Free Vibration of Laminated Composite Hypar Shell Roofs with Cutouts

Figure 6

Values of non-dimensional fundamental frequency (𝜔) of +45/−45/+45/−45 hypar shell with cutout for different sizes of central cutout and boundary conditions. 𝑎/𝑏=1, 𝑎/ℎ=100, 𝑎^′/𝑎=0.1, 𝑎^′/𝑏^′=1, 𝑐/𝑎=0.2; 𝐸₁₁/𝐸₂₂=25, 𝐺₂₃=0.2𝐸₂₂, 𝐺₁₃=𝐺₁₂=0.5𝐸₂₂, 𝜈₁₂=𝜈₂₁=0.25.