Musical Tone Law Method for the Structural Damage Detection

Table 2

Natural frequencies of steel pipes under various damage cases.

Test cases	1st order	2nd order	3rd order	4th order	5th order	6th order	7th order
Frequency of the intact pipe/Hz	275	541	819	1085	1362	1631	1903
Neighbouring frequency interval of the intact pipe/Hz	—	266	278	266	277	269	272
Frequency of the damaged pipe/Hz	288	538	859	1050	1350	1625	1906
Neighbouring frequency interval of the damaged pipe/Hz	—	250	321	191	300	275	281