Large-deformation finite element analysis of the interaction between concrete cut-off walls and high-plasticity clay in an earth core dam

2017 ◽  
Vol 34 (4) ◽  
pp. 1126-1148 ◽  
Author(s):  
Xiang Yu ◽  
Degao Zou ◽  
Xianjing Kong ◽  
Long Yu
Keyword(s):  
Finite Element ◽  
Large Deformation ◽  
Small Strain ◽  
Fe Analysis ◽  
Hyperbolic Model ◽  
High Plasticity ◽  
Fe Method ◽  
Content Type ◽  
Earth Core ◽  
High Plasticity Clay

Purpose A large, uneven settlement that is unfavourable to dam safety can occur between a concrete cut-off wall and the high-plasticity clay of earth core dam built on alluviums. This issue has been often studied using the small-strain finite element (FE) method in previous research. This paper aims to research the interaction behaviour between a concrete cut-off wall and high-plasticity clay using large-deformation FE analyses. Design/methodology/approach The re-meshing and interpolation technique with a small-strain (RITSS) method was performed using an independently developed program and adopted for large-deformation FE analyses, and a suitable element size for the high-plasticity clay region was suggested. The layered construction process of an earth core dam built on thick alluviums was simulated using the RITSS method incorporating a hyperbolic model for soil. Findings The RITSS method is an effective technique for simulating the soil–structure interaction during dam construction. The RITSS analysis predicted a higher maximum principle stress of the concrete cut-off wall and higher stress levels in the high-plasticity clay region than small-strain FE analysis. Originality/value A practical method for large-deformation FE analysis was advised and was used for the first time to study the interaction between a concrete cut-off wall and high-plasticity clay in dam engineering. Large deformation in the high-plasticity clay was handled using the RITSS method. Moreover, the penetration process of the concrete cut-off wall into the high-plasticity clay was captured using a favourable element shape and mesh density.

Analysis of Three Dimensional Nonlinear Coupled Finite Element Based on some Concrete Rock-Fill Dam

2014 ◽  
Vol 998-999 ◽  
pp. 522-525
Author(s):  
Juan Juan Jin ◽  
Min He ◽  
Peng Liu
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
High Plasticity ◽  
Element Analysis ◽  
Rock Fill ◽  
Arching Effect ◽  
Earth Core ◽  
Gravel Soil ◽  
High Plasticity Clay ◽  
The Difference

As the future highest dam in the world, Shuang Jiang Kou rock-fill dam was the water retaining structure of homonymous hydropower station, a controlling engineering on Da Du River hydropower development, which is under design now. This dam is a central earth core dam with a height of 312 meters. A type of gravel soil stiffer than clay, which is made by artificial compounding of clay and gravel, is introduced to reduce the difference in displacement of earth core and rock filled shell zone. Because of the introduced less flexible central core, a more remarkable arching effect of the abutment on earth core might occur simultaneously. A three dimensional coupled nonlinear finite element analysis is carried out to study the three dimensional arching effect of Shuang Jiang Kou rock-fill dam. Computation results show that the arching effect is much notable. Then an innovation is proposed in design, in which a contact high-plasticity clay layer is introduced. It is verified that this innovation is effective and necessary.

A Coupled Finite Element and Meshless Local Petrov-Galerkin Method for Large Deformation Problems

2010 ◽  
Vol 97-101 ◽  
pp. 3777-3780 ◽  
Author(s):  
Di Li ◽  
Zhi Yong Lu ◽  
Wen Qian Kang
Keyword(s):  
Finite Element ◽  
Large Deformation ◽  
Computational Efficiency ◽  
Present Method ◽  
Fe Analysis ◽  
Interface Element ◽  
Fe Method ◽  
Mlpg Method ◽  
Coupling Algorithm ◽  
Large Deformation Problems

Based on the interface element method, a coupling algorithm for the large deformation problems has been proposed, which converts the FE analysis into the MLPG computation to preserve the accuracy in the region where meshes have been severely distorted. Numerical example shows that the present method exploits the respective advantages of both the FE method whose computational efficiency is high and the MLPG method which is suitable for large deformation.

Numerical Simulation of Drag Anchor Installation by a Large Deformation Finite Element Technique

2014 ◽  
Author(s):  
Yanbing Zhao ◽  
Haixiao Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Large Deformation ◽  
Fe Simulation ◽  
Fe Analysis ◽  
Movement Direction ◽  
Pullout Capacity ◽  
Fe Method ◽  
Element Analysis ◽  
Element Technique

Previously published finite element analysis of drag anchors only involved the pullout capacity of the anchor. There are no finite element (FE) simulations of the installation of drag anchors probably because of two restrictions. First, during the anchor installation, the installation line is needed, which is difficult to be simulated in the FE analysis. Second, the anchor installation that involves large deformation of surrounding soils can not be solved using the classical FE method. In the present work, the installation line is constructed by connecting cylindrical units with each other using connector elements. Then it is introduced into the installation of drag anchors, which is simulated by a large deformation finite element analysis using the coupled Eulerian-Lagrangian (CEL) technique. By comparing with theoretical solutions, including the tension and profile of the installation line embedded in soils, and the movement direction, drag force, drag angle and trajectory of the anchor, the FE simulation of the drag anchor installation is well verified. The present study also demonstrates that the CEL technique is effective for simulating the anchor-line-soil interactional problems.

Application of the particle finite element method for large deformation consolidation analysis

2019 ◽  
Vol 36 (9) ◽  
pp. 3138-3163 ◽  
Author(s):  
Wei-Hai Yuan ◽  
Wei Zhang ◽  
Beibing Dai ◽  
Yuan Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deformation ◽  
Excess Pore Pressure ◽  
Triangular Element ◽  
Particle Finite Element Method ◽  
Content Type ◽  
Modified Cam Clay ◽  
Large Deformation Problems ◽  
Element Method

Purpose Large deformation problems are frequently encountered in various fields of geotechnical engineering. The particle finite element method (PFEM) has been proven to be a promising method to solve large deformation problems. This study aims to develop a computational framework for modelling the hydro-mechanical coupled porous media at large deformation based on the PFEM. Design/methodology/approach The PFEM is extended by adopting the linear and quadratic triangular elements for pore water pressure and displacements. A six-node triangular element is used for modelling two-dimensional problems instead of the low-order three-node triangular element. Thus, the numerical instability induced by volumetric locking is avoided. The Modified Cam Clay (MCC) model is used to describe the elasto-plastic soil behaviour. Findings The proposed approach is used for analysing several consolidation problems. The numerical results have demonstrated that large deformation consolidation problems with the proposed approach can be accomplished without numerical difficulties and loss of accuracy. The coupled PFEM provides a stable and robust numerical tool in solving large deformation consolidation problems. It is demonstrated that the proposed approach is intrinsically stable. Originality/value The PFEM is extended to consider large deformation-coupled hydro-mechanical problem. PFEM is enhanced by using a six-node quadratic triangular element for displacement and this is coupled with a four-node quadrilateral element for modelling excess pore pressure.

Homogenization of multi-turn coil with elliptic cross-section using complex permeability

2019 ◽  
Vol 38 (3) ◽  
pp. 999-1008 ◽  
Author(s):  
Shogo Fujita ◽  
Hajime Igarashi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Cross Section ◽  
Fe Analysis ◽  
Complex Permeability ◽  
Elliptic Cross Section ◽  
Content Type ◽  
Elliptic Cross ◽  
Good Agreement

Purpose The tensor complex permeability of a multi-turn coil with elliptic cross-section is analytically expressed. In field analysis, a multi-turn coil can be modeled by the uniform material that has the present tensor complex permeability. It is shown that the frequency characteristic of the present tensor complex permeability is in good agreement with that evaluated by finite element method applied to a unit cell of the multi-turn coil region. Design/methodology/approach The authors introduce a new method to evaluate the complex permeability of a multi-turn rectangular coil. To obtain the complex permeability of a rectangular coil in a closed form, it is approximated as an elliptic coil. Because the rectangular coil has different complex permeabilities in the vertical and horizontal directions, the complex permeability have to be defined in a tensor form. It suffices to discretize the coil region into rather coarse finite elements without considering the skin depth in contrast to the conventional finite element method. Findings The proposed method is shown to give the impedance of multi-turn coils which is in good agreement with results obtained by the conventional finite element (FE) analysis. By extending the proposed approach, the authors can easily perform 3D FE analysis without difficulty in discretization of the coil region with fairly fine finite elements. Moreover, they found that the approximation of rectangular coils as the elliptic coils is valid for analysis of quasi-static fields using this homogenization method. Originality/value The novelty of this study is in the approximation of the rectangular coils with elliptic coils, and the complex permeability for them is formulated here in a closed form. The proposed formula includes that for the round coils. Using the present method, the authors analyze the rectangular coils without fine discretization.

An adaptive nonlinear finite element analysis of minimal surface problem based on element energy projection technique

2020 ◽  
Vol 37 (8) ◽  
pp. 2847-2869
Author(s):  
Kaifeng Jiang ◽  
Si Yuan ◽  
Qinyan Xing
Keyword(s):  
Finite Element ◽  
Minimal Surface ◽  
Error Control ◽  
Nonlinear Problems ◽  
Fe Analysis ◽  
Nonlinear Finite Element ◽  
Maximum Norm ◽  
Element Analysis ◽  
Content Type ◽  
Element Energy Projection

Purpose This paper aims to propose a new adaptive strategy for two-dimensional (2D) nonlinear finite element (FE) analysis of the minimal surface problem (MSP) based on the element energy projection (EEP) technique. Design/methodology/approach By linearizing nonlinear problems into a series of linear problems via the Newton method, the EEP technique, which is an effective and reliable point-wise super-convergent displacement recovery strategy for linear FE analysis, can be directly incorporated into the solution procedure. Accordingly, a posteriori error estimate in maximum norm was established and an adaptive 2D nonlinear FE strategy of h-version mesh refinement was developed. Findings Three classical known surfaces, including a singularity problem, were analysed. Moreover, an example whose analytic solution is unavailable was considered and a comparison was made between present results and those computed by the MATLAB PDE toolbox. The results show that the adaptively-generated meshes reflect the difficulties inherent in the problems and the proposed adaptive analysis can produce FE solutions satisfying the user-preset error tolerance in maximum norm with a fair adaptive convergence rate. Originality/value The EEP technique for linear FE analysis was extended to the nonlinear procedure of MSP and can be expected to apply to other 2D nonlinear problems. The employment of the maximum norm makes point-wisely error control on the sought surfaces possible and makes the proposed method distinguished from other adaptive FE analyses.

A comprehensive nonlinear finite element modelling and parametric analysis of reinforced concrete beams

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pandimani Pandimani ◽  
Markandeya Raju Ponnada ◽  
Yesuratnam Geddada
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Ultimate Load ◽  
Fe Analysis ◽  
Fe Model ◽  
Rc Beams ◽  
Content Type ◽  
Bond Slip ◽  
Slip Mechanism

Purpose This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static load using the robust and reliable general-purpose finite element (FE) software ANSYS. A parametric study is carried out to analyse the flexural and ductility behaviour of RC beams under various influencing parameters. Design/methodology/approach To develop and validate the numerical FE models, a total of four experimentally tested simply supported RC beams are taken from the available literature and two beams are selected from each author. The concrete, steel reinforcements, bond-slip mechanism, loading and supporting plates are modelled using SOLID65, LINK180, COMBIN39 and SOLID185 elements, respectively. The validated models are then used to conduct parametric FE analysis to investigate the effect of concrete compressive strength, percentage of tensile reinforcement, compression reinforcement ratio, transverse shear reinforcement, bond-slip mechanism, concrete compressive stress-strain constitutive models, beam symmetry and varying overall depth of beam on the ultimate load-carrying capacity and ductility behaviour of RC beams. Findings The developed three-dimensional FE models can able to capture the load and midspan deflections at critical points, the accurate yield point of steel reinforcements, the formation of initial and progressive concrete crack patterns and the complete load-deflection curves of RC beams up to ultimate failure. From the numerical results, it can be concluded that the FE model considering the bond-slip effect with Thorenfeldt’s concrete compressive stress-strain model exhibits a better correlation with the experimental data. Originality/value The ultimate load and deflection results of validated FE models show a maximum deviation of less than 10% and 15%, respectively, as compared to the experimental results. The developed model is also capable of capturing concrete failure modes accurately. Overall, the FE analysis results were found quite acceptable and compared well with the experimental data at all loading stages. It is suggested that the proposed FE model is a practical and reliable tool for analyzing the flexural behaviour of RC members and can be used for performing parametric studies.

Finite-element modeling of partially prestressed concrete beams with unbonded tendon under monotonic loadings

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pandimani ◽  
Markandeya Raju Ponnada ◽  
Yesuratnam Geddada
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Nonlinear Response ◽  
Concrete Beams ◽  
Fe Analysis ◽  
Material Behavior ◽  
Fe Model ◽  
Ansys Software ◽  
Content Type ◽  
Prestressing Tendon

Purpose The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The finite-element (FE) simulation of such beams using numerical software is very scarce in the literature and therefore this study is taken to demonstrate the modeling aspects of unbonded partially prestressed concrete (UPPSC) beams. This study aims to present the three-dimensional (3-D) nonlinear FE simulations of UPPSC beams subjected to monotonic static loadings using the numerical analysis package ANSYS. Design/methodology/approach The sensitivity study is carried out with three different mesh densities to obtain the optimum elements that reflect on the load–deflection behavior of numerical models, and the model with optimum element density is used further to model all the UPPSC beams in this study. Three half-symmetry FE model is constructed in ANSYS parametric design language domain with proper boundary conditions at the symmetry plane and support to achieve the same response as that of the full-scale experimental beam available in the literature. The linear and nonlinear material behavior of prestressing tendon and conventional steel reinforcements, concrete and anchorage and loading plates are modeled using link180, solid65 and solid185 elements, respectively. The Newton–Raphson iteration method is used to solve the nonlinear solution of the FE models. Findings The evolution of concrete cracking at critical loadings, yielding of nonprestressed steel reinforcements, stress increment in the prestressing tendon, stresses in concrete elements and the complete load–deflection behavior of the UPPSC beams are well predicted by the proposed FE model. The maximum discrepancy of ultimate moments and deflections of the validated FE models exhibit 13% and −5%, respectively, in comparison with the experimental results. Practical implications The FE analysis of UPPSC beams is done using ANSYS software, which is a versatile tool in contrast to the experimental testing to study the stress increments in the unbonded tendons and assess the complete nonlinear response of partially prestressed concrete beams. The validated numerical model and the techniques presented in this study can be readily used to explore the parametric analysis of UPPSC beams. Originality/value The developed model is capable of predicting the strength and nonlinear behavior of UPPSC beams with reasonable accuracy. The load–deflection plot captured by the FE model is corroborated with the experimental data existing in the literature and the FE results exhibit good agreement against the experimentally tested beams, which expresses the practicability of using FE analysis for the nonlinear response of UPPSC beams using ANSYS software.

scholarly journals Application of Linear Viscoelastic Properties in Semianalytical Finite Element Method with Recursive Time Integration to Analyze Asphalt Pavement Structure

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Pengfei Liu ◽  
Qinyan Xing ◽  
Dawei Wang ◽  
Markus Oeser
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Asphalt Pavement ◽  
Time Integration ◽  
Asphalt Mixture ◽  
Small Strain ◽  
Asphalt Pavements ◽  
Computational Time ◽  
Fe Method ◽  
Element Method

Traditionally, asphalt pavements are considered as linear elastic materials in finite element (FE) method to save computational time for engineering design. However, asphalt mixture exhibits linear viscoelasticity at small strain and low temperature. Therefore, the results derived from the elastic analysis will inevitably lead to discrepancies from reality. Currently, several FE programs have already adopted viscoelasticity, but the high hardware demands and long execution times render them suitable primarily for research purposes. Semianalytical finite element method (SAFEM) was proposed to solve the abovementioned problem. The SAFEM is a three-dimensional FE algorithm that only requires a two-dimensional mesh by incorporating the Fourier series in the third dimension, which can significantly reduce the computational time. This paper describes the development of SAFEM to capture the viscoelastic property of asphalt pavements by using a recursive formulation. The formulation is verified by comparison with the commercial FE software ABAQUS. An application example is presented for simulations of creep deformation of the asphalt pavement. The investigation shows that the SAFEM is an efficient tool for pavement engineers to fast and reliably predict asphalt pavement responses; furthermore, the SAFEM provides a flexible, robust platform for the future development in the numerical simulation of asphalt pavements.

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