Vibration Characteristics of Ring-Stiffened Functionally Graded Circular Cylindrical Shells

Table 9

Variation of natural frequencies against circumferential wave number 𝑛, type I 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	24.955	24.881	24.799	24.646	24.496	24.403	24.377
2	29.526	28.439	29.151	29.064	28.968	28.788	28.613	28.504	28.473
3	45.740	44.073	45.161	45.029	44.881	44.605	44.337	44.171	44.124
4	79.445	76.570	78.446	78.217	77.962	77.487	77.024	76.739	76.658
5	126.21	121.65	124.63	124.26	123.86	123.10	122.37	121.92	121.79
6	184.32	177.66	182.00	181.47	180.88	179.78	178.71	178.05	177.86
7	253.29	244.15	250.11	249.38	248.57	247.06	245.59	244.68	244.42
8	332.97	320.96	328.79	327.83	326.77	324.79	322.85	321.66	321.32
9	423.29	408.03	417.98	416.77	415.41	412.90	410.43	408.92	408.49
10	524.21	505.31	517.64	516.14	514.46	511.34	508.29	506.42	505.88