• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.6
• /
• pp.475-481
• /
• 2013

The residual stresses occur in the Frequency Selective Surface(FSS) embedded hybrid composite structures after co-curing due to mismatch among the coefficient of thermal expansions and stiffness values between the FSS and composite materials. The spring backs occur due to these residual stresses. Therefore, in this paper, the spring-backs caused by residual stresses in FSS embedded composite structures were studied with considering effect of symmetric and unsymmetric stacking sequence of composite laminates.

• Composites Research
• /
• v.24 no.1
• /
• pp.37-44
• /
• 2011

In this paper, Particle Swarm Optimization(PSO) is applied to the design of the Frequency Selective Surface(FSS) and residual stresses of hybrid radome is predicted. An equivalent circuit model with Square Loops arrays was derived and then PSO was applied for acquiring the optimized geometrical parameters with proper resonant frequency. Residual stresses occur in the FSS embedded composite structures after cocuring and have a great influence on the strength of the FSS embedded composite structures. They also effect transmission quality because of delamination. Therefore, the thermal residual stresses of FSS embedded composite structures were analyzed using finite element analysis with considering the effects of FSS pattern, and composite stacking sequence.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.2
• /
• pp.123-130
• /
• 2013

In this paper, the delamination and failures in frequency selected surface(FSS) caused by residual stresses in the FSS embedded hybrid composites due to the difference between the coefficients of thermal expansion of components and the transmission characteristic changes due to deformation of FSS patterns by residual stresses were studied. FSS may have different electromagnetic characteristics depending on the type of element, design variables, and arrangement. Design variables of dipole FSS were determined using PSO(Particle Swarm Optimization) to obtain the transmission characteristic for the target resonant frequency. Subsequently, the design variables of other types of N-pole(tripole, cross dipole, and Jerusalem cross) were determined based on the dimensions of the dipole for the comparisons of residual stresses of FSS embedded composite structures and transmission characteristics. In addition, effects of FSS pattern, and stacking sequence of composite laminates were considered.