Study on Stability of High Embankments under Complicated Stress Conditions

Three-dimensional finite element analysis should be used in stability analysis of slope because it can overcome the short advantages of two-dimensional finite element and can simulate the complex topographic and geological conditions. Based on the large-scale triaxial shear test, the modified Duncan-Chang model is established. Based on strength reduction elasto-plastic finite element, stability of high fill embankment was studied with three-dimensional finite element method considering the complex terrain conditions. Study results suggest that plastic strain and displacement mutant of slip surface node can be a sign of slope instability as a whole. At the same time calculation of three-dimensional finite element also does not converge. Therefore, it can be slope instability criterion calculate whether the finite element static analysis converges or not. On the other hand, stability safety factor of high fill embankment under three-dimensional conditions is larger than that of two-dimensional conditions, which shows that boundary conditions of high fill embankment enhance its stability.

Study on Stability of High Embankment with Strong Weathering Filling under Complicated Stress Conditions

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.97-98.78 ◽

2011 ◽

Vol 97-98 ◽

pp. 78-84

Author(s):

Sheng Chuan Liu

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Three Dimensional ◽

Strength Reduction ◽

Slope Instability ◽

Instability Criterion ◽

Two Dimensional ◽

Element Analysis ◽

Strength reduction elasto-plastic finite element analysis defines the reduction factor when slope has been destroyed as the slope stability factor of safety, which combines with strength reduction technique, the limit equilibrium theory and the principle of elastic-plastic finite element. Three-dimensional finite element analysis should be used in stability analysis of slope because it can overcome the short advantages of two-dimensional finite element and can simulate the complex topographic and geological conditions. Based on the large-scale triaxial shear test, the modified Duncan-Chang model is established. Based on strength reduction elasto-plastic finite element, stability of high fill embankment was studied with three-dimensional finite element method considering the complex terrain conditions. Study results suggest that plastic strain and displacement mutant of slip surface node can be a sign of slope instability as a whole. At the same time calculation of three-dimensional finite element also does not converge. Therefore, it can be slope instability criterion calculate whether the finite element static analysis converges or not. On the other hand, stability safety factor of high fill embankment under three-dimensional conditions is larger than that of two-dimensional conditions, which shows that boundary conditions of high fill embankment enhance its stability.

Inclusion of Local Shell Behavior of Tubes Into a Two-Dimensional Beam Approximation of Deformation in Nuclear Fuel Channels

Computational Mechanics: Developments and Applications ◽

10.1115/pvp2002-1287 ◽

2002 ◽

Author(s):

S. Khajehpour ◽

R. G. Sauve´ ◽

N. Badie

Keyword(s):

Finite Element ◽

Contact Stiffness ◽

Three Dimensional ◽

Local Deformation ◽

Beam Model ◽

Two Dimensional ◽

Dimensional Modeling ◽

Nonlinear Force ◽

A method has been developed to incorporate the local three-dimensional shell behavior of two concentric tubes in the two-dimensional beam modeling of the problem. The two dimensional modeling of fuel channels in CANDU pressurized heavy water nuclear reactors is used in lieu of a more accurate three dimensional finite element approach in order to reduce the on-line simulation time which greatly affects the SLAR (Spacer Location And Repositioning) maintenance operation cost during outage. However, effort must be made to include the three-dimensional shell behavior of these channels into the two-dimensional modeling. In recent studies a nonlinear force-dependent model for contact stiffness between the calandria tube and pressure tube has been developed. However, local deformation of calandria the tube at spacer locations due to in-reactor creep leads to settling of the spacer into the calandria tube that consequently reduces the gap between the two tubes. In this work, the effect of local deformation (elastic and creep) of calandria tubes on modeling of contact at spacer locations is assessed using a three dimensional finite element code. The result is incorporated into a two-dimensional beam model of the problem as a reduction in size of the spacers that separate the two tubes. It is shown that the proposed method increases the accuracy of prediction of contact time and the spacer. In general, the method described in this paper suggests a way to incorporate local shell deformation into beam models of slender shell structure.

Preliminary Ship Design Using One and Two-Dimensional Models

Marine Technology and SNAME News ◽

10.5957/mt1.1999.36.2.102 ◽

1999 ◽

Vol 36 (02) ◽

pp. 102-112

Author(s):

Michael D. A. Mackney ◽

Carl T. F. Ross

Keyword(s):

Finite Element ◽

Dimensional Analysis ◽

Three Dimensional ◽

Two Dimensional ◽

One Dimensional ◽

Dimensional Models ◽

Support Conditions ◽

The One ◽

Computational studies of hull-superstructure interaction were carried out using one-, two-and three-dimensional finite element analyses. Simplification of the original three-dimensional cases to one- and two-dimensional ones was undertaken to reduce the data preparation and computer solution times in an extensive parametric study. Both the one- and two-dimensional models were evaluated from numerical and experimental studies of the three-dimensional arrangements of hull and superstructure. One-dimensional analysis used a simple beam finite element with appropriately changed sections properties at stations where superstructures existed. Two-dimensional analysis used a four node, first order quadrilateral, isoparametric plane elasticity finite element, with a corresponding increase in the grid domain where the superstructure existed. Changes in the thickness property reflected deck stiffness. This model was essentially a multi-flanged beam with the shear webs representing the hull and superstructure sides, and the flanges representing the decks One-dimensional models consistently and uniformly underestimated the three-dimensional behaviour, but were fast to create and run. Two-dimensional models were also consistent in their assessment, and considerably closer in predicting the actual behaviours. These models took longer to create than the one-dimensional, but ran in very much less time than the refined three-dimensional finite element models Parametric insights were accomplished quickly and effectively with the simplest model and processor, but two-dimensional analyses achieved closer absolute measure of the displacement behaviours. Although only static analysis with simple loading and support conditions were presented, it is believed that similar benefits would be found for other loadings and support conditions. Other engineering components and structures may benefit from similarly judged simplification using one- and two-dimensional models to reduce the time and cost of preliminary design.

Two-dimensional and three-dimensional finite element modelling of mantle processes beneath central South Island, New Zealand

Geophysical Journal International ◽

10.1111/j.1365-246x.2006.02930.x ◽

2006 ◽

Vol 165 (3) ◽

pp. 1003-1028 ◽

Cited By ~ 16

Author(s):

Zhen Liu ◽

Peter Bird

Keyword(s):

Finite Element ◽

New Zealand ◽

Finite Element Modelling ◽

Three Dimensional ◽

Two Dimensional ◽

Element Modelling ◽

Mantle Processes ◽

Three Dimensional Finite Element ◽

Central South

Three-Dimensional Response of the Supported-Deep Excavation System: Case Study of a Large Scale Underground Metro Station

Geosciences ◽

10.3390/geosciences10020076 ◽

2020 ◽

Vol 10 (2) ◽

pp. 76

Author(s):

Ashraf Hefny ◽

Mohamed Ezzat Al-Atroush ◽

Mai Abualkhair ◽

Mariam Juma Alnuaimi

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Large Scale ◽

Three Dimensional ◽

Element Model ◽

Two Dimensional ◽

Deep Excavation ◽

Metro Station ◽

The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation problems, especially for cases with a relatively high aspect ratio in plan dimensions. In this research, a two-dimensional finite element model was established to simulate the behavior of the supporting system of a large-scale deep excavation utilized in the construction of an underground metro station Rod El Farrag project (Egypt). The essential geotechnical engineering properties of soil layers were calculated using results of in-situ and laboratory tests and empirical correlations with SPT-N values. On the other hand, a three-dimensional finite element model was established with the same parameters adopted in the two-dimensional model. Sufficient sensitivity numerical analyses were performed to make the three-dimensional finite element model economically feasible. Results of the two-dimensional model were compared with those obtained from the field measurements and the three-dimensional numerical model. The comparison results showed that 3D high stiffening at the primary walls’ corners and also at the locations of cross walls has a significant effect on both the lateral wall deformations and the neighboring soil vertical settlement.

Mechanics of Die-less Asymmetric Rolling for Fabrication of Compound Curved Plates

Journal of Manufacturing Science and Engineering ◽

10.1115/1.1616950 ◽

2003 ◽

Vol 125 (4) ◽

pp. 787-793 ◽

Cited By ~ 2

Author(s):

Jong-Gye Shin ◽

Yang-Ryul Choi ◽

Hyunjune Yim

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Three Dimensional ◽

Element Model ◽

Two Dimensional ◽

Asymmetric Rolling ◽

Three Dimensional Finite Element ◽

First Time ◽

Curvature Control

The mechanics of die-less asymmetric rolling has been investigated in depth, for the first time, using a two-dimensional analytical model and a three-dimensional finite element model. In doing so, the physical understanding of mechanics underlying die-less asymmetric rolling has greatly been enhanced. Moreover, the asymmetry in roller radii was found to be the most effective parameter for curvature control, in the considered ranges of various parameters.

THREE DIMENSIONAL FINITE ELEMENT SIMULATION OF THE FRETTING WEAR PROBLEMS

International Journal of Modern Physics B ◽

10.1142/s0217979206040544 ◽

2006 ◽

Vol 20 (25n27) ◽

pp. 3890-3895 ◽

Cited By ~ 2

Author(s):

CHOON YEOL LEE ◽

JOON WOO BAE ◽

BYUNG SUN CHOI ◽

YOUNG SUCK CHAI

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Three Dimensional ◽

Fretting Wear ◽

Symmetric Model ◽

Two Dimensional ◽

Element Analysis ◽

Inconel 690 ◽

The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element analysis was used to investigate fretting wear on the secondary side of the steam generator, which arises from flow-induced vibrations (FIV) between the U-tubes and supports or foreign objects. Two-dimensional and three-dimensional finite element analyses were adopted to investigate the fretting wear problems. The purpose of the two-dimensional analysis, which simulated the contact between a punch and a plate, was to demonstrate the validity of using finite element analysis to analyze fretting wear problems. This was achieved by controlling the value of the wear constant and the number of cycles. The two-dimensional solutions obtained from this study were in good agreement with previous results reported by Strömberg. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate tubes contacting at right angles. The results of the analyses showed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.