Behaviour and Optimization Aids of Composite Stiffened Hypar Shell Roofs with Cutout under Free Vibration

Table 4

Values of “𝑝” for +45/−45/+45/−45 hypar shell.

Boundary conditions	Cutout size (𝑎^/𝑎)
	0	0.1	0.2	0.3	0.4
CCCC	0	0.08	−1.2	−7.4	−16.29
CSCC	0	1.13	−6.11	−21.59	−29.25
CCSC	0	0.67	−5.84	−21.9	−28.99
CCCS	0	0.75	−5.78	−21.96	−29.22
CSSC	0	−0.82	−5.14	−12.44	−24.09
CCSS	0	−0.97	−5.18	−12.77	−24.19
CSCS	0	0.99	0.53	1.53	1.52
SCSC	0	0.93	0.53	−0.01	1.87
CSSS	0	0.77	0.64	1.36	−0.29
SSSC	0	0.74	0.64	1.34	−0.07
SSCS	0	0.58	0.64	1.35	−0.3
SSSS	0	0.44	0.8	1.66	0.36

𝑎/𝑏=1, 𝑎/ℎ=100, 𝑎^/𝑏^=1, 𝑐/𝑎=0.2; 𝐸₁₁/𝐸₂₂ = 25, 𝐺₂₃=0.2𝐸₂₂, 𝐺₁₃=𝐺₁₂=0.5𝐸₂₂, 𝜈₁₂=𝜈₂₁=0.25, 𝑏_𝑠𝑡/ℎ=1, 𝑑_𝑠𝑡/ℎ=2. Each stiffener has a single lamina with fibres along its length.