飞机典型结构件的声疲劳实验研究

Experimental Study of Sonic Fatigue Failure for Typical Structure Specimens of Aircraft

飞机典型结构件为蒙皮、框和长桁组成的双向双加筋的九格壁板结构。利用高声强行波管系统,以典型试件中心格的第一阶频率为中心、1/3倍频程为带宽的窄带随机谱激励,再现壁板结构的声疲劳破坏方式。通过原始状态的典型试件的两次预试验,发现了原典型结构件的设计缺陷。采用三种方式对原结构框的两端进行了支持加强,得到各种支持状态下的声疲劳破坏形式。

Typical structure specimen of aircraft is composed of skin-frame and skin-joist with bidirectional and dual-stiffened 3 ×3 panels. Its sonic fatigue tests were carried out. The exciting spectrum of sonic fatigue test is a narrowband （bandwidth is 1/3 octave band） random spectrum, the centre frequency of which is the first frequency of centre lattice of typical specimen. Sonic fatigue damages of the panel structure were fulfilled by high acoustic intensity progressive wave tube in order to detect the design fault. By twice pretest of the original typical specimens, the hard faults of primal structures were confirmed. The shape of original typical structure specimen was mended by three supporting measures. Mended specimen sonic fatigue damage was analyzed.