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Element-Based Methods for the Solution of Engineering Problems
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Element-Based Methods for the Solution of Engineering Problems

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Civil Engineering".

Deadline for manuscript submissions: closed (20 December 2021) | Viewed by 31680

Special Issue Editors

Dr. Julio Marti

E-Mail Website
Guest Editor
Facultat de Ciències, Tecnologia i Enginyeries (FCTE), Universitat de Vic - Universitat Central de Catalunya, 08500 Vic, Spain
Interests: fluid-structure interaction; multiphase flows; coupled problems; free-surface flows; mesh-moving methods
Special Issues, Collections and Topics in MDPI journals
Dr. Pavel Ryzhakov

E-Mail Website
Guest Editor
Department of Environmental and Civil Engineering (DECA), Universitat Politècnica de Catalunya, 08034 Barcelona, Spain
Interests: FEM; CFD; fluid-structure interaction; multiphase flow; fuel cells
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The finite element method (FEM) is one of the most used numerical methods thanks to its robustness and the fact that it has been well-developed to date. With advances in computational sciences and the development of modern computer architectures, the FEM has been successfully applied to complex problems in several fields, such as aerospace, civil, mechanical, and biomedical engineering. Often, this has required developing additional “ingredients” to ensure the proper functionality of FEM given the specific features of the problem at hand.

This Special Issue will collect papers showing the applicability of the FEM-based methods to solve complex engineering problems from different fields, with an emphasis on fluid dynamics and related coupled problems (in particular, but not limited to, multiphase, fluid–structure interaction, and thermally coupled flows). While the emphasis of the SI is FEM, contributions devoted to applications of Finite Volume and Finite Difference approaches to engineering problems are also welcome. This issue will also highlight and discuss how tremendous growth in computer technology, as well as coupling with other numerical methods, will continue to have a significant impact on the evolution of FEM.

Dr. Julio Marti
Dr. Pavel Ryzhakov
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Finite element method
  • simulation
  • fluid dynamics
  • Navier–Stokes
  • coupled problems
  • fluid–structure interaction
  • multiphase flows
  • thermally coupled flows

Published Papers (14 papers)

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Research

12 pages, 17251 KiB  
Article
Inverse Approach of Parameter Optimization for Nonlinear Meta-Model Using Finite Element Simulation
by Seungpyo Hong, Dongseok Shin and Euysik Jeon
Appl. Sci. 2021, 11(24), 12026; https://0-doi-org.brum.beds.ac.uk/10.3390/app112412026 - 17 Dec 2021
Viewed by 2144
Abstract
Accurate and efficient estimation and prediction of the nonlinear behavior of materials during plastic working is a major issue in academic and industrial settings. Studies on property meta-models are being conducted to estimate and predict plastic working results. However, accurately representing strong nonlinear [...] Read more.
Accurate and efficient estimation and prediction of the nonlinear behavior of materials during plastic working is a major issue in academic and industrial settings. Studies on property meta-models are being conducted to estimate and predict plastic working results. However, accurately representing strong nonlinear properties using power-law and exponential models, which are typical meta-models, is difficult. The combination meta-model can be used to solve this problem, but the possible number of parameters increases. This causes a cost problem when using FE simulation. In this study, the accuracy of the nonlinear properties of materials and the number of iterations were compared for three typical meta-models and the proposed advanced meta-models considering stress–strain properties. A material property test was conducted using ASTM E8/E8M, and the meta-model was initialized using ASTM E646 and MATLAB Curve Fitting Toolbox. A finite element (FE) simulation was conducted for the meta-models, and the test and simulation results were compared in terms of the engineering stress–strain curve and the root-mean-square error (RMSE). In addition, an inverse method was applied for the FE simulation to estimate the true stress–strain properties, and the results were analyzed in terms of the RMSE and the number of iterations and simulations. Finally, the need for an advanced meta-model that exhibits strong nonlinearity was suggested. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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28 pages, 11024 KiB  
Article
Simulation of the Marangoni Effect and Phase Change Using the Particle Finite Element Method
by Billy-Joe Bobach, Romain Boman, Diego Celentano, Vincent E. Terrapon and Jean-Philippe Ponthot
Appl. Sci. 2021, 11(24), 11893; https://0-doi-org.brum.beds.ac.uk/10.3390/app112411893 - 14 Dec 2021
Cited by 10 | Viewed by 2550
Abstract
A simulation method is developed herein based on the particle finite element method (PFEM) to simulate processes with surface tension and phase change. These effects are important in the simulation of industrial applications, such as welding and additive manufacturing, where concentrated heat sources [...] Read more.
A simulation method is developed herein based on the particle finite element method (PFEM) to simulate processes with surface tension and phase change. These effects are important in the simulation of industrial applications, such as welding and additive manufacturing, where concentrated heat sources melt a portion of the material in a localized fashion. The aim of the study is to use this method to simulate such processes at the meso-scale and thereby gain a better understanding of the physics involved. The advantage of PFEM lies in its Lagrangian description, allowing for automatic tracking of interfaces and free boundaries, as well as its robustness and flexibility in dealing with multiphysics problems. A series of test cases is presented to validate the simulation method for these two effects in combination with temperature-driven convective flows in 2D. The PFEM-based method is shown to handle both purely convective flows and those with the Marangoni effect or melting well. Following exhaustive validation using solutions reported in the literature, the obtained results show that an overall satisfactory simulation of the complex physics is achieved. Further steps to improve the results and move towards the simulation of actual welding and additive manufacturing examples are pointed out. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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20 pages, 23827 KiB  
Article
Discrete and Continuum Approaches for Modeling Solids Motion Inside a Rotating Drum at Different Regimes
by César Martín Venier, Santiago Márquez Damián, Sergio Eduardo Bertone, Gabriel Darío Puccini, José María Risso and Norberto Marcelo Nigro
Appl. Sci. 2021, 11(21), 10090; https://0-doi-org.brum.beds.ac.uk/10.3390/app112110090 - 28 Oct 2021
Cited by 4 | Viewed by 2097
Abstract
In this work, the performance of discrete and continuum computational models for addressing granular flow dynamics in a rotating drum at different regimes is studied. The results are compared to the experimental observations obtained by image processing of a high-speed camera on a [...] Read more.
In this work, the performance of discrete and continuum computational models for addressing granular flow dynamics in a rotating drum at different regimes is studied. The results are compared to the experimental observations obtained by image processing of a high-speed camera on a pilot plant rotating drum. For the discrete modeling, Discrete Elements Method (DEM) through the open-source software LIGGGHTS(R) is used, while for the continuum model, the μ(I)-rheology is implemented in the general structure of a Volume-Of-Fluid (VOF) solver of the OpenFOAM(R) platform. Four test cases consisting of different sets of particles filling and rotational speed are considered and the results are analyzed in terms of solids distribution, the velocity of the particles, and mixing patterns. The solids distribution and velocities for each one of the tests considered are fairly similar between both computational techniques and the experimental observations. In general, DEM results show a higher level of agreement with the experiments, with minor differences that might be irrelevant in some cases (e.g., more splashing of particles for the fastest regimes). Among the drawbacks of the continuum model, it was unable to predict the slumping regime observed experimentally which can be attributed to the lack of a yield criterion and a slower dragging of the granular material when the drum is being accelerated, which can be attributed to the need of adding non-local effects to the rheology. On the other hand, the dynamic of the bed in the rolling and cascading regimes are accurately predicted by the continuum model in less time than DEM, even in a pilot plant scale system. These results suggest that the use of a continuum model with granular fluid rheology is more suited for simulating industrial-scale rotating drums at different regimes than DEM, but only if all the phenomenological features (i.e., yield criteria and non-local effects) are taken into account in the model. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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25 pages, 5423 KiB  
Article
Comparison between the Lagrangian and Eulerian Approach for Simulating Regular and Solitary Waves Propagation, Breaking and Run-Up
by Diana De Padova, Lucas Calvo, Paolo Michele Carbone, Domenico Maraglino and Michele Mossa
Appl. Sci. 2021, 11(20), 9421; https://0-doi-org.brum.beds.ac.uk/10.3390/app11209421 - 11 Oct 2021
Cited by 2 | Viewed by 2237
Abstract
The present paper places emphasis on the most widely used Computational Fluid Dynamics (CFD) approaches, namely the Eulerian and Lagrangian methods each of which is characterized by specific advantages and disadvantages. In particular, a weakly compressible smoothed particle (WCSPH) model, coupled with a [...] Read more.
The present paper places emphasis on the most widely used Computational Fluid Dynamics (CFD) approaches, namely the Eulerian and Lagrangian methods each of which is characterized by specific advantages and disadvantages. In particular, a weakly compressible smoothed particle (WCSPH) model, coupled with a sub-particle scale (SPS) approach for turbulent stresses and a new depth-integrated non-hydrostatic finite element model were employed for the simulation of regular breaking waves on a plane slope and solitary waves transformation, breaking and run-up. The validation of the numerical schemes was performed through the comparison between numerical and experimental data. The aim of this study is to compare the two modeling methods with an emphasis on their performance in the simulation of hydraulic engineering problems. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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14 pages, 5001 KiB  
Article
Improvement of the Zienkiewicz–Zhu Error Recovery Technique Using a Patch Configuration
by Mohd. Ahmed, Devinder Singh, Saeed AlQadhi and Majed A. Alrefae
Appl. Sci. 2021, 11(17), 8120; https://0-doi-org.brum.beds.ac.uk/10.3390/app11178120 - 01 Sep 2021
Cited by 2 | Viewed by 1929
Abstract
The Zienkiewicz–Zhu (ZZ) super-convergent patch recovery technique based on a node neighborhood patch configuration is used most widely for recovery of the stress field of a finite element analysis. In this study, an improved ZZ recovery technique using element neighborhood patch configuration is [...] Read more.
The Zienkiewicz–Zhu (ZZ) super-convergent patch recovery technique based on a node neighborhood patch configuration is used most widely for recovery of the stress field of a finite element analysis. In this study, an improved ZZ recovery technique using element neighborhood patch configuration is proposed. The improved recovery procedure is based on recovery of the stress field in the least-squares sense over an element patch that consists of the union of the elements surrounding the element under consideration. The proposed patch configuration provides more sampling points and improves the performance of the standard ZZ recovery technique. The effectiveness and reliability of the improved ZZ recovery approach is demonstrated through plane elastic and plastic plate problems. The problem domain is discretized with triangular and quadrilateral elements of different sizes. A comparison of the quality of error estimation using the ZZ recovery of derivative field and recovery of the displacement field using similar element neighborhood patch configurations is also presented. The numerical results show that the ZZ recovery technique and the displacement recovery technique, using a modified patch configuration, yield better results, convergence rate, and effectivity as compared with the standard ZZ super-convergent patch recovery technique. It is concluded that the improved ZZ recovery technique-based adaptive finite element analysis is very effective for converging a predefined accuracy with a significantly smaller number of degrees of freedom, especially in an elastic problem. It is also concluded that the improved ZZ recovery technique captures the plastic deformation problem solution errors more reliably than the standard ZZ recovery technique. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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16 pages, 3821 KiB  
Article
Direct Evaluation of the Stress Intensity Factors for the Single and Multiple Crack Problems Using the P-Version Finite Element Method and Contour Integral Method
by Jianming Zhang, Wensheng Yang, Jun Chen and Rui Xu
Appl. Sci. 2021, 11(17), 8111; https://0-doi-org.brum.beds.ac.uk/10.3390/app11178111 - 31 Aug 2021
Cited by 3 | Viewed by 1663
Abstract
Stress intensity factor (SIF) is one of three important parameters in classical linear elastic fracture mechanics (LEFM). The evaluation of SIFs is of great significance in the field of engineering structural and material damage assessment, such as aerospace engineering and automobile industry, etc. [...] Read more.
Stress intensity factor (SIF) is one of three important parameters in classical linear elastic fracture mechanics (LEFM). The evaluation of SIFs is of great significance in the field of engineering structural and material damage assessment, such as aerospace engineering and automobile industry, etc. In this paper, the SIFs of a central straight crack plate, a slanted single-edge cracked plate under end shearing, the offset double-edge cracks rectangular plate, a branched crack in an infinite plate and a crucifix crack in a square plate under bi-axial tension are extracted by using the p-version finite element method (P-FEM) and contour integral method (CIM). The above single- and multiple-crack problems were investigated, numerical results were compared and analyzed with results using other numerical methods in the literature such as the numerical manifold method (NMM), improved approach using the finite element method, particular weight function method and exponential matrix method (EMM). The effectiveness and accuracy of the present method are verified. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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18 pages, 8258 KiB  
Article
The Numerical Investigation of Structural Strength Assessment of LNG CCS by Sloshing Impacts Based on Multiphase Fluid Model
by Se-Yun Hwang and Jang-Hyun Lee
Appl. Sci. 2021, 11(16), 7414; https://0-doi-org.brum.beds.ac.uk/10.3390/app11167414 - 12 Aug 2021
Cited by 3 | Viewed by 1677
Abstract
Sloshing flows of liquid natural gas (LNG) with multi-phase flow characteristics consisting of liquids and gases can affect the load conditions and structural response of cargo containment systems (CCS). The compressible properties of the sloshing flow can limit the maximum pressure, so a [...] Read more.
Sloshing flows of liquid natural gas (LNG) with multi-phase flow characteristics consisting of liquids and gases can affect the load conditions and structural response of cargo containment systems (CCS). The compressible properties of the sloshing flow can limit the maximum pressure, so a multi-phase fluid model is required to represent the sloshing physics. In this study, we identified a suitable numerical model to simulate the sloshing flow and structural strength evaluation based on the inhomogeneous fluid model. The computational fluid dynamics (CFD) is based on a Eulerian domain model, which is in turn based on the constant volume based finite element method (CVFEM) in a commercial Reynolds-averaged Navier–Stokes CFD code (ANSYS CFX). It includes the interphase momentum transfer between the liquids and gasses. The physics for the sloshing assessment were considered to identify the main aspects of the inhomogeneous multiphase model. For numerical analysis of the sloshing, we conducted a sloshing simulation on the experimental data of the model scale to examine the validity of the results. The velocity of the sloshing flow was extended to the real scale and applied to a local two-way fluid structure interaction (FSI) analysis model. Structural strength evaluation of the LNG CCS by sloshing flow was performed by FSI analysis. Through the example of structural response analysis of Mark III type CCS, the results were discussed and effectiveness of the proposed structural response assessment model by sloshing was reviewed. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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15 pages, 3807 KiB  
Article
Topology Optimization Design and Experimental Research of a 3D-Printed Metal Aerospace Bracket Considering Fatigue Performance
by Yisheng Chen, Qianglong Wang, Chong Wang, Peng Gong, Yincheng Shi, Yi Yu and Zhenyu Liu
Appl. Sci. 2021, 11(15), 6671; https://0-doi-org.brum.beds.ac.uk/10.3390/app11156671 - 21 Jul 2021
Cited by 17 | Viewed by 3582
Abstract
In the aerospace industry, spacecraft often serve in harsh operating environments, so the design of ultra-lightweight and high-performance structures is a major requirement in aerospace structure design. In this article, a lightweight aerospace bracket considering fatigue performance was designed by topology optimization and [...] Read more.
In the aerospace industry, spacecraft often serve in harsh operating environments, so the design of ultra-lightweight and high-performance structures is a major requirement in aerospace structure design. In this article, a lightweight aerospace bracket considering fatigue performance was designed by topology optimization and manufactured by 3D-printing. Considering the requirements of assembly with a fixture for fatigue testing and avoiding stress concentration, a reconstructed model was presented by CAD software before manufacturing. To improve the fatigue performance of the structure, this article proposes the design idea of abstracting the practiced working condition of the bracket subjected to cycle loads in the vertical direction via a multiple load-case topology optimization problem by minimizing compliance under a variety of asymmetric extreme loading conditions. Parameter sweeping was used to improve the computational efficiency. The mass of the new bracket was reduced by 37% compared to the original structure. Both numerical simulation and the fatigue test were implemented to support the validity of the new bracket. This work indicates that the integration of the proposed topology optimization design method and additive manufacturing can be a powerful tool for the design of lightweight structures considering fatigue performance. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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16 pages, 4451 KiB  
Article
Modeling of Heat Phenomenon in Rolling Kinematic Pairs Using the Finite Element Method
by Jan Kosmol
Appl. Sci. 2021, 11(14), 6447; https://0-doi-org.brum.beds.ac.uk/10.3390/app11146447 - 13 Jul 2021
Cited by 4 | Viewed by 1516
Abstract
In the spindles of HSC (High Speed Cutting) machines with rolling bearings, higher temperatures in the bearings can be expected, which may affect the resistance to movement of the bearing itself. Therefore, to estimate these resistances, it is necessary to know the temperatures [...] Read more.
In the spindles of HSC (High Speed Cutting) machines with rolling bearings, higher temperatures in the bearings can be expected, which may affect the resistance to movement of the bearing itself. Therefore, to estimate these resistances, it is necessary to know the temperatures of the bearing components. The article presents the results of FEM simulation tests of temperature distribution in a rolling bearing. These studies were focused on assessing the influence of such features as the distribution of heat sources, the geometric form and size of the contact areas of the balls with the raceways, the conditions of heat convection to the environment and heat conduction inside the bearing. It has been recognized that FEM simulations for the default conditions offered by most commercial FEM systems can lead to out-of-the-box results. As part of the experimental research, conclusions from the simulation studies were verified. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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11 pages, 2935 KiB  
Article
Enhanced Coupling Coefficient in Dual-Mode ZnO/SiC Surface Acoustic Wave Devices with Partially Etched Piezoelectric Layer
by Huiping Xu, Sulei Fu, Rongxuan Su, Junyao Shen, Fei Zeng, Cheng Song and Feng Pan
Appl. Sci. 2021, 11(14), 6383; https://0-doi-org.brum.beds.ac.uk/10.3390/app11146383 - 10 Jul 2021
Cited by 10 | Viewed by 2223
Abstract
Surface acoustic wave (SAW) devices based on multi-layer structures have been widely used in filters and sensors. The electromechanical coupling factor (K2), which reflects energy-conversion efficiency, directly determines the bandwidth of the filter and the sensitivity of sensor. In this [...] Read more.
Surface acoustic wave (SAW) devices based on multi-layer structures have been widely used in filters and sensors. The electromechanical coupling factor (K2), which reflects energy-conversion efficiency, directly determines the bandwidth of the filter and the sensitivity of sensor. In this work, a new configuration of dual-mode (quasi-Rayleigh and quasi-Sezawa) SAW devices on a ZnO/SiC layered structure exhibiting significantly enhanced K2 was studied using the finite element method (FEM), which features in the partial etching of the piezoelectric film between the adjacent interdigitated electrodes (IDTs). The influences of piezoelectric film thickness, etching ratio, top electrodes, bottom electrodes, and the metallization ratio on the K2 were systematically investigated. The optimum K2 for the quasi-Rayleigh mode and quasi-Sezawa mode can exceed 12% and 8%, respectively, which increases by nearly 12 times and 2 times that of the conventional ZnO/SiC structure. Such significantly promoted K2 is of great benefit for better comprehensive performance of SAW devices. More specifically, a quasi-Rayleigh mode with relatively low acoustic velocity (Vp) can be applied into the miniaturization of SAW devices, while a quasi-Sezawa mode exhibiting a Vp value higher than 5000 m/s is suitable for fabricating SAW devices requiring high frequency and large bandwidth. This novel structure has proposed a viable route for fabricating SAW devices with excellent overall performance. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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17 pages, 18863 KiB  
Article
Numerical Simulation of Flame Retardant Polymers Using a Combined Eulerian–Lagrangian Finite Element Formulation
by Julio Marti, Jimena de la Vega, De-Yi Wang and Eugenio Oñate
Appl. Sci. 2021, 11(13), 5952; https://0-doi-org.brum.beds.ac.uk/10.3390/app11135952 - 26 Jun 2021
Cited by 2 | Viewed by 1731
Abstract
Many polymer-made objects show a trend of melting and dripping in fire, a behavior that may be modified by adding flame retardants (FRs). These affect materials properties, e.g., heat absorption and viscosity. In this paper, the effect of a flame retardant on the [...] Read more.
Many polymer-made objects show a trend of melting and dripping in fire, a behavior that may be modified by adding flame retardants (FRs). These affect materials properties, e.g., heat absorption and viscosity. In this paper, the effect of a flame retardant on the fire behavior of polymers in the UL 94 scenario is studied. This goal is achieved essentially by applying a new computational strategy that combines the particle finite element method for the polymer with an Eulerian formulation for air. The sample selected is a polypropylene (PP) with magnesium hydroxide at 30 wt.%. For modelling, values of density, conductivity, specific heat, viscosity, and Arrhenius coefficients are obtained from different literature sources, and experimental characterization is performed. However, to alleviate the missing viscosity at a high temperature, three viscosity curves are introduced on the basis of the viscosity curve provided by NIST and the images of the test. In the experiment, we burn the specimen under the UL 94 condition, recording the process and measuring the temperature evolution by means of three thermocouples. The UL 94 test is solved, validating the methodology and quantifying the effect of FR on the dripping behavior. The numerical results prove that well-adjusted viscosity is crucial to achieving good agreement between the experimental and numerical results in terms of the shape of the polymer and the temperature evolution inside the polymer. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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27 pages, 7026 KiB  
Article
Numerical Algorithms for Elastoplacity: Finite Elements Code Development and Implementation of the Mohr–Coulomb Law
by Gildas Yaovi Amouzou and Azzeddine Soulaïmani
Appl. Sci. 2021, 11(10), 4637; https://0-doi-org.brum.beds.ac.uk/10.3390/app11104637 - 19 May 2021
Cited by 7 | Viewed by 3048
Abstract
Two numerical algorithms for solving elastoplastic problems with the finite element method are presented. The first deals with the implementation of the return mapping algorithm and is based on a fixed-point algorithm. This method rewrites the system of elastoplasticity non-linear equations in a [...] Read more.
Two numerical algorithms for solving elastoplastic problems with the finite element method are presented. The first deals with the implementation of the return mapping algorithm and is based on a fixed-point algorithm. This method rewrites the system of elastoplasticity non-linear equations in a form adapted to the fixed-point method. The second algorithm relates to the computation of the elastoplastic consistent tangent matrix using a simple finite difference scheme. A first validation is performed on a nonlinear bar problem. The results obtained show that both numerical algorithms are very efficient and yield the exact solution. The proposed algorithms are applied to a two-dimensional rockfill dam loaded in plane strain. The elastoplastic tangent matrix is calculated by using the finite difference scheme for Mohr–Coulomb’s constitutive law. The results obtained with the developed algorithms are very close to those obtained via the commercial software PLAXIS. It should be noted that the algorithm’s code, developed under the Matlab environment, offers the possibility of modeling the construction phases (i.e., building layer by layer) by activating the different layers according to the imposed loading. This algorithmic and implementation framework allows to easily integrate other laws of nonlinear behaviors, including the Hardening Soil Model. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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22 pages, 974 KiB  
Article
Consistent Implicit Time Integration for Viscoplastic Modelingof Subsidence above Hydrocarbon Reservoirs
by Aldo Ghisi, Massimiliano Cremonesi, Umberto Perego, Anna Corradi, Fabrizio Gemelli and Stefano Mantica
Appl. Sci. 2021, 11(8), 3513; https://0-doi-org.brum.beds.ac.uk/10.3390/app11083513 - 14 Apr 2021
Viewed by 1662
Abstract
The viscoplastic model proposed by Vermeer and Neher in 1999 is still currently used in the oil and gas industry for subsidence modeling, to predict the deformation of the ground surface induced by hydrocarbon withdrawal from underground reservoirs. Even though several different implementations [...] Read more.
The viscoplastic model proposed by Vermeer and Neher in 1999 is still currently used in the oil and gas industry for subsidence modeling, to predict the deformation of the ground surface induced by hydrocarbon withdrawal from underground reservoirs. Even though several different implementations of this model have been proposed in the literature, also very recently, a consistent fully implicit implementation is still missing, probably due to the technical difficulties involved in the rigorous derivation of the analytical tangent matrix. To fill this gap and to provide an effective tool to the engineering community, a fully implicit backward Euler integration is proposed and validated in this work. The consistent expression of the tangent stiffness matrix is also derived analytically, and its validation strategy is described in detail. The model was implemented in a commercial finite element code through a user-defined material subroutine. The advantages of the proposed implicit formulation in terms of stability with respect to an explicit formulation were assessed and validated. The examples include studies at material point level and at field scale for a case study of subsidence in a synthetic reservoir. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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17 pages, 7837 KiB  
Article
Numerical Analysis of the Load-Displacement Behaviour of Cast-in-Place Progressive Anchorage in Reinforced Concrete Members
by Matúš Farbák, Jozef Jošt, Richard Hlinka and Miroslav Rosmanit
Appl. Sci. 2021, 11(5), 2343; https://0-doi-org.brum.beds.ac.uk/10.3390/app11052343 - 06 Mar 2021
Cited by 4 | Viewed by 2069
Abstract
Modern construction requirements for building structures are currently focused on reducing the time required for construction, dealing with the lack of qualified human resources and ensuring comprehensive construction work quality. The problems mentioned above of today’s construction industry are significantly reduced by modern [...] Read more.
Modern construction requirements for building structures are currently focused on reducing the time required for construction, dealing with the lack of qualified human resources and ensuring comprehensive construction work quality. The problems mentioned above of today’s construction industry are significantly reduced by modern prefabrication and the efficient use of the most common building materials—steel and concrete. Critical components of such construction systems are their joints. Currently, there are many different types of joints of precast concrete structural elements. Integral parts of these joints are the various anchorages. For connecting load-bearing components, cast-in-place anchor systems are preferred to post-installed ones. The appropriate design of this small but crucial structural component is a complicated engineering issue in some cases. The finite element method (FEM) represents a practical opportunity to design and analyze anchorage systems in detail. A detailed numerical study based on an experimental program was performed to understand cast-in-place anchors’ real behavior and clarify some of the parameters of their design. This paper explains the creation of a numerical model, compares the FEM model with the performed experiments and presents the interesting results of the performed parametric study. Full article
(This article belongs to the Special Issue Element-Based Methods for the Solution of Engineering Problems)
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