Thermal residual stresses in FSS layer-embedded composite plates in co-cure bonding

The residual stresses occur in the frequency selective surface (FSS)-embedded composite structures after co-curing due to mismatch between the coefficient of thermal expansions between the FSS and composite materials. It is well known that residual stress has a great influence on the strength and fatigue life of the FSS-embedded composite structures. Numerous researches have been reported about residual stresses in the composite structures. However, studies on the residual stresses in the FSS-embedded composite structure have not been widely investigated. Therefore, in this study, the thermal residual stresses of FSS-embedded composite structures were analyzed using finite element analysis, with considering the effect of FSS pattern and size. Various FSS patterns, such as square loop, gridded square loop, and double square loop, are considered in the analysis. The effects of dimensional change of design parameters of FSS pattern on the residual stresses in the hybrid composites were also investigated.