Abstract:
Modern supersonic aeroplanes produce a high-intensity noise level up to 155 dB near the jet nozzles, which is enough to cause acoustical fatigue and failure. We used the electro-pneumatic loudspeaker coupled directly to the travelling-wave tube to produce about 165-170 dB of the high-intensity random sound field in the test section. This paper studied experimentally for three types of the metal sheets, i.e. type L
yl2-CZ-
δ0.8, type L
yl2-CZ-
δ1.0 and type Ʀ1T-0.6. Under such sound field, we observed the whole process) of the crack initation, growth, propagation and failure, and compared the acoustical fatigue of the different structures and obtained experimentally the
Lp-
t curves of the 0.8mm and 1.0mm allumiun sheets, and 0.6 mm stainless steel sheet.