The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
Ge Wang - One of the best experts on this subject based on the ideXlab platform.
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Plastic mechanism analysis of structural performances for stiffeners on bottom longitudinal web girders during a shoal Grounding Accident
Marine Structures, 2015Co-Authors: Ge WangAbstract:Abstract A theoretical model is introduced in this paper for structural performance of stiffeners on double-bottom longitudinal girders in a shoal Grounding Accident. Major emphasis is placed on establishing the characteristic deformation mechanism of stiffeners and identifying major energy dissipation patterns. Numerical simulations using the LS-DYNA nonlinear finite-element program were carried out to examine thoroughly the progressive deformation process during sliding deformation. Stiffener deformations were observed to fall into two categories: stiffeners fully contacted with the indenter, and stiffeners subjected to indirect deformation due to energy transfer from attached girders. Grounding performance of stiffeners is substantially influenced by that of the attached plating, and therefore a review of the existing deformation models of longitudinal girders (i.e. Simonsen 1997, Midtun 2006 and Hong 2008) was included. Hong's model of bottom girders was found not capable of representing the effects of stiffeners, and a new model of girders was thus developed. Based on observation of the numerical deformation process and the new analytical girder model, a kinematically admissible model of stiffeners on bottom longitudinal girders was built. Using the methods of plastic mechanism analysis, simplified analytical expressions for energy dissipation by girder-attached stiffeners, both fully contacted and noncontacted, were formulated, and equations for Grounding resistance were subsequently obtained. The theoretical expressions agree favorably with results from nonlinear finite-element simulations and capture two significant characteristics of the problem: that energy varies little with indentation for stiffeners that fully contacting the indenter, and that energy is independent of slope angle for indirectly deformed stiffeners. The proposed theoretical model helps to predict analytically shoal Grounding performance of stiffeners on longitudinal girders with reasonable accuracy.
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an analysis of structural performances for bottom longitudinal girder and attached stiffeners during shoal Grounding Accident
ASME 2013 32nd International Conference on Ocean Offshore and Arctic Engineering, 2013Co-Authors: Ge Wang, Kun LiuAbstract:Simplified analytical methods have been considered fairly efficient for assessing the structural performances during collision and Grounding of ships. This paper is centered on modeling of bottom girders and the attached stiffeners during shoal Grounding Accidents. The published researches on the behavior of bottom girders during shoal Groundings were reviewed. Numerical analyses using the code LS_DYNA were conducted for understanding the behavior of bottom girders and the attached stiffeners. A parametric study of the influencing factors was conducted. Simulation included a wide range of sloping angles and indentations. The Grounding responses of stiffeners were also presented. The results and conclusions from this paper are preparations for a subsequent establishment of new refined simplified models of bottom longitudinal girders and the attached stiffeners during shoal Grounding Accidents.Copyright © 2013 by ASME
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Plastic Mechanism Analysis of Structural Performances for Stiffen- ers on a Typical Double Bottom Structure during Shoal Grounding Accident
2013Co-Authors: Zhaolong Yu, Zhiqiang Hu, Ge WangAbstract:This paper main ly deals with the structural responses of stiffeners on a typical tanker double bottom structure, which consists of three majo r stiffened components: the bottom plating, transverse floors and longitudinal girders, when Grounding over the “shoal” type seabed o bstacles. A prevailing method is to smear the stiffeners into the plating thickness and thus includes the role of stiffeners during an Accidental action. Ho wever, this method may not provide convincing pred ictive accuracy of the stiffener performances, and the collapse pattern cannot be tracked. Therefore, theoretical models are built for 3 majo r types of stiffeners, providing deep insight of the deformation patterns with reasonable predictive accuracy. The established theoretical models are based on a careful study of the progressive defo rmat ion process of numerical simu lations using the code LS_DYNA. Using the plastic analytical method, majo r plastic analysis strategy for each stiffener type is introduced and discussed. This set of theoretical models will contribute substantially to the establishment of efficient tools for fast and reliable assessment of the performances of ship double bottom structures during sliding Grounding.
Kun Liu - One of the best experts on this subject based on the ideXlab platform.
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an analysis of structural performances for bottom longitudinal girder and attached stiffeners during shoal Grounding Accident
ASME 2013 32nd International Conference on Ocean Offshore and Arctic Engineering, 2013Co-Authors: Ge Wang, Kun LiuAbstract:Simplified analytical methods have been considered fairly efficient for assessing the structural performances during collision and Grounding of ships. This paper is centered on modeling of bottom girders and the attached stiffeners during shoal Grounding Accidents. The published researches on the behavior of bottom girders during shoal Groundings were reviewed. Numerical analyses using the code LS_DYNA were conducted for understanding the behavior of bottom girders and the attached stiffeners. A parametric study of the influencing factors was conducted. Simulation included a wide range of sloping angles and indentations. The Grounding responses of stiffeners were also presented. The results and conclusions from this paper are preparations for a subsequent establishment of new refined simplified models of bottom longitudinal girders and the attached stiffeners during shoal Grounding Accidents.Copyright © 2013 by ASME
He Bin - One of the best experts on this subject based on the ideXlab platform.
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analysis and treatment of one two point Grounding Accident in ta secondary circuit
Journal of Hebei Engineering and Technical College, 2011Co-Authors: He BinAbstract:As for one false tripping Accident caused by two-point Grounding in TA secondary circuit,this paper analyzes the Accident reason and the harm caused by two-point Grounding.At last,it proposes the related protective measures taken in the operation and maintenance of substations.
Zhang Daji - One of the best experts on this subject based on the ideXlab platform.
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Analysis and Prevention of Two-Point Grounding Accident in Secondary Circuit of Instrument Transformer
Energy and Energy Conservation, 2015Co-Authors: Zhang DajiAbstract:Analyzed the reasons of two-point Grounding Accident in secondary circuit of instrument transformer,analyzed how to connect various instrument transformers in order to avoid the two-point Grounding Accidents in secondary circuit,and elaborated how to avoid the two-point Grounding Accidents in design,installation,commissioning,operation and maintenance in details.
Pentti Kujala - One of the best experts on this subject based on the ideXlab platform.
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usability of Accident and incident reports for evidence based risk modeling a case study on ship Grounding reports
Safety Science, 2015Co-Authors: Arsham Mazaheri, Jakub Montewka, Jari Nisula, Pentti KujalaAbstract:This paper presents study of 115 Grounding Accident reports from the Safety Investigation Authority of Finland and Marine Accident Investigation Branch of the UK, as well as 163 near-miss Grounding reports from ForeSea and Finnpilot incident databases. The objective was to find the type of knowledge that can be extracted from such sources and discuss the usability of Accident and incident reports for evidence-based risk modeling. A new version of Human Factors Analysis and Classification System (HFACS) is introduced as a framework to review the Accident reports. The new positive taxonomy as Safety Factors, which are based on high level positive functions that are prerequisite for safe transport operations, is used for reviewing the incident reports. Accident reports are shown as a reliable source of evidence to extract the most significant contributing factors in the events. Mandatory incident reports are considered useful for understanding the effective barriers as risk control measures. Voluntary incident reports, though, are seen as not very reliable in their current form to be used for evidence-based risk modeling.
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correlation between the ship Grounding Accident and the ship traffic a case study based on the statistics of the gulf of finland
TransNav: International Journal on Marine Navigation and Safety of Sea Transportation, 2013Co-Authors: Arsham Mazaheri, Jakub Montewka, Pentti KujalaAbstract:Ship traffic is one of the factors that is presented in almost all of the existing Grounding models, and is considered as one of the factors on the likelihood of a Grounding Accident. This effect in Grounding Accidents is mostly accepted by experts as common sense or simply by just generalizing the ship-ship collision cases to Grounding Accidents. There is no available research on the actual causal link between the ship traffic and Grounding Accident in the literature. In this paper, the authors have utilized the statistical analysis on historical Grounding Accident data in the Gulf of Finland between the years 1989 and 2010 and the AIS data of the same area in year 2010, as the source of ship traffic data, to investigate the possible existence of any correlation between the ship traffic and the Grounding Accident. The results show that for the studied area (Gulf of Finland) there is no correlation between the traffic density and the Grounding Accident. However, the possibility of the existence of a minor relation between the traffic distribution and Grounding Accident is shown by the result. This finding, however, needs further investigation for more clarification.
