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Wei J.,Shanghai JiaoTong University | Wang H.,Hudong Zhonghua Shipbuilding Group Co. | Shi S.,Hudong Zhonghua Shipbuilding Group Co. | Huang J.,Shanghai JiaoTong University | Shi K.,Hudong Zhonghua Shipbuilding Group Co.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2016

To promote the mechanical properties of marine high strength steels joints, fiber laser butt welding on 8 mm thick 10CrSiNiCu steel is performed by using filler wire. The microstructures, hardness, tensile strength, bending property and impact energy (at sub-zero temperature) of the welded joints are analyzed. Also, the effects of welding heat input on microstructures, hardness and fracture behavior of the welded joints are also studied. The results show that the microstructure of the weldment mainly consists of martensite+ferrite+bainite, and its hardness is the highest among the welded joint zones. When heat input decreases from 5.00 kJ/cm to 3.64 kJ/cm, the average hardness of weldment increases from 346 HV to 396 HV. Tensile specimens are all broken in base metal. A bending angle of 113° can be reached at room temperature, which is 60° lower than base metal. At the heat input of E=4.20 kJ/cm, the impact energy at fusion line and weld seam reaches its highest value, 95 J and 101 J, respectively. © 2016, Chinese Lasers Press. All right reserved.


Chen X.,Shanghai JiaoTong University | Pang L.,Shanghai JiaoTong University | Tang Y.,Beijing University of Posts and Telecommunications | Yang H.,HuDong ZhongHua Shipbuilding Group Company Ltd | Xue Z.,Shanghai JiaoTong University
2015 International Conference on Cyber Security of Smart Cities, Industrial Control System and Communications, SSIC 2015 - Proceedings | Year: 2015

Security is an important issue in the field of wireless channel. In this paper, the security problem of Gaussian MIMO wireless hybrid channel is considered where a transmitter with multiple antennas sends information to an intended receiver with one antenna in the presence of an eavesdropper with multiple antennas. Through utilizing some of the power to produce 'artificial noise', the transmitter can only degrade the eavesdropper's channel to ensure the security of the communication. But there is an inherent weakness in this scheme. Then a Hybrid Blind Space Elimination (HBSE) scheme is proposed and proved to fix the design flaw in order to strengthen the original scheme. © 2015 IEEE.


Wu Y.,Shanghai JiaoTong University | Wu Y.,Shanghai Key Laboratory of Materials Laser Processing and Modification | Cai Y.,Shanghai JiaoTong University | Cai Y.,Shanghai Key Laboratory of Materials Laser Processing and Modification | And 4 more authors.
Materials and Design | Year: 2015

The dissimilar joints between SA553 and SUS304 were produced by CO2 laser welding with the ERNiMo-8 and ER308L filler wire. After welding parameters were optimized, qualified weld formations were made. Investigation on the microstructure showed that there were dual phases (martensite and austenite) in the ER308L weld, but only austenite in the ERNiMo-8 weld. For both joints, not only the microstructure gradient, but also the element gradient was observed near interfaces between weld metals and base metals. The Charpy impact and tensile test at room (25°C) and low temperature (-196°C) was implemented. The cryogenic impact energy of the ER308L weldment was 51J, lower than the value (84J) of the ERNiMo-8 weldment. The corresponding cryogenic tensile strength of the two weldments was 1070MPa and 960MPa, respectively. The cryogenic tensile properties of both weldments were rather higher than requirements in the relevant standards. The ERNiMo-8 weldment showed relatively better comprehensive performance when the cryogenic toughness was considered. © 2015 Elsevier Ltd.


Huang J.-L.,Jimei University | Xiang Y.-B.,Jimei University | Qiao Y.-Z.,Hudong Zhonghua Shipbuilding Group Co. | Yin Z.-B.,Jimei University
Dalian Haishi Daxue Xuebao/Journal of Dalian Maritime University | Year: 2015

A nonlinear simulation model of 4190 type turbocharged 4-stroke marine diesel engine was built based on MATLAB/Simulink platform, and the simulation calculation of air intake and exhaust system was carried out. Taking 4190ZLC-2 type marine diesel engine as example, the correctness of the simulation model of diesel engine was verified by comparing the simulation results with the test ones. Finally, the proposed simulation model was used to study the effects of the intake and exhaust system on the performances of 4190ZLC-2 type diesel engine power, torque, fuel consumption rate as well as charging efficiency. Simulation results indicate that the fuel economy and emission of 4190 type diesel engine achieve the optimal value when the inlet manifold diameter offset +20 mm and exhaust manifold diameter of 65 mm, which provides the basis of performance optimization for the 190 series medium-speed marine diesel engine design. ©, 2015, Editorial Office of Journal of Dalian Maritime University. All right reserved.


Liu J.,Huazhong University of Science and Technology | Liu J.,Collaborative Innovation Center for Advanced Ship and Deep Sea Exploration | Liu J.,Hudong Zhonghua Shipbuilding Group Co. | Xiang L.,Huazhong University of Science and Technology | And 3 more authors.
Composites Part A: Applied Science and Manufacturing | Year: 2015

The effects of temperature on the bending properties and failure mechanism of carbon fiber reinforced polymer composite sandwich structure with pyramidal truss cores were investigated and presented in this paper. The three-point bending tests of composite sandwich structures were performed at seven different temperatures, and the scanning electron microscope was used to examine the fiber-matrix interface properties in order to understand the deformation and failure mechanism. Then the effects of temperature on deformation modes, failure mechanism and bending failure load were studied and analyzed. The results showed that the temperature has visible impact on the deformation modes, failure mechanism, and bending failure load. The bending failure load decreased as temperature increased, which was caused by the degradation of the matrix properties and fiber-matrix interface properties at high temperature. The analytical formulae were also presented to predict the bending stiffness and failure load of composite sandwich structures at different temperatures. © 2015 Elsevier Ltd.All rights reserved.


Liu J.,Huazhong University of Science and Technology | Liu J.,Hudong Zhonghua Shipbuilding Group Co. | Kan T.,Huazhong University of Science and Technology | Lou J.,Ningbo University | And 3 more authors.
Polymer Testing | Year: 2016

An experimental study was conducted to investigate the effect of thermal exposure on indentation behavior of carbon fiber reinforced polymer composite sandwich panel (CFRPCSP) with pyramidal truss cores. Composite sandwich panels were fabricated by the hot press molding method. Subsequently, composite sandwich panels were exposed to different temperatures for 6 h. After thermal exposure, quasi-static indentation tests were carried out at room temperature. Then, the effect of thermal exposure on the failure mechanism, indentation load and energy absorption were analyzed and discussed. The results showed that the indentation load and energy absorption decreased as exposure temperature increased, which was caused by the degradation of the matrix properties and fiber-matrix interface properties at high temperature. In addition to the decrease of the indentation load and energy absorption, the failure modes also changed with exposure temperature. It is expected that this study can provide useful information for the design and application of composite sandwich panel with pyramidal truss cores at high temperature. © 2015 Elsevier Ltd. All rights reserved.


Yang C.,Wuhan Naval University of Engineering | Yang J.,Wuhan Naval University of Engineering | Bian J.,Hudong Zhonghua Shipbuilding Group Co Ltd.
ICRMS'2011 - Safety First, Reliability Primary: Proceedings of 2011 9th International Conference on Reliability, Maintainability and Safety | Year: 2011

Reliability analysis of phased mission system (PMS) is much more complex, because of the s-dependence across the phases for a given component and the dynamic system structure and configuration which usually requires a distinct model for each phase. After reviewing the modeling method of PMS, the problem of state explosion is put forward. Then the PMS modeling method based on interactive Markov chain (IMC) is presented, which composes the RBD model of each phase to an integrated IMC model of PMS. The case shows that the IMC model can achieve the state space shrink by hide operation and weak bissimulation of IMC. © 2011 IEEE.


Wang J.,Hudong Zhonghua Shipbuilding Group Co. | Jin Y.,Hudong Zhonghua Shipbuilding Group Co. | Yang R.,Hudong Zhonghua Shipbuilding Group Co.
Ship Building of China | Year: 2015

Global FEM analysis for a large Container-RORO vessel built by Hudong-Zhonghua shipbuilding group was carried out. By creating a series of vertical forces based on cantilever beam theory, a FE calculation method was adopted to achieve the objective bending moment distribution of the hull girder. FE strength check of hull section modulus was conducted, and potential key regions were forecasted for further global FE analysis. According to ABS global FE analysis guide, long term prediction of wave induced load was performed with ABS-DLA/SFA software series. A group of design waves were defined and the stress distributions were achieved. Local stress in two transition areas near the middle of the RORO cargo was investigated with fine mesh method. In order to solve the problems in local stress concentration, some special designs were taken. The methods presented in the paper may be referenced to other large vessels. © 2015, Editorial Office of Ship Building of China. All right reserved.


Hu Y.,Huazhong University of Science and Technology | Hu Y.,Wuhan Naval University of Engineering | Liu H.,Huazhong University of Science and Technology | Rao Q.,Wuhan Naval University of Engineering | And 3 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2011

N-doped TiO2 nanocrystalline powders were prepared by the sol-gel method using various N precursors, including triethylamine, hydrazine hydrate, ethylenediamine, ammonium hydroxide, and urea. The samples were characterized by X-ray diffraction, N2 adsorption isotherms, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of as-prepared samples under irradiation of visible light (λ > 405 nm) were evaluated by photodecomposition of methyl orange. The alkalinity of N precursor was found to play a key role in the gel process. The N precursor with moderate alkalinity causes TiO2 nanoparticles to be sol-transformed into a loosely agglomerated gel. This transformation facilitates the preparation of an N-doped TiO2 powder with small nanocrystal size, large specific surface area, and high N doping level and results in high visible light photocatalytic activity. The N in TiO2 with N 1s binding energy at 399-400 eV may be assigned to the N-H species located in interstitial sites of TiO2 lattice which is the active N species responsible for the visible light photocatalytic activity. The N species of N 1s peak at ~402 and ~405 eV are ineffective to the visible light photocatalytic activity and may inhibit the photocatalytic activity. Moreover, a TiO2 nanoparticle powder with large specific area can be achieved by using urea as a template and then by using ammonium hydroxide to transform the sol into gel. Copyright © 2011 American Scientific Publishers.


Zhu X.,Huazhong University of Science and Technology | Zhu X.,Hudong Zhonghua Shipbuilding Group Co. | Tang Y.S.,Hudong Zhonghua Shipbuilding Group Co. | Li F.X.,Huazhong University of Science and Technology | Zhao Y.,Huazhong University of Science and Technology
Applied Mechanics and Materials | Year: 2013

The jack-up wind turbine installation vessel is a special kind of vessel for building the offshore wind power farm. The main crane pedestal, which is the supporting structure of the crane on the main deck of the vessel, is always under high level loads when the ship is in operation condition. In this paper, the structural strength analysis of main crane pedestal of the jack-up wind turbine installation vessel was presented. The direct calculated method was used to evaluate the strength of the main crane pedestal. The FE model of main crane pedestal was established with refined mesh, and the adjoining hull structure was also modeled to provide accurate boundary condition. Considering the permanent loads, variable loads (crane loads) and wind loads on the pedestal, the load combinations were defined for the ultimate limit state for every 45 degree. The deformation and stress of the pedestal and the hull structures were calculated and checked. The results showed that all stress results were within the maximum allowable stresses. The critical areas are often located at the link region of hull and pedestal. © (2013) Trans Tech Publications, Switzerland.

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