The Influence on Modal Parameters of Thin Cylindrical Shell under Bolt Looseness Boundary

Table 7

Natural frequencies of TCS under BLB with different looseness numbers.

Modal; order	No looseness; (Hz)	Loosen; 1 bolt; (Hz)	Effect degree; (; (%)	Loosen; 2 bolts; (Hz)	Effect degree; (%)	Loosen; 3 bolts; (Hz)	Effect degree; (%)	Loosen; 4 bolts; (Hz)	Effect degree; (%)
1	906.3	888.7		857.9		857.5		827.9
2	980.8	980.0	0	947.1		920.6		886.5
3	1025.7	1051.2	2.5	1021.0		951.8		927.9
4	1072.3	1175.3	9.6	1147.0		1042.2		1045.6
5	1274.0	1218.6		1235.0		1145.1		1143.8
6	1312.8	1309.1		1292.6		1236.2		1233.3
7	1613.8	1612.2		1613.0		1613.2		1612.3
8	1996.3	1990.2		1989.1		1988.0		1989.6