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Sun S.-L.,Shanghai JiaoTong University | Hu J.,Harbin Engineering University | Hu J.-Z.,Shanghai Waigaoqiao Shipbuilding Co.
Chuan Bo Li Xue/Journal of Ship Mechanics | Year: 2013

A doubly asymptotic approximation for the governing wave equation was adopted to study the initial impact problem of a compressible water column on an elastic plate. The governing equation is solved by a boundary element method and non-linear boundary conditions are used to update the unknown free surface. Numerical results are compared with analytic solutions by Korobkin (2008) under the same linear boundary conditions, to study the influence of the doubly asymptotic approximation on the numerical results and testify its accuracy, which shows that good agreements are found. The influence of the non-linear boundary conditions on the displacements and the pressure of the plate center is analyzed and discussed.

Tao N.-R.,Shanghai JiaoTong University | Jiang Z.-H.,Shanghai JiaoTong University | Liu J.-F.,Shanghai Waigaoqiao Shipbuilding Co.
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2010

Spatial scheduling problem as key resource scheduling problem was studied. Differences between spatial scheduling problem and three-Dimensional Bin Packing Problem (3D-BPP) were compared. Based on 3D spatial scheduling with time window as constraint, an improved heuristic positioning rules based on Extreme Points (EP) was proposed. Optimization algorithm based on tabu search and EP-based positioning rules was presented. Finally, a simulation experiment was provided to illustrate the effectiveness of the proposed approach.

Huang Y.,Shanghai JiaoTong University | Jiang Z.,Shanghai JiaoTong University | He C.,Shanghai Waigaoqiao Shipbuilding Co. | Song B.,Shanghai JiaoTong University | Liu L.,Shanghai JiaoTong University
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture | Year: 2016

In the process of product design, it is usually difficult for engineers to find and reuse others' lesson-learned knowledge, which is usually not well collected by an enterprise. This study proposes a model of an inner-enterprise wiki system integrated with a semantic search framework to support the accumulation and reuse of lesson-learned knowledge in product design. The accumulated wiki web pages in inner-enterprise wiki system can be viewed as a large lesson-learned knowledge repository, which stores engineers' wisdom of product design and is the basis of semantic search for knowledge reuse. The semantic-based knowledge search mechanism of inner-enterprise wiki system is presented, which can overcome limitations of traditional keyword-based search in existing wiki systems. To validate our approach, an innerenterprise wiki system implementation is introduced and some experiments are done. Effectiveness of semantic search mechanism in inner-enterprise wiki system is verified from several viewpoints such as comparison of precision and recall between proposed method and a keyword-based one. The performance of utilizing inner-enterprise wiki system for knowledge reuse is evaluated and the results show that inner-enterprise wiki system can improve the performance of learning. The promising results confirm the feasibility of our approach in helping engineers to better reuse needed lesson-learned knowledge. © IMechE 2014.

Yang Y.,Shanghai Waigaoqiao Shipbuilding Co. | Huang S.,Harbin Engineering University
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University | Year: 2016

Based on research of existing methods for calculating mooring line damping, in this paper, we introduce an improved quasi-static method. First, we calculate the mooring line damping for several series of load cases using the Huse quasi-static method, Liu quasi-static method, and the fully dynamic finite element method. Then, in the calculation of the two quasi-static methods, we take into account the horizontal displacement of the mooring line element, and again calculate the mooring line damping, since it is significant in the fairlead position. Finally, we analyze the results and compare them to better understand the features and disadvantages of the various methods. After verification, we introduce a improved quasi-static method. This new method demonstrates acceptable accuracy and reliability. The results obtained are similar to those generated by the finite element method. This method can be regarded as an effective auxiliary means for calculating mooring line damping. © 2016, Editorial Department of Journal of HEU. All right reserved.

Miao Z.-M.,Wuhan University of Technology | Zhang H.-S.,Wuhan University of Technology | Wu H.-F.,Wuhan Branch of China Classification Society | Ma T.,Shanghai Waigaoqiao Shipbuilding Co.
Ships and Offshore Structures | Year: 2010

The module stool is a key structure to link the module and the deck in floating production, storage and off-loading (FPSO). The welded joints of the module stool should be guaranteed to possess enough toughness against cracking and rupture. Based on the international standard BS 7448 and DNV-OS-C401, a low temperature (-18°C) crack tip opening displacement (CTOD) test has been conducted on the weld centre and the fusion line of the module stool of a 300 kt FPSO, to be used in the Bohai PL19-3 offshore oil field. The results show that the CTOD values of the specimens of the module stools whose crack tips are located in the weld centre and the fusion lines, respectively (welded with preliminary welding procedure specification), meet the requirements of DNV-OS-C401 (not less than 0.150 mm). Therefore, the preliminary welding procedure specification test can be used to weld the module stool for which no further heat treatment is needed. Accordingly, the quality of the module stools is assured, the fabrication efficiency is improved and the production cost is reduced.

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