scholarly journals Analysis and Disposal of Typical Breakdown Failure for Resin Impregnated Paper Bushing in the Valve Side of HVDC Converter Transformer

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4303 ◽  
Author(s):  
Hao Tang ◽  
Guangning Wu ◽  
Ming Chen ◽  
Jiang Deng ◽  
Xining Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fault Current ◽  
Special Device ◽  
Test Results ◽  
The Finite Element Method ◽  
Load Current ◽  
High Voltage Direct Current ◽  
Root Cause ◽  
Current Characteristics

This paper presents analysis, diagnosis and disposal with a typical internal breakdown failure of the resin impregnated paper (RIP) valve side bushing in high voltage direct current (HVDC) converter transformer. Based on the analysis of fault current characteristics at the time of the RIP valve side bushing failure, and field test results of insulation parameters, a method of diagnosing typical breakdown failures of valve side bushings is proposed. Through disassembly inspection of the internal overheating and arcing traces on the failure bushing, the root cause of this typical breakdown failure is found, which is upper axial flashover along the RIP condenser/SF6 interface caused by the abnormal contact of two current-carrying conductive tubes. Temperature distribution inside the bushing with an abnormal contact resistance between the copper conductive tube and aluminum conductive tube under different load current is simulated by using the finite element method. An special device is also developed for repairing defective bushing on-site, and 75 bushings with conductive contact defects have been repaired on the premise of not pushing converter transformers away from the valve hall and even without pulling out defective bushings.

Design of a 33-Knot Aluminum Catamaran Ferry

2000 ◽  
Vol 37 (02) ◽  
pp. 88-99
Author(s):  
R. G. Latorre ◽  
P. D. Herrington
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Frame Structure ◽  
Test Results ◽  
Finite Element Analyses ◽  
The Finite Element Method ◽  
Floating Frame ◽  
Good Agreement ◽  
Panel Design

This paper presents the results of an investigation on the suitability of using hull panels with alternating fixed and floating frames for a 30–40 knot aluminum catamaran ferry. A prototype 4.6 m × 1.8 m bottom hull panel with alternating frames is analyzed numerically and physically tested. The corresponding finite-element analyses and test results are in good agreement. The results show that the floating frame hull panel design is a feasible structure for an aluminum catamaran. The floating frame structure was then used for a 33-knot, 250-passenger aluminum catamaran ferry designed to meet the ABS High Speed Craft rules. A midship section of the catamaran hull was analyzed using the finite-element method. Catamaran weight estimates, heave and pitch motions, and powering estimates are also provided. The results show that the alternating floating frame structure was within the ABS rules stress allowables.

scholarly journals Composite beams with indented construction joint – comparison of results of laboratory tests and numerical analysis

2020 ◽  
Vol 19 (4) ◽  
pp. 031-042
Author(s):  
Grzegorz Sadowski ◽  
Piotr Wiliński ◽  
Anna Halicka
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Comparative Analysis ◽  
Composite Beam ◽  
Laboratory Tests ◽  
Virtual Model ◽  
Test Results ◽  
Shear Cracks ◽  
The Finite Element Method ◽  
Laboratory Test Results

The paper presents a comparative analysis of the behaviour of a composite beam, consisted of a precast element with indented surface and new concrete layer, subjected to 4-point bending. The results obtained from the virtual model of the beam created using the finite element method (Abaqus/CEA 2019 software) were compared with the laboratory test results obtained with use of the digital image correlation (DIC) method for identifying the crack pattern. The virtual model of composite beam was calibrated by the choice of interface parameters ensuring that the value of load resulting in delamination between concrete layers was close to that value obtained in the laboratory tests. The comparative analysis showed that the pattern of bending and shear cracks and the pattern of interface crack obtained with the finite element method reflect the laboratory test results properly. It can be assumed that the crack between concrete layers is related to the appearance and propagation of shear cracks. On the basis of FEM analysis it can be concluded that the phenomena identified as “shear friction” and “dowel action” are significantly activated after the interface cracking.

Investigation of API 8 Round Casing Connection Performance—Part III: Sealability and Torque

1984 ◽  
Vol 106 (1) ◽  
pp. 144-152 ◽  
Author(s):  
W. T. Asbill ◽  
P. D. Pattillo ◽  
W. M. Rogers
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Pressure ◽  
Test Results ◽  
The Finite Element Method ◽  
Middle Portion ◽  
End Effects ◽  
Hoop Stresses ◽  
External Loads ◽  
Pipe Size

The performance of the API LT&C 8 Round casing connection is investigated using 7-in.-29-lb/ft pipe size. Part I showed that the finite element method was applicable for analysis using both a threaded and an unthreaded model. Part II investigated the effects of various thread tapers and external loads on connection hoop stresses. It also evaluated maximum assembly interference based on an assumed criteria. Part III addresses connection sealability based on contact pressure. Geometric end effects are found to be significant in the unthreaded model. Sealability in the middle portion predicted by hand equations is shown to be reasonable. The threaded model shows that tension reduces sealability by disengaging thread stab flanks. Assembly forces are analyzed and, along with the test results, are used to find an equation for torque. The effects of thread taper variations, tension, and pressure on torque are shown.

FEM Analysis and Optimization of Large Load Suspended Platform

2012 ◽  
Vol 569 ◽  
pp. 415-419
Author(s):  
Xi Jian Zheng ◽  
Yong Shang Han ◽  
Zheng Yi Xie
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Fem Analysis ◽  
Element Model ◽  
Test Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Finite Element Model

Based on the Finite Element Method, the suspended platform of temporarily installed suspended access equipment was simplified and the special connection positions were dealt with rigidization and coupling, thus the finite element model of suspended platform was established. Analyzing major structures of finite element model in different section dimensions, the reasonable scheme could be ascertained and the section dimensions of major structures in different materials could be obtained. Combining with the test results, the rationality of finite element analysis could be proved. The study could provide reference for the similar products on design and development.

Study of Material’s Creep Relaxation Capability

2011 ◽  
Vol 121-126 ◽  
pp. 406-410
Author(s):  
Hong Jiang Chen ◽  
Yue Hai Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mathematical Models ◽  
System Failure ◽  
Test Results ◽  
The Finite Element Method ◽  
System Failures ◽  
Important Trend ◽  
Important Form ◽  
Element Method

Creep relaxation is an important form of system failure, how to understand and analyze the effect of creep relaxation, to solve system failures and improve economic efficiency are of great significance. The paper describe researches of creep relaxation , mathematical models and theories at home and abroad in detail, and introduce the finite element method applied in this field. By comparing with the mathematical models, finite element Methods with test results, improving current mathematical models and utilizing finite element method is an important trend.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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