures as a final surface treatment through a secondary bonding process, and this covers all the surface components that illuminate the incident EM waves. This process improves the structural material properties of the original components and their durability against the environment in contrast to EM wave absorbing paint or patch. With the help of EM wave absorbing characteristics and continuous impedance of the composite sandwich structures, the EM signals from reflection, diffraction, and scatter decrease effectively. The outer skin of the composite sandwich includes a resistive periodic patterned sheet prepared using printed electronics, and a low-dielectric foam is adopted as the core material. This composite is designed based on the equivalent circuit theory and is subsequently fabricated. The EM characteristics are tested after application on an aircraft skin structure through a secondary bonding process. The measurement of reflection loss and image processing of the reflected signal show that this composite and application process decrease the EM wave reflections from the original structure significantly.

KEYWORDS:

• Functional composite
• sandwich structure
• electromagnetic wave absorber
• radar cross-section

Additional information

Notes on contributors

Won-Jun Lee

Won-Jun Lee He works for ADD (Agency for Defense Development) in KOREA. He got Ph.D. in aerospace engineering department from KAIST (Korea Advanced Institute of Science and Technology) in 2008. His research theme is aircraft structure design, and specific research topics are multi-functional composites, stealth materials, and EM wave propagation analysis.

Sang-Min Baek

Sang-Min Baek He works for ADD (Agency for Defense Development) in KOREA. He got MS. in mechanical engineering department from KAIST (Korea Advanced Institute of Science and Technology) in 2013. His research topics are rotorcraft design, EM wave field analysis, and optimization.

Sang-Yong Kim

Sang-Yong Kim He works for ADD (Agency for Defense Development) in KOREA. He got MS. in mechanical engineering department from Yonsei University in 2009. His research topics are structural dynamics, aircraft structure design, and multi-functional composite materials.