Abstract: An embedded co-cured damping and electromagnetic absorbing composite with multi-layer absorbing prepreg layer and absorbing damping layer was proposed, and the thickness of the absorbing wave prepreg layer and the absorbing damping layer was regularly adjusted to realize different frequency bands. The electromagnetic wave absorption was theoretically analyzed by Matlab using the Matlab. The specific thickness of the absorbing prepreg layer and the absorbing damping layer can be designed according to the specific requirements of the electromagnetic absorbing band. The electromagnetic absorbing test verified the selectivity of the electromagnetic absorbing frequency and the validity and rationality of the theoretical analysis method. Modal test and free decay test obtained the curves of modal parameters and damping loss factors with the thickness of absorbing prepreg. The experimental data show that the electromagnetic absorption frequency changes with the increase of the thickness of the absorbing prepreg layer of the specimen. The natural frequency of the mode increases, the modal damping ratio increases, and the damping loss factor increases.

Key words: frequency selectivity, damping sandwich absorbing composite, modal parameter, damping loss factor