scispace - formally typeset
Search or ask a question
Journal ArticleDOI

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

TL;DR: In this article, an impact monitoring system based on fiber bragg grating (FBG) sensor is constructed, where the frequency domain information of the signal can be obtained by Fourier transform.
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.
References
More filters
Journal ArticleDOI
TL;DR: In this article, the effect of stacking sequence on impact damage in a carbon fiber/toughened epoxy composite was studied and the residual energy absorbed in delamination propagation was found to increase linearly with increasing total delamination area.

180 citations

Journal ArticleDOI
TL;DR: In this paper, a cylindrical rate stick consisting of multiple high explosive (HE) segments was used to measure the minimum internal fiber pressure required for prompt grating destruction and accurate wavefront position measurement.
Abstract: Measuring detonation wavefront position and velocity changes across material interfaces has been demonstrated using an all-optical chirped fiber Bragg grating approach. An experiment was conducted with a cylindrical rate stick consisting of multiple high explosive (HE) segments. A measurement of detonation position across interfaces of different HE formulations was made for both low and high spatial resolution gratings. The results show the accuracy of measured velocities is increased with the higher resolution gratings. A decaying shock driven into the polymethyl methacrylate (PMMA) segment provided a measure of the minimum internal fiber pressure required for prompt grating destruction and accurate wavefront position measurement.

20 citations

Journal ArticleDOI
TL;DR: In this article, a new simple parameter based design method for designing a CFRP honeycomb sandwich cylinder for spacecraft applications is presented, where the parameters that constitute the design are aspect ratio, ply orientation, ply sequence, number of plies and effective coefficient of thermal expansion of the sandwich construction.

18 citations

Journal ArticleDOI
TL;DR: Wavelet transforms are used to trace the origin of spectral features in the cantilever spectra and calculate force gradients of the tip-sample interaction stiffness.
Abstract: The transient eigenmode structure of an interacting cantilever during a single impact on different surfaces evidences the excitation of higher flexural modes and low frequency oscillations. The frequency shift of the fundamental mode after the tip comes into contact with the sample surface allows calculating the tip–sample interaction stiffness and evidences the role of capillary condensation and surface wettability on the cantilever dynamics. Wavelet transforms are used to trace the origin of spectral features in the cantilever spectra and calculate force gradients of the tip–sample interaction.

12 citations


"Analysis of Energy Density Spectrum..." refers background in this paper

  • ...Daubechies wavelet has the compact support set, the localization ability is strong, and the application precision is high, as shown in a paper [12]....

    [...]