Lifting Technique of Composite Bucket Foundation for Offshore Wind Turbines

2020 ◽  
Author(s):  
Hongyan Ding ◽  
Zuntao Feng ◽  
Puyang Zhang ◽  
Conghuan Le
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Large Scale ◽  
Element Model ◽  
Offshore Wind ◽  
Force Transmission ◽  
Element Analysis ◽  
Bucket Foundation ◽  
Transition Section ◽  
Section Structure

Abstract The onshore pre-fabrication technology for composite bucket foundations takes “prefabrication-assembly-lifting” as the core concept. The practice of pre-fabrication of upper and lower structures is prefabricated respectively. In the research of hoisting engineering technology, combined with the structural form and construction requirements of composite bucket foundation, the assembly scheme of the upper prestressed concrete transition section and the lower steel bucket and the hoisting scheme of integral foundation with compartments were designed. The finite element model in the lifting process of composite bucket foundation was established by the large-scale general finite element analysis software ABAQUS. For the optimization analysis of the lifting point arrangement during hoisting process, the number, position and arrangement form of lifting points are simulated and analyzed. The results show that the maximum value of the principal stress of the concrete transition section structure appears in the assembly stage with the lower steel bucket, and the structure checking calculation should be carried out as the most unfavorable lifting condition in construction; the peak point of structural stress is at the junction of girder and secondary beams and inner ring beams of concrete roof, which belongs to the weak position of force transmission. In construction, it should be paid attention to as the key part of monitoring to ensure composite bucket foundation is under reasonable stress and the stability in the lifting process. The research results can provide guidance and reference for the future batch production and standardization production construction for composite bucket foundations.

Finite Element Analysis of Top Flanged Joint System of High Power Level Wind Turbine

2012 ◽  
Vol 591-593 ◽  
pp. 728-732
Author(s):  
Rong Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Rational Design ◽  
Large Scale ◽  
Power Level ◽  
Operating Mode ◽  
Element Model ◽  
Element Analysis ◽  
Joint System

This paper uses non-linear finite element method to structurally analyze top flanged joint system of a MW wind turbine, sets up a finite element model of top flanged joint system by applying finite element analysis software MSC.Marc/Mentat, makes an analysis on the stress distribution of key components of top flanged joint system under ultimate operating mode based on applying appropriate boundary condition and loads, and carries out security examination on top flange and joint bolt. Result shows that key components of the top flanged joint system can satisfy design requirements, and it has a guiding role for rational design and performance improvement of large scale wind turbine flange, which can be used in structural analysis of other flanged joint systems, and has certain practical value in the aspect of engineering.

Structural Analysis and Improvement of Large-Scale Forklift's Wheel Rim

2013 ◽  
Vol 712-715 ◽  
pp. 1080-1083
Author(s):  
Hu Qi Wang ◽  
Hai Zhao He ◽  
Hai Yan Lu ◽  
Rong Xing Huang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Working Conditions ◽  
Large Scale ◽  
Element Model ◽  
Analysis Model ◽  
Element Analysis ◽  
Wheel Rim ◽  
Weak Part ◽  
The Finite Element Analysis

A large-scale forklift's wheel rim appeared cracking phenomenon in the course of use. This article summarized and analyzed force of the forklift's wheel rim according to the typical working conditions of forklift, and calculated the load of various working conditions. It provided the correct boundary conditions for the finite element analysis of the wheel rim [. After the analysis of wheel rim's three typical conditions, found the weak parts of the structure of the rim, and this part was consistent with the feedback part, so it proved correct of the finite element analysis model. Clever was used ribbed-plate and punching groove to strengthen the weak part of wheel rim and the finite element model was used to calculate and check the improved wheel rim again. The results showed that the improved wheel rim stress decreased quite, so the measure was correct.

Finite Element Analysis on Large-Scale Electrical Dust Precipitator Steel Structures

2013 ◽  
Vol 753-755 ◽  
pp. 1196-1200
Author(s):  
Lu Yu Huang ◽  
Yang Gao ◽  
Xia Cao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Optimization Design ◽  
Large Scale ◽  
Steel Structures ◽  
Element Model ◽  
Element Analysis ◽  
Dust Precipitator ◽  
The Finite Element Model

Based on the construction features of the steel structures of a type of electrical dust precipitator, a finite element model is established with large-scale finite element analysis software ANSYS, and the structure stress and displacement of the model under all sorts of loads are analyzed with the frontal solution method. The results indicate that analysis is relatively accurate, the finite element model and the analysis method is appropriate. The result can be further used for optimization design of the electrical precipitator steel structures.

Characterisation of the Shear Stud-Concrete Connection Using Finite Element Analysis

2014 ◽  
Vol 553 ◽  
pp. 570-575
Author(s):  
Daniel John Lowe ◽  
Raj Das ◽  
George Charles Clifton ◽  
Namasivayam Navaranjan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Large Scale ◽  
Numerical Models ◽  
Experimental Testing ◽  
Element Model ◽  
Cement Matrix ◽  
Element Analysis ◽  
Mesoscopic Model ◽  
Concrete Interface

The degradation of the connection between shear studs and concrete is a complicated phenomenon that depends on many factors, including; interfacial properties, concrete crushing and steel yielding. The purpose of this paper is to outline the scope and methodology of the research project being undertaken to characterise the shear stud-concrete interface of a composite beam using finite element analysis. A mesoscopic model will be created for a section of the interface. With the use of a multi-scale approach, the mesoscopic model will be incorporated into a global model. The influence of steel roughness and mechanical properties will be included. Concrete is to be modelled as heterogeneous, comprising discrete regions of aggregate, cement matrix, and an interfacial transition zone (ITZ). The effect of the ITZ will be taken into account using a zero thickness cohesive element. Experimental testing using a push-up rig is to be conducted to verify the numerical models. The ultimate aim is to develop a simplified representation of the shear stud-concrete interface that can be used in a large scale finite element model of a composite member to correctly capture the behaviour of the shear stud-concrete interface in the elastic and inelastic state.

The Nonlinear Finite Element Analysis to Bonded Post-Tensioned Prestressed Concrete Frame Based on Two-Stage Loading Model

2013 ◽  
Vol 671-674 ◽  
pp. 591-595
Author(s):  
Ming Zheng Chen ◽  
Lin Qing Huang ◽  
Xiao Ying Chen ◽  
Li Ping Wang
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Strain Curve ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Arc Length ◽  
Stress Strain Curve ◽  
Element Analysis ◽  
Concrete Frame ◽  
Post Tensioned

According to the loading character of bonded post-tensioned prestressed concrete frame, the static nonlinear finite programme in this paper could be used to analysis the whole loading process to bonded post-tensioned prestressed concrete frame, which is divided into two different stages . From the stress-strain curve of materials and considering the concrete’ tension harding and compression softening, this programme uses the layered finite element model and arc-length method to analyse the bonded post-tensioned prestressed concrete frame, during the course it considers the material nonlinearity and geometric nonlinearity in the stiffness matrix. Through the contrast to experiment , the result of the programme fits well with the experiment. The programme can be used to compute and analyse the bonded post-tensioned prestressed concrete frame.

Influence of Central Buckle on Dynamic Behavior of Long-Span Suspension Bridge with Deck-Truss Composite Stiffening Girder

2013 ◽  
Vol 838-841 ◽  
pp. 1096-1101 ◽  
Author(s):  
Feng Jiang Qin ◽  
Jin Di ◽  
Jie Dai ◽  
Guang Ling Li
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Great Influence ◽  
Suspension Bridge ◽  
Element Model ◽  
Vibration Modes ◽  
Element Analysis ◽  
Long Span ◽  
Main Cable ◽  
Central Buckle

A 3-D finite element model for Yueyang Dongting Lake bridge was established with a large scale general finite element analysis software, and the subspace iteration method was adopted to analyze the natural vibration characteristics of the bridge, meanwhile, the influences of settings different types of central buckles at the mid-span of the main spans between the main cables and girder on the dynamic behaviors of the long-span suspension bridge with deck-truss composite stiffening girder were studied. The results show that compared with only setting short hanger cable at mid-span, the the whole rigidity of suspension bridge is raised and the natural frequencies increase by the setting central buckle, but various types of vibration modes are affected in different extents; among all of these vibration modes, the antisymmetric vibration and Longitudinal floating of stiffening girder are most obviously affected. The stiffness of central buckle has a great influence on the vibration of main cable, while compared with only setting short hanger cable, the vibration of main cable increases 7.32% while setting the rigid central buckle. The conclusions of this paper provide theoretical basis for the using of central buckle in long-span suspension bridge.

Finite Element Model Updating of a Prestressed Concrete Continuous Bridge Based on Dynamic Monitoring

2013 ◽  
Vol 405-408 ◽  
pp. 1645-1650
Author(s):  
Gang Xue ◽  
Wei Yu Bai ◽  
Xian Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Prestressed Concrete ◽  
Large Scale ◽  
Model Updating ◽  
Element Model ◽  
Ambient Vibration ◽  
Dynamic Monitoring ◽  
Modified Technique ◽  
Ambient Vibration Test

The finite element model modified technique based on optimization principle is benefit for the model updating of the large bridge structures. By the ambient vibration test information provided by health monitoring system of huanghe bridge II in baotou , this article adopted corrected parameter based on structural eigenvalue sensitivity analysis to update the bridge dynamic model.The fundamental vibrational frequency of updated finite element model is more closer to the measured result under ambient excitation, which indicates that the optimization algorithm provided by large-scale general software can carry out the model updating effectively.

Finite Element Analysis of Large Diameter Grouted Connections

2007 ◽  
Author(s):  
Lars P. Nielsen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Large Diameter ◽  
Wind Farms ◽  
Element Model ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Joint Research ◽  
Element Analysis

When considering offshore monopile foundations designed for wind turbine support structures, a grouted connection between the monopile and an overlapping transition piece has become the de facto standard. These connections rely on axial loads being carried primarily by the bond between the steel and grout as shear. Given the critical nature of the grouted connection in a system with zero redundancy, the current design verification requirement is that a finite element analysis is performed to ascertain the viability of the connection with respect to combined axial and bending capacity whilst pure axial capacity is handled as a decoupled phenomenon using simple analytical formulas. The present paper addresses the practical modeling aspects of such a finite element model, covering subjects such as constitutive formulations for the grout, mesh density, and steel/grout interaction. The aim of the paper is to discuss different modeling approaches and, to the extent possible, provide basic guidelines for the minimum requirements valid for this type of analysis. This discussion is based on the accumulated experience gained though the independent verification of more than 10 currently operational offshore wind farms that have been certified by DNV, as well as the significant joint research and development with industry captured in the DNV Offshore Standard for Design of Offshore Wind Turbine Structures DNV-OS-J101. Moreover, general observations relating to the basic subjects such as overall geometric extent of the model, inclusion of secondary structures, detail simplification, boundary conditions, load application etc. are presented based on the authors more than 3 year involvement on the subject at DNV.

scholarly journals Analysis of an Approach for Detecting Arc Positions During Vacuum Arc Remelting Based on Magnetic Flux Density Measurements

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Miguel F. Soler ◽  
Kyle E. Niemeyer
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Large Scale ◽  
Element Model ◽  
Vacuum Arc ◽  
Magnetic Flux Density ◽  
Vertical Position ◽  
Element Analysis ◽  
Vacuum Arc Remelting ◽  
Position Sensing

Vacuum arc remelting (VAR) is a melting process for the production of homogeneous ingots, achieved by applying a direct current to create electrical arcs between the input electrode and the resultant ingot. Arc behavior drives quality of the end product, but no methodology is currently used in VAR furnaces at large scale to track arcs in real time. An arc position sensing (APS) technology was recently developed as a methodology to predict arc locations using magnetic field values measured by sensors. This system couples finite element analysis of VAR furnace magnetostatics with direct magnetic field measurements to predict arc locations. However, the published APS approach did not consider the effect of various practical issues that could affect the magnetic field distribution and thus arc location predictions. In this paper, we studied how altering assumptions made in the finite element model affect arc location predictions. These include the vertical position of the sensor relative to the electrode–ingot gap, a varying electrode–ingot gap size, ingot shrinkage, and the use of multiple sensors rather than a single sensor. Among the parameters studied, only vertical distance between arc and sensor locations causes large sources of error and should be considered further when applying an APS system. However, averaging the predicted locations from four evenly spaced sensors helps reduce this error to no more than 16% for a sensor position varying from 0.508 m below and above the electrode–ingot gap height.

Orthodontics Simulation and Finite Element Analysis of Submaxilla Dentition

2012 ◽  
Vol 591-593 ◽  
pp. 712-716
Author(s):  
Dan Liu ◽  
Ai Li Qu ◽  
Chun Xiu Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Force Transmission ◽  
Element Analysis ◽  
Engineering Software ◽  
Elastic Module ◽  
Bodily Movement ◽  
Bone Absorption ◽  
Single Tooth ◽  
Titanium Nickel

Objective The principle and method of the force application is researched in orthodontics field, providing the scale and location of force for clinical orthodontics. Methods Reverse engineering software is used to reconstruct a 3-D mandible finite element model, the MBT bracket and straight archwire on the dentition are modeled on it. Change the elastic module of archwire to simulate four stages of orthodontics and the displacement and stress on dentition and mandible are acquired. Results The finite element results of dentition and mandible under short Ⅱ elastics are obtained, the results show that titanium-nickel archwire may provide major displacement for dentition; O and stainless steel have good force-transmission in teeth. The stress of single tooth and mandible are symmetrical except for the position where loads are applied. Conclusions Under the short II elastics loads, bone absorption don’t appear and the bodily movement of mandible is arose.

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