Table 5.

First Buckling Modes of the Strut with Different Flange/web Thickness Ratios.

$\mathit{\eta }={\mathit{t}}_{\mathit{f}}/{\mathit{t}}_{\mathit{w}}$	0.238	0.405	0.625	0.857	1.000
Pcr (N)	2595.8	5678.5	9190.1	10,904	11,258
First Buckling Mode
$\mathit{\eta }={\mathit{t}}_{\mathit{f}}/{\mathit{t}}_{\mathit{w}}$	1.363	1.476	1.600	1.889	2.250
Pcr (N)	11,524	11,492	11,244	9714.3	8009.3
First Buckling Mode