scholarly journals Stability Analysis of High-Pile and high-pier Considering Initial Pier Deviation

2021 ◽  
Vol 261 ◽  
pp. 02050
Author(s):  
Mei-Liang Zhu ◽  
Li-Qing Zhang ◽  
Ye Ma ◽  
Shun-Kun Jiang
Keyword(s):  
Three Dimensional ◽  
Horizontal Displacement ◽  
Nonlinear Buckling ◽  
Buckling Loads ◽  
Dimensional Finite Element ◽  
Calculation Results ◽  
High Pier ◽  
The Stability ◽  
Three Dimensional Finite Element ◽  
Better Than

Based on the high-pile and high-pier bridge of Qianhuang Expressway, eigenvalue buckling analysis is carried out by establishing three-dimensional finite element models of three different bridge types and high-pier types, and the corresponding structural nonlinear buckling loads under different initial pier deviations are calculated. The calculation results show that the nonlinear buckling loads of three high-pier types are less than elastic buckling loads. The stability of column high-pile and high-pier of continuous bridge is better than that of simple supported bridge, and the stability of plate high-pier is better than that of other two high-piers. In addition, the corresponding buckling load decreases with the increase of the initial horizontal displacement, indicating that the pier top offset of the high-pile and high-pier bridge is not conducive to the stability of the structure.

Structural Stability Evaluation for Lifting Lug Design of Large Marine Engine by Finite Element Analysis

2007 ◽  
Vol 353-358 ◽  
pp. 2855-2859
Author(s):  
W.C. Lee ◽  
Chae Sil Kim ◽  
J.B. Na ◽  
D.H. Lee ◽  
S.Y. Cho ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Procedure ◽  
Steel Structures ◽  
Stability Evaluation ◽  
Element Analysis ◽  
Marine Engines ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element

Since most marine engines are generally very huge and heavy, it is required to keep safety from accidents in dealing them. Several types of lifting lugs have been used to assemble hundred ton–large steel structures and carry the assembled engines. Recently a few crashes have been occurred in carrying engines due to breaking down the lugs. Although the stability evaluation of the lifting lug has therefore been very important for safety, systematic design procedure of the lugs, which includes the structural analysis considering stability, has few reported. This paper describes the three dimensional finite element structural modeling for a lifting lug, the studies for determining the reasonable loading and boundary conditions, and the stability evaluation with the results of structural analyses. It should be very helpful for designing the other types of lifting lugs with safety.

Prediction of the Thermoacoustic Combustion Instabilities in Practical Annular Combustors

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Giovanni Campa ◽  
Sergio Mario Camporeale
Keyword(s):  
Combustion Chamber ◽  
Three Dimensional ◽  
Design Stage ◽  
Combustion Instabilities ◽  
Combustion Chambers ◽  
Stability Maps ◽  
Dimensional Finite Element ◽  
Practical Tool ◽  
The Stability ◽  
Three Dimensional Finite Element

A three-dimensional finite element code is used for the eigenvalue analysis of the thermoacoustic combustion instabilities modeled through the Helmholtz equation. A full annular combustion chamber, equipped with several burners, is examined. Spatial distributions for the heat release intensity and for the time delay are used for the linear flame model. Burners, connecting the plenum and the chamber, are modeled by means of the transfer matrix method. The influence of the parameters characterizing the burners and the flame on the stability levels of each mode of the system is investigated. The obtained results show the influence of the 3D distribution of the flame on the modes. Additionally, the results show what types of modes are most likely to yield humming in an annular combustion chamber. The proposed methodology is intended to be a practical tool for the interpretation of the thermoacoustic phenomenon (in terms of modes, frequencies, and stability maps) both in the design stage and in the check stage of gas turbine combustion chambers.

Optimized Design of Larsen Steel Sheet Pile Supporting Structure Based on Parameter Sensitivity

2014 ◽  
Vol 501-504 ◽  
pp. 770-776 ◽  
Author(s):  
Jin Rong Xie ◽  
Ba Tong Li ◽  
Pi Hui Chen ◽  
Yu Qiong Zhuang
Keyword(s):  
Steel Sheet ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Optimized Design ◽  
Sheet Pile ◽  
Supporting Structure ◽  
Geological Conditions ◽  
Key Factor ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Based on the transformation project of rain and sewage diversion in a city, the optimized design of Larsen steel sheet pile supporting structure in pipe-pit excavation was made. Using three-dimensional finite element method to analyze the retaining characteristics of Larsen steel sheet pile, soil deformation of adjacent transverse brace in the middle position and surface subsidence were regarded as design control indicators; through numerical analysis of the geological conditions, load, pile length, horizontal interval of transverse brace and other factors on the sensitivity of the design control indicators, horizontal displacement of brace was regarded as a key factor in the optimal design, and accordingly, related optimized program was proposed. The implementation results show that the optimized scheme can improve the efficiency of construction, protect the safety of construction, and provide a reference for the design and construction of similar projects.

Assessment of Free Standing Body in Dry and Submerged Condition and Under Seismic Loading

2019 ◽  
Author(s):  
Beniamino Rovagnati ◽  
Phuong H. Hoang
Keyword(s):  
Three Dimensional ◽  
Nuclear Industry ◽  
Spent Fuel ◽  
Free Standing ◽  
Transient Model ◽  
Dimensional Finite Element ◽  
Rocking Motion ◽  
Free Body ◽  
The Stability ◽  
Three Dimensional Finite Element

Abstract A free standing, slender body may experience rocking motion followed by overturning when it is subject to strong seismic motions. When the free body is submerged in water, it will also be subject to lateral forces acting along the side of the free body as a result of water sloshing. This highly non-linear situation is of particular interest to engineers in the nuclear industry in need to assess the stability of transfer casks containing spent fuel and submerged in a confined pit or pool. In this work, a three-dimensional finite element dynamic transient model of a free standing cask is developed and analyzed using ANSYS. Both dry and submerged conditions are considered. Cask to floor friction, buoyancy force, and sloshing are accounted for in the assessment. The model is validated against well-accepted contributions on sloshing and rocking provided by G.W. Housner.

The Stress and Displacement Analysis of the Cut-Off Wall for the Deep Overburden Dam

2011 ◽  
Vol 393-395 ◽  
pp. 463-466
Author(s):  
Bo Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Element Analysis ◽  
Nonlinear Constitutive Model ◽  
Dimensional Finite Element ◽  
Clay Core ◽  
Dam Stability ◽  
Three Dimensional Finite Element

The Duncan-Chang nonlinear constitutive model is used to carry out a three-dimensional finite element analysis of Xia Ban Di deep overburden dam with clay core. The regularities of the horizontal displacement, vertical stress and stress level for the cut-off wall are studied in this paper, and the paper provided reference for the dam stability and anti-seepage treatment of the cut-off wall with deep overburden.

Thermoelectric Analysis for a Three-Dimensional Power Generator in Helical

2014 ◽  
Vol 617 ◽  
pp. 260-264
Author(s):  
Xiang Ning Meng ◽  
Takeyuki Fujisaka ◽  
Ryosuke O. Suzuki
Keyword(s):  
Output Power ◽  
Three Dimensional ◽  
Fe Model ◽  
Power Generator ◽  
Straight Line ◽  
Dimensional Finite Element ◽  
Helical Geometry ◽  
Three Dimensional Finite Element ◽  
Volume Method ◽  
Better Than

Thermoelectric (TE) phenomenon of a helical generator is numerically analyzed by using the finite-volume method in combination with a three-dimensional finite-element (FE) model. The distributions of temperature and current density are significantly influenced by the generator dimension. The output power of helical generator is also affected by the geometric parameter, such as the helical pitch. The output power and conversion efficiency of helical generator are better than those of straight generator where all the TE elements aligned in a straight line. The helical geometry has a satisfactory potential to be a good TE generator.

Stability of Vertically Bent Pipelines Buried in Sand

2004 ◽  
Vol 126 (3) ◽  
pp. 382-390 ◽  
Author(s):  
Sahel N. Abduljauwad ◽  
Hamdan N. Al-Ghamedy ◽  
Junaid A. Siddiqui ◽  
Ibrahim M. Asi ◽  
Naser A. Al-Shayea
Keyword(s):  
Internal Pressure ◽  
Three Dimensional ◽  
Computer Software ◽  
Specific Weight ◽  
Bend Angle ◽  
Element Analysis ◽  
Minimum Cover ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element

This paper discusses the stability of underground pipelines with preformed vertical bends buried in sandy soil. More specifically, the minimum cover height required to prevent the pipe from bowing under the action of forces due to temperature change and internal pressure is estimated. The variables considered include the pipe and soil materials, diameter, thickness, overburden height, bend radius, bend angle, internal pressure, fluid specific weight, and temperature variation. A comprehensive three-dimensional finite element analysis is carried out. The results are extracted from the output obtained. These results are put in a database which is used to develop general regression models to determine the relationships among the different variables. Different buckling modes are also considered. All of these results and models are entered into a computer software program for ready access.

Closure of a Nuclear Waste Repository Deeply Imbedded in a Stratified Salt Bed

1994 ◽  
Vol 116 (4) ◽  
pp. 567-573 ◽  
Author(s):  
Wei Xu ◽  
Joseph Genin
Keyword(s):  
Triaxial Compression ◽  
Three Dimensional ◽  
Element Model ◽  
Nuclear Waste Repository ◽  
Relaxation Functions ◽  
Dimensional Finite Element ◽  
Set Up ◽  
The Stability ◽  
Three Dimensional Finite Element

The Waste Isolation Pilot Plant (WIPP) is a repository vault, mined deep into a salt strata. It eventually closes in on itself, encapsulating its contents. At room temperature salt may be regarded as a linear, isotropic, viscoelastic material. In this study, using triaxial compression test results on salt, we determine the relaxation functions and set up the boundary value problem for the encapsulation mechanism of a salt vault. Closure of the repository as a function of time is determined using a three-dimensional finite element model. The Tresca failure criterion is used to predict the stability of the repository. Finally, the study is validated by comparing our results to in-situ measured data.

scholarly journals Model Test Study on the Influence of Ground Surcharges on the Deformation of Shield Tunnels

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1565
Author(s):  
Gang Wei ◽  
Shuming Zhang ◽  
Pengfei Xiang
Keyword(s):  
Model Test ◽  
Three Dimensional ◽  
Theoretical Method ◽  
Shield Tunnel ◽  
Burial Depth ◽  
Scaled Model ◽  
Test Study ◽  
Dimensional Finite Element ◽  
Calculation Results ◽  
Three Dimensional Finite Element

Aiming at studying the harm caused by sudden ground loadings on existing shield tunnels, a indoor scaled model test with a geometric similarity ratio of 1:15.5 was adopted. Considering the influencing factors such as ground loading, burial depth of the shield tunnel, loading position and soil properties, tunnel convergence deformation, tunnel settlement and deep settlement of soil caused by sudden ground loadings are studied. A three-dimensional finite element simulation is carried out using the Midas software, and deep settlement of soil is calculated by a theoretical method. The purpose of this model test is to further understand the influence of ground surcharges on shield tunnel deformation. The results show that the greater the ground surcharge, the greater the settlement and vertical convergence deformation of the shield tunnel; The further away from the ground surcharge, the smaller the settlement, vertical convergence deformation and lateral convergence deformation of the tunnel. When the pile load size is constant, the greater the burial depth of the tunnel, the smaller the vertical convergence deformation and settlement of the tunnel; the maximum value of deep settlement of the soil always remains at the closest point to the ground surcharge; compared with the use of dry sand, the vertical convergence deformation and settlement of the tunnel are significantly reduced when using wet sand. Both the theoretical calculation results and the numerical simulation results are in good agreement with the indoor model test results.

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