Research Article
Behaviour and Optimization Aids of Composite Stiffened Hypar Shell Roofs with Cutout under Free Vibration
Table 6
Clamping options for +45/−45/+45/−45 hypar shells with central cutouts having ratio 0.2.
| Number of sides to be clamped | Clamped edges | Improvement of frequencies with respect to simply supported shells | Marks indicating the efficiencies of clamping |
| 0 | Simply supported no edges clamped (SSSS) | — | 0 |
| 1 | (a) Along (CSSS) | Slight improvement | 9 | (b) Along (SSCS) | Slight improvement | 9 | (c) Along (SSSC) | Slight improvement | 9 |
| 2 | (a) Two alternate edges (CSCS, SCSC) | Good improvement | 17 | (b) Two adjacent edges (CSSC, CCSS) | Good improvement | 31 |
| 3 | 3 edges excluding CSCC | Very good improvement | 48 | 3 edges excluding CCSC | Very good improvement | 48 | 3 edges excluding CCCS | Very good improvement | 48 |
| 4 | All sides (CCCC) | Frequency attains a maximum value | 100 |
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