Reliability Based Design of Multilayered Composites for Electromagnetic Shielding Applications

This paper presents a reliability based design study of multilayered composites for electromagnetic interference shielding applications. In this study, uncertainties in the design and external variables affecting the shielding effectiveness (SE) are modeled based on probability distributions. Monte Carlo simulation is employed at each design point generated via Latin hypercube sampling approach to evaluate the probability of failure from the limit state function. Subsequently, a response surface approximation is employed to approximate the probability of failure in terms of design variables. This approximated polynomial is used to compute the probabilistic constraint in the design optimization. The design problems so formulated are solved using the real-coded genetic algorithm. The plane wave SE theory approach based on transmission line modeling for the multilayer shields in arbitrary polarized and incident direction of electromagnetic wave is adopted for SE calculation. The proposed approach is illustrated through examples by considering the military and commercial shielding requirements.