Li X.,Donghua University |
Xi Y.,Shanghai JiaoTong University |
Xi Y.,Key Laboratory of High Performance Fibers and Products
2014 13th International Conference on Control Automation Robotics and Vision, ICARCV 2014 | Year: 2014
In this paper, the information flow topology is regulated under the precondition that each agent can only utilize the information restricted by the physical communication channels. The objective topology is investigated under the framework of double-layer structures and is finally described by an optimal problem involving the eigenvalues on each layer. By introducing the element distance of eigenvector corresponding to the eigenvalues, the first layer in hierarchy is constructed, which furthermore induces the algorithm of double-layer topology design. Theoretical analysis and numerical simulations are provided to demonstrate the validity of the developed algorithms. © 2014 IEEE.
Tang M.,Donghua University |
Tang M.,Key Laboratory of High Performance Fibers and Products |
Li X.,Donghua University |
Li X.,Key Laboratory of System Control and Information Processing |
And 3 more authors.
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2013
The convergence speed of multi-agent system is a focused issue in the consensus problem. The traditional consensus algorithm is generally discussed on the single-layer topology. The spectral partitioning algorithm of the complex network and NF algorithm was applied to the optimal decomposition problem of the multi-agent topology and a hierarchical consensus algorithm based on the community decomposition was proposed in this paper. By converting the single-layer consensus problem of the multi-agent system to multi-layer consensus problem, the convergence speed is effectively improved on the premise of maintaining the original topology constraints .The effectiveness of two types of algorithms is demonstrated by simulations compared with the classic model. Then the comparison between the spectral partitioning method and NF algorithm applied to the optimal decomposition problem is proposed. © IFAC.
Ji F.,Key Laboratory of High Performance Fibers and Products |
Ji F.,Donghua University |
Hong Y.,Key Laboratory of High Performance Fibers and Products |
Hong Y.,Donghua University |
And 9 more authors.
Journal of Adhesion Science and Technology | Year: 2012
In order to investigate how coatings of glycerol affects atmospheric pressure plasma treatment, ultra high molecular weight polyethylene (UHMWPE) fibers were first pretreated with 0.2 and 0.6 mol/l glycerol solutions, respectively, and then were modified by an atmospheric pressure plasma jet (APPJ) using helium as the carrier gas with a flow rate of 20 l/min, discharge power of 30 W and a radio frequency of 13.56 MHz. After the plasma treatment, scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis revealed that the glycerol coated-APPJ treated samples possessed smoother surface than the APPJ directly treated samples. The X-ray photoelectron spectroscopy (XPS) analysis indicated that the changed content of oxygen containing groups on the surface of the glycerol coated groups compared with the non-glycerol coated group was mainly due to the remaining glycerol on the fiber surfaces. The water contact angle test revealed that the wettability of the glycerol coated-APPJ treated fibers decreased slightly in comparison with the APPJ directly treated fibers. Furthermore, the microbond pull-out test indicated that the interfacial bonding of the fiber to epoxy resin decreased when the fiber was pretreated with glycerol before plasma treatment. Therefore, it was concluded that the presence of glycerol on fiber surface weakened the effectiveness of APPJ treatment of UHMWPE fibers in improving the interfacial bonding to epoxy. This was mainly attributed to the consumption of plasma energy in etching the glycerol layer on the fiber surface and a weak interfacial layer due to the presence of residual glycerol. © 2012 Copyright Taylor and Francis Group, LLC.
Zhao Y.,Key Laboratory of High Performance Fibers and Products |
Zhang C.,Donghua University |
Shao X.,Georgia Institute of Technology |
Wang Y.,Georgia Institute of Technology |
Qiu Y.,Key Laboratory of High Performance Fibers and Products
Journal of Adhesion Science and Technology | Year: 2012
In this work the effect of atmospheric plasma treatment on carbon fiber has been studied. The carbon fibers were treated for 1, 3 and 5 min with a He/O 2 dielectric barrier discharge atmospheric pressure plasma. The fiber surface morphology, surface chemical composition and interfacial shear strength between the carbon fiber and epoxy resin were investigated using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and the single fiber composite fragmentation test. Compared to untreated carbon fibers, the plasma treated fiber surfaces exhibited surface morphological and surface composition changes. The fiber surfaces were found to be roughened, the oxygen content on the fiber surfaces increased, and the interfacial shear strength (IFSS) improved after the atmospheric pressure plasma treatment. The fiber strength showed no significant changes after the plasma treatment. © Koninklijke Brill NV, Leiden, 2011.
Xie J.,Key Laboratory of High Performance Fibers and Products |
Xie J.,Donghua University |
Xin D.,Key Laboratory of High Performance Fibers and Products |
Xin D.,Donghua University |
And 12 more authors.
Surface and Coatings Technology | Year: 2011
Plasma treatment is frequently used to modify carbon fiber surfaces to improve adhesion of the fiber to matrices although it may also influence carbon fiber tensile strength. In order to determine the effect of atmospheric pressure plasma treatment on carbon fiber tensile strength and interfacial bonding strength to polyimide, polyacrylonitrile (PAN) based carbon fibers are treated with atmospheric pressure oxygen/helium plasmas for different durations. Tensile strength change of the fiber is studied at different gage lengths before and after the plasma treatment. Interfacial bonding between the carbon fiber and a thermoplastic polyimide matrix is evaluated using a single fiber composite test system. Weibull analysis of the single fiber tensile test data shows no obvious changes in the tensile strength at short gage lengths after plasma treatment while the fiber strength tends to decrease at larger gage lengths. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that the plasma treatments roughen the fiber surfaces. X-ray photoelectron spectroscopy (XPS) analysis of fiber surface shows a significant increase of oxygen concentration after plasma treatment and the oxygen containing functional groups reach their maximum levels after 32 s treatment time and further increasing treatment time does not achieve a higher level of oxidation. Plasma treatments decrease dynamic water contact angles and increase the surface energy of the carbon fibers as measured by the modified Wilhelmy method. The interfacial shear strength is improved 21% after the atmospheric pressure plasma treatment for 32 s. It is concluded that the increase of oxygen containing functional groups and changing of the surface topology may contribute collectively to the improvement of fiber/resin interfacial adhesion. © 2011 Elsevier B.V.
Xu F.,Key Laboratory of High Performance Fibers and Products |
Xu F.,Donghua University |
Yao L.,Key Laboratory of High Performance Fibers and Products |
Yao L.,Donghua University |
And 4 more authors.
Composites Part B: Engineering | Year: 2012
A three-dimensionally integrated microstrip antenna (3DIMA) is a microstrip antenna woven into the three-dimensional woven composite for load bearing while functioning as an antenna. In this study, the effect of conductive yarn crimp on electromagnetic performance of 3DIMAs are investigated by designing, simulating and experimental testing of two microstrip antennas with different patch woven structures: one woven in plain weave pattern with most yarn crimp and the other woven orthogonally without yarn crimp. The measured voltage standing wave ratio (VSWR) of the crimp free 3DIMA was 1.05 at the resonant frequency of 1.31 GHz; while that of the crimped 3DIMA was 1.78 at the resonant frequency of 1.41 GHz. In addition, the measured radiation pattern of the crimp free 3DIMA in its radiating patch has smaller back lobe and side lobes than those of the crimped 3DIMA. This result indicates that yarn crimp may have a negative impact on electromagnetic performance of textile structural antennas. © 2011 Elsevier Ltd. All rights reserved.