Research Article
Dynamic Characters of Stiffened Composite Conoidal Shell Roofs with Cutouts: Design Aids and Selection Guidelines
Table 6
Clamping options for +45/−45/+45/−45 conoidal shells with central cutouts having
ratio 0.2.
| Number of sides to be clamped | Clamped edges | Improvement of frequencies with respect to point supported shells | Marks indicating the efficiencies of number of restraints |
| 0 | Corner point supported | — | 0 |
| 0 | Simply supported no edges clamped (SSSS) | Marked improvement | 52 |
| 1 | (a) Higher parabolic edge along (SSCS) | Marked improvement | 65 | (b) Lower parabolic edge along (CSSS) | Marked improvement | 64 | (c) One straight edge along (SSSC) | Marked improvement | 66 |
| 2 | (a) Two alternate edges including the higher and lower parabolic edges and (CSCS) | Remarkable improvement | 81 | (b) 2 straight edges along and (SCSC) | Remarkable improvement | 83 | (c) Any two edges except for the above option (CSSC, CCSS) | Remarkable improvement | 77–79 |
| 3 | 3 edges including the two parabolic edges (CSCC, CCCS) | Remarkable improvement | 86–89 | 3 edges excluding the higher parabolic edge along (CCSC) | Frequency attains more than a fully clamped shell. | 107 |
| 4 | All sides (CCCC) | Remarkable improvement | 100 |
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