In this work, a method to eliminate ice on wind turbine blade by using carbon fiber composites was put forward. To prove that this idea is feasible, a carbon fiber composite panel with its ends soaked by the conductive silver paste was fabricated and surface temperature of it at three levels of voltages was measured. The surface temperature of the composite panel increased significantly and finally retained a constant, which shows that the carbon fiber composites can be used to eliminate ice when the glass fabric composite blades are covered by the carbon fiber composites.
In this work, the hybrid fabrics of carbon and quartz fibers as filters were adopted in PMI core sandwich structures for low-observable radomes. The advantages of fabric composite frequency selective surfaces (FCFSSs) are easily fabricated by braiding and shaped into curved surfaces. This paper mainly studied the electromagnetic (EM) transmission characteristics of the low-observable radome wall with composite FSS by 3-dimensional electromagnetic analysis software. First of all, the accuracy of the simulation model composed of up and down composite face sheets, a layer of composite FSS and PMI core was validated by comparing with experimental results. Then, the studies on electromagnetic transmission characteristics of the sandwich structure with composite FSS and the sensitivity analysis about the thickness and permittivity of face sheets and PMI core were carried out. The results show that the sandwich structure with single layer composite FSS can realize the function of frequency selection, limit the reflection at the resonance frequency and decrease the sensitivity of EM transmission loss about the thickness of sandwich structures.
Dynamic response and damage mechanism of two-core sandwich panels with foam and honeycomb cores and glass fiber/epoxy composite sheets under low-velocity transverse impact are investigated. The emphasis is focused on the contact force response and crash mechanism of the two-core sandwich panels. Effects of configurations, impact energy levels and types of the cores on the dynamic response are investigated. A modified drop-test experiment is carried out to obtain contact force history of the two-core sandwich structures under different impact energies. The experimental results show that the 10:10 configurations for both honeycomb and foam core sandwich structures under lower impact energy absorb more impact energy than the other two structures. However, under higher impact energy, the honeycomb core sandwich structures of 15:5 configuration absorbs a little more impact energy than the other two, while for the foam core sandwich structures the 5:15 configuration shows a little better impact resistance. Results also show that when impact energy is low foam core sandwich structures do better in absorbing impact energy than the honeycomb ones.
Highly water-dissolvable Na2SO4 nanorods were prepared by introducing Ca2+ and NO3- as shape-control agents. The diameter of the as-synthesized nanorods was basically in the range of 20-40 nm, and the length was in the range of 500-800 nm. It was also found that Ca2+ can restrict the growth of the nanocrystals on a given face and the NO3- can also selectively adsorb on a given face and favor the growth of the nanocrystals and the Cl- may help to form uniform nanorods. The synthesis procedure was also simple, and the as-synthesized nanorods may provide ideal templates for preparing nanotubular materials.
In this work, a kind of conductive polymer-silver paste was used to fabricate carbon fabric composite frequency selective surfaces (FSS) with four-legged slot elements. Screen printing and 3D engraving process were carried out to coat the conductive polymer-silver paste onto the carbon fabric preform and sculpt composite panels into composite FSSs, respectively. Free space and finite element methods were carried out to measure and calculate the electromagnetic transmission characteristics of the composite FSS, respectively. The calculated results are in good agreement with the experimental data. The cascaded effect in double-layered FSS were investigated by finite element method and design of experiment technique (DOE).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.