Infiltration into an embankment reinforced by nonwoven geotextiles

2005 ◽  
Vol 42 (4) ◽  
pp. 1145-1159 ◽  
Author(s):  
T Iryo ◽  
R K Rowe
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Hydraulic Behaviour ◽  
The Finite Element Analysis ◽  
The Stability ◽  
Nonwoven Geotextile ◽  
Analysis Stability ◽  
Embankment Stability

The hydraulic behaviour of permeable geosynthetics within unsaturated embankments subjected to infiltration is examined using the finite element method. The van Genuchten – Mualem model is employed to evaluate unsaturated hydraulic characteristics for both the soil and nonwoven geotextile. Using pore-water pressures obtained from the finite element analysis, stability analyses are conducted for the embankments, and the contribution of the nonwoven geo textile to stability is evaluated with reference to the observed performance of instrumented embankments. A numerical study is also conducted to examine the effect of geotextile configuration on the performance of reinforced embankments subject to infiltration. This study shows that nonwoven geotextiles may retard water flow in situations where the pore pressure is negative, whereas they act as a drainage material in situations where pore pressures are positive. It is also shown that the contribution of the nonwoven geotextile to the stability of the embankment as a drainage material is much less substantial than its role as a reinforcing material.Key words: nonwoven geotextile, drainage, unsaturated, embankment, stability.

scholarly journals Modeling of Size Effects in Bending of Perforated Cosserat Plates

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Roman Kvasov ◽  
Lev Steinberg
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Numerical Study ◽  
The Finite Element Method ◽  
Classical Elasticity ◽  
Element Analysis ◽  
Plate Deformation ◽  
The Finite Element Analysis ◽  
Circular Holes ◽  
Different Shapes

This paper presents the numerical study of Cosserat elastic plate deformation based on the parametric theory of Cosserat plates, recently developed by the authors. The numerical results are obtained using the Finite Element Method used to solve the parametric system of 9 kinematic equations. We discuss the existence and uniqueness of the weak solution and the convergence of the proposed FEM. The Finite Element analysis of clamped Cosserat plates of different shapes under different loads is provided. We present the numerical validation of the proposed FEM by estimating the order of convergence, when comparing the main kinematic variables with an analytical solution. We also consider the numerical analysis of plates with circular holes. We show that the stress concentration factor around the hole is less than the classical value, and smaller holes exhibit less stress concentration as would be expected on the basis of the classical elasticity.

scholarly journals Design and strength analysis of C-hook for load using the finite element method

2020 ◽  
Vol 313 ◽  
pp. 00034
Author(s):  
Pavol Lengvarský ◽  
Martin Mantič ◽  
Róbert Huňady
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Deformation State ◽  
The Finite Element Analysis ◽  
Stress And Deformation ◽  
The Stability

The special type of C-hook is investigated in this paper. The C-hook is designed to carry a special load, where is not possible to use classical hooks or chain slings. The designed hook is consisted of two arms that ensure the stability of the load being carried. The finite element analysis is performed for the control of the stress and deformation state in the whole hook. The fatigue analysis is performed for the check of a lifetime of C-hook.

Analysis of Hydroelectric Unit’s Upper Bracket Based on Test and FEM

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Element Analysis ◽  
Hydroelectric Unit ◽  
The Finite Element Analysis ◽  
Strain Rosette ◽  
The Finite Element Model

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.

Comparison of Buried Pipeline Crossing Assessments Using API RP 1102, Analytical Method and Finite Element Approach

2020 ◽  
Author(s):  
Nikhil Joshi ◽  
Pritha Ghosh ◽  
Jonathan Brewer ◽  
Lawrence Matta
Keyword(s):  
Finite Element ◽  
Analytical Method ◽  
Rapid Assessment ◽  
Buried Pipeline ◽  
The Finite Element Method ◽  
Buried Pipelines ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Element Approach ◽  
Multiple Loading

Abstract API RP 1102 provides a method to calculate stresses in buried pipelines due to surface loads resulting from the encroachment of roads and railroads. The API RP 1102 approach is commonly used in the industry, and widely available software allows for quick and easy implementation. However, the approach has several limitations on when it can be used, one of which is that it is limited to pipelines crossing as near to 90° (perpendicular crossing) as practicable. In no case can the crossing be less than 30° . In this paper, the stresses in the buried pipeline under standard highway vehicular loading calculated using the API RP 1102 method are compared with the results of two other methods; an analytical method that accounts for longitudinal and circumferential through wall bending effects, and the finite element method. The benefit of the alternate analytical method is that it is not subject to the limitations of API RP 1102 on crossing alignment or depth. However, this method is still subject to the limitation that the pipeline is straight and at a uniform depth. The fact that it is analytical in nature allows for rapid assessment of a number of pipes and load configurations. The finite element analysis using a 3D soil box approach offers the greatest flexibility in that pipes with bends or appurtenances can be assessed. However, this approach is time consuming and difficult to apply to multiple loading scenarios. Pipeline crossings between 0° (parallel) and 90° (perpendicular) are evaluated in the assessment reported here, even though these are beyond the scope of API RP 1102. A comparison across the three methods will provide a means to evaluate the level of conservatism, if any, in the API RP 1102 calculation for crossing between 30° and 90° . It also provides a rationale to evaluate whether the API RP 1102 calculation can potentially be extended for 0° (parallel) crossings.

scholarly journals Factor of Safety Reduction Factors for Accounting for Progressive Failure for Earthen Levees with Underlying Thin Layers of Sensitive Soils

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Adam J. Lobbestael ◽  
Adda Athanasopoulos-Zekkos ◽  
Josh Colley
Keyword(s):  
Finite Element ◽  
Strain Softening ◽  
Progressive Failure ◽  
Limit Equilibrium ◽  
Thin Layers ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Limit Equilibrium Methods ◽  
The Stability ◽  
Reduction Factors

The effects of progressive failure on flood embankments with underlying thin layers of soft, sensitive soils are investigated. Finite element analysis allows for investigation of strain-softening effects and progressive failure in soft and sensitive soils. However, limit equilibrium methods for slope stability analysis, widely used in industry, cannot capture these effects and may result in unconservative factors of safety. A parametric analysis was conducted to investigate the effect of thin layers of soft sensitive soils on the stability of flood embankments. A flood embankment was modeled using both the limit equilibrium method and the finite element method. The foundation profile was altered to determine the extent to which varying soft and sensitive soils affected the stability of the embankment, with respect to progressive failure. The results from the two methods were compared to determine reduction factors that can be applied towards factors of safety computed using limit equilibrium methods, in order to capture progressive failure.

Large Deformation Modeling Applied to the Sheet Metal Electromagnetic Forming

2008 ◽  
Author(s):  
C. Dumitras ◽  
I. Cozminca
Keyword(s):  
Finite Element ◽  
Deformation Process ◽  
Electromagnetic Forming ◽  
Stress And Strain ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Strain Fields ◽  
The Finite Element Analysis ◽  
History Of ◽  
Free Bulging

The electromagnetic forming has the advantage of a minimum forming time, but this is a major obstacle in determining the process’s history of the forming workpiece. Both experimental and theoretical known analysis methods for this process give a discret array of data (only for the displacements). One considers it is more adequate to use the finite element method in studying this process. The main advantage of the finite element analysis is given by the fact that it shows the stress and strain fields in a continuous way during the deformation process. Also, it offers a model from which one can predict the final shape of the part and the possible crack zones. One present a compared study of the experimental and the simulated results achieved of the free bulging aluminum specimens by electromagnetic impulses.

Fatigue Strength Study on Radial Bogie Vice Frame Based on Finite Element Analysis

2015 ◽  
Vol 723 ◽  
pp. 96-99
Author(s):  
Xiao Wei Wang ◽  
Mao Xiang Lang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Structural Strength ◽  
Simulation Software ◽  
Experimental Result ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Stability

The vice frame bears and transfers the forces and loads between the bogie and the vehicle body.The strength of the vice frame relates directly to the stability and smoothness of the vehicle. In this study, finite element analysis is utilized first to analyse the structural strength and fatigue life of the vice frame, and the recognize the weak parts of its structure in order to enhance its structural strength in the following design work.The finite element analysis is performed on a simulation software Ansys. Then an experiment is designed to test the fatigue strength of the vice frame. The experimental result indicates that the fatigue strength of the object corresponds to the standards and the finite element analysis has high feasibility in solving this kind of problem.

Testing of a Folded Plate Space Structure

1987 ◽  
Vol 2 (2) ◽  
pp. 115-121
Author(s):  
D. Ho ◽  
P. K. K. Lee ◽  
H. W. Chung ◽  
W. C. Keung
Keyword(s):  
Finite Element ◽  
Space Structure ◽  
Sufficient Accuracy ◽  
Design Stage ◽  
Stage Model ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Actual Structure ◽  
The Finite Element Analysis ◽  
Before And After

A reinforced concrete folded plate space structure of span 28 m and clear height 9·4 m was constructed as a games hall. The structure was analysed using the finite element method. At the design stage, model tests were carried out to check the accuracy of the method of analysis. To assess the behaviour of the actual structure subject to its self-weight, strains and deflections were monitored during construction both before and after removal of formwork. The tests confirmed that results given by the finite element analysis are of sufficient accuracy for the purpose of design, irrespective of the assumptions involved.

The Finite Element Analysis of Asphalt Pavement with Function Layer under Temperature-Load Action

2012 ◽  
Vol 468-471 ◽  
pp. 2413-2416 ◽  
Author(s):  
Chuang Du ◽  
Yan Yan Li ◽  
Rong Guo ◽  
Shi Bin Ma
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Surface Layer ◽  
Asphalt Pavement ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Temperature Load ◽  
Load Action ◽  
Reflection Crack

In order to study the performance of asphalt pavement with function layer under temperature-load coupling action, the thickness of surface layer, the module of surface layer and was analyzed to abtain their influence on the function layer stress using the finite element method. The results clearly indicated that it is very effective to prevent the reflection crack by increasing the thickness of asphalt surface layer and it is not obvious to reduce the reflection crack through enhancing the module of asphalt surface layer.

Finite Element Numerical Analysis of the LGV Frame Based on ANSYS

2012 ◽  
Vol 590 ◽  
pp. 487-491
Author(s):  
Qin Man Fan
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Mechanical Analysis ◽  
Structure Design ◽  
Frame Structure ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Static And Dynamic Characteristics ◽  
The Finite Element Analysis ◽  
Optimizing Design

The frame is the main part of the force matrix of truck vehicle and the stress state is complex and difficult to design. The finite element method is more accurate for the analysis of the static and dynamic characteristics of the frame, which provide guidance for the frame structure design. Establish finite element model of the frame with the application of ANSYS. According to the mechanical analysis of the model, impose reasonable constraints and load, the most typical of the four conditions in the frame is calculated with the finite element analysis, and predicted the weak parts of the frame according to the frame stress-strain cloud, which provided a very important theoretical basis for the improvement of the frame structure of the frame and optimizing design of the frame.

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