Vibration Characteristics of Ring-Stiffened Functionally Graded Circular Cylindrical Shells

Table 11

Variation of natural frequencies against circumferential wave number 𝑛, type II FG cylindrical shell with stainless steel ring stiffeners (𝑚=1, ℎ/𝑅=0.002, 𝐿/𝑅=20, 𝑑/𝑏=1.334).

𝑛	𝑁^𝑆𝑆=0	𝑁^𝑁=0	𝑁=0.5	𝑁=0.7	𝑁=1	𝑁=2	𝑁=5	𝑁=15	𝑁=30
1	25.274	24.348	24.646	24.718	24.799	24.955	25.113	25.214	25.243
2	29.526	28.439	28.790	28.874	28.970	29.152	29.338	29.455	29.490
3	45.740	44.073	44.613	44.742	44.888	45.168	45.451	45.632	45.684
4	79.445	76.570	77.502	77.726	77.978	78.461	78.945	79.259	79.349
5	126.21	121.65	123.12	123.48	123.88	124.65	125.42	125.91	126.06
6	184.32	177.66	179.81	180.34	180.92	182.04	183.16	183.89	184.09
7	253.29	244.15	247.11	247.82	248.63	250.16	251.70	252.70	252.99
8	332.97	320.96	324.85	325.79	326.85	328.86	330.88	332.20	332.57
9	423.29	408.03	412.97	414.16	415.51	418.07	420.64	422.30	422.78
10	524.21	505.31	511.44	512.91	514.57	517.74	520.92	522.99	523.58