“…where EA 0 , EI 0 , and GA s,0 corresponds to the full-cross section whereas the presence of openings is accounted in terms of reduction factors (λ, α, β). For composite structures (composed of two or more materials), EA 0 , EI 0 , GA s,0 may be estimated by adopting the transformed-section method, as shown in Figure 3 ( Kassimali et al, 1986). Reduction factors are computed with the strip method proposed by Pickhaver et al…”