He S.-P.,Wuhan Naval University of Engineering |
Liu G.-F.,Wuhan Naval University of Engineering |
Jin G.-W.,Unit 92537 of PLA
Zhendong Gongcheng Xuebao/Journal of Vibration Engineering | Year: 2014
Noise reduction by means of applying decoupling coating on underwater structures is commonly used in the marine field. Assuming decoupling coating as viscoelastic fluid, a vibration and acoustics model of a simply supported rectangular plate covered by decoupling coating is presented. The model simulates the vibration and acoustic response of the structure which is water-loaded on one side and air backed on the other. The characteristics of vibration and acoustics reduction by the decoupling coating are analyzed, and the influences of the physical parameters of decoupling coating to vibration velocity of base plate and sound radiation power are researched. The results show that: for single flexural mode of plate, 'plate-decoupling coating-water layer' is similar to two-freedom degree system, which has two resonant frequencies and an anti-resonant frequency, and dynamic absorber characteristics are introduced by decoupling coating. Dynamic absorber characteristics could be used to reduce the low-frequency vibration and underwater radiation noise by selecting suitable parameters of decoupling coating.
Ren Z.-Q.,National University of Defense Technology |
Yu Z.-Y.,National University of Defense Technology |
Chen X.,National University of Defense Technology |
Wang Y.-L.,Unit 92537 of PLA
Binggong Xuebao/Acta Armamentarii | Year: 2015
In order to reveal the failure of single-strand wire rope under impact load, the structural elastic-plastic attributes are analyzed by using the dimensional finite element model (FDM). According to the experiment data and wire structure, the parameters of the elastic-plastic model are determined, and a 3D FEM is established. Von Mises stress and plastic strain of the internal wire are deduced by calculating the static loading and impact loading. The results show that the Von Mises stress and plastic strain of the contact area are bigger than those of other areas, which is the main reason for the rope break. © 2015, China Ordnance Society. All right reserved.
Peter B.,Belarusian State University of Informatics and Radioelectronics |
Miao X.,Unit 92537 of PLA |
Li Y.,Shandong University
20th International Congress on Sound and Vibration 2013, ICSV 2013 | Year: 2013
Vibration based condition monitoring and fault diagnosis system can facilitate the reliable use of the critical machinery. To develop such systems, high accuracy needs to be achieved as well as reliability. With the accumulated experience over many years, the presented system in this paper not only solves the traditional vibration control problem, but also delivers the quantitative diagnosis. In our system, the operating conditions are not simply evaluated by the related vibration standard. To make an accurate decision, many informative factors are also evaluated, such as low frequency vibration (frequency less than 0.5x), high frequency (frequency higher than 2 x), the structure of monitored device etc. The thresholds are specific for each unit of monitored device. Furthermore, multiple channels can be effectively fused as the foundation of decision-making. With the operation of machinery, the variation of vibration (such as variation caused by wearing) is also considered in our system. To raise the accuracy of diagnosis, the collected signals are separated as periodic and noise groups. For periodic group, different weighting factors are assigned for each signal. By adopting this approach, the fault can be properly rated and analyzed.
Chen Q.,Unit 92537 of PLA
Journal of Marine Science and Application | Year: 2011
The construction and shape of UUVs are described in the paper. UUV design is the shape of the overall design of unmanned underwater vehicle should first be resolved UUV underwater vehicle directly affects the shape of the resistance and noise, which is related to energy, payload, maneuverability and concealment UUV problem The main characteristic and parameter tables for foreign torpedo shape, flat shape and anomalous shape are also given in the paper. The general layout of typical foreign UUVs is analyzed in detail. And the total layout figure and interior constructive figure are introduced. Torpedo-type because of its good water power and low noise, no one has been the main form of underwater vehicle-like, and many designers are now highly favored because of its stable performance, anti-environmental interference capability. Other irregular shapes designed primarily for the completion of a specific task, according to the specific environment and mission requirements. According to comparing and summarizing, some suggestions and conclusions are presented. © 2011 Harbin Engineering University and Springer-Verlag Berlin Heidelberg.
Luo B.-L.,China Ship Scientific Research Center |
Cai J.-B.,Unit 92537 of PLA |
Zheng S.-W.,Unit 92537 of PLA
Binggong Xuebao/Acta Armamentarii | Year: 2015
The dynamic response of plate rib bulkhead structure under explosion load is numerically simulated. A prediction method of structure response is proposed, and the effects of explosive distance and charge quantity on the structure dynamic response are analyzed. Empirical formulas are obtained by data fitting. The effects of the variations in wall thickness, space between the reinforcements and reinforcement thickness on the antiknock shock capability of the reinforced bulkhead structure are discussed. The analysis indicates that the larger bar spacing and bar thickness improve the antiknock ability of the reinforced bulkhead structure obviously. © 2015, China Ordnance Society. All right reserved.