Analysis of Energy Density Spectrum of Lowvelocity Impact in Honeycomb Sandwich Panel with FBG

Abstract

As a kind of structure commonly used in satellite, carbon fiber composite honeycomb sandwich panels are vulnerable to various kinds of damage, especially low-velocity impact damage in the process of using. In this paper, an impact monitoring system based on Fiber Bragg Grating (FBG) sensor is constructed. The frequency domain information of the signal can be obtained by Fourier transform. Monitoring results of different impact points show that the natural frequency of structure is 110Hz and 380Hz, which amplitude of different natural frequency is changed with position of impact point. The energy status of impact response signal can be obtained by wavelet packet analysis. The monitoring results of the same impact point shows that the change of the sensor signal is obvious in thirteenth order and energy size is related to the distance and angle between the impact point and sensor. 1,2