【摘要】 近代高速喷气飞机喷口附近的噪声级高达155分贝.由于在整个飞行过程中飞机尾部处在强噪声环境中,薄板结构因声致振动而产生声疲劳和断裂。我们用气流扬声器直接耦合到行波管,在测试段产生165—170分贝的无规噪声场。对 Ly₁₂-CZ-δ_0.8,Ly₁₂-CZ-δ_1.0和RIT-0.6三种薄板进行了实验研究:观察了裂纹出现和扩展的全过程,比较了不同结构的声疲劳特性,并由实验初步归纳出表述0.8毫米和1.0毫米铝合金板和0.6毫米不锈钢板的噪声场声压级和断裂时间（L_p-t）的关系。更多还原

【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 Lyl2-CZ-δ0.8, type Lyl2-CZ-δ1.0 and type (?)1T-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.更多还原