materials-logo

Journal Browser

Journal Browser

Numerical Methods and Optimization of Structures: FEM

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Materials Simulation and Design".

Deadline for manuscript submissions: closed (30 March 2021) | Viewed by 12912

Special Issue Editor

Faculty of Wood Technology, Uniwersytet Przyrodniczy w Poznaniu, Poznań, Poland
Interests: finite element method (FEM); numerical optimization; wood and wood-based composites; beams, honeycombs, plates, shells; springs and foams; fasteners and joints; thin-walled structures; experimental investigations
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The Special Issue, "Numerical Methods and Optimization of Structures: FEM" will address advances in the applications of the finite element method (FEM) and numerical optimization methods for modeling and analyzing various mechanical problems in materials science, joints and fasteners, furniture structures and other products manufactured of wood or wood-based composites. Numerical modeling is very important in the sustainable design of products made of bio-based materials. They are used in furniture, boatbuilding, automotive, and civil engineering industries. Designers are looking for structures with high strength and stiffness at an optimally low weight. The use of numerical methods reduces the costs of prototyping and validation, facilitates the diagnosis of damage occurrence, and enables the assessment of product safety.

Original articles on numerical modeling (FEM) and the optimization of all types of materials, joints, and structures based on wood and wood-based composites under various operating conditions are invited. The published work will provide a complete understanding of how to improve the stiffness and strength of materials, as well as improved joints, structural members, and products. Contributions can be submitted in the form of original research papers and review articles.

Prof. Dr. Jerzy Smardzewski
Guest Editor

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. Materials 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 2600 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 (FEM)
  • numerical optimization
  • wood and wood-based composites
  • beams, honeycombs, plates, shells
  • springs and foams
  • fasteners and joints
  • thin-walled structures
  • experimental investigations

Published Papers (8 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

11 pages, 3697 KiB  
Article
Near-Surface Mounted Reinforcement of Sawn Timber Beams-FEM Approach
Materials 2021, 14(11), 2780; https://doi.org/10.3390/ma14112780 - 24 May 2021
Cited by 2 | Viewed by 1195
Abstract
The demand for timber has increased significantly in recent years. Therefore, reliable tools are needed to predict the mechanical properties of sawn timber, especially for structural applications. Very complex models require a lot of input data for analysis, which cannot always be guaranteed, [...] Read more.
The demand for timber has increased significantly in recent years. Therefore, reliable tools are needed to predict the mechanical properties of sawn timber, especially for structural applications. Very complex models require a lot of input data for analysis, which cannot always be guaranteed, especially in industrial practice. Thus, a simplified model for material description was developed and assessed with experiments (static bending tests carried out in accordance with the guidelines suggested in the European standard EN 408) and an analytical approach (gamma method according to the guidelines given in the European standard EN 1995). The effective stiffness was calculated as a major parameter, which has an influence on the elements’ behavior. The model included a near-surface mounted (NSM) local reinforcement technique, with CFRP strips of Scots pine timber beams being subjected to bending stresses. It is anticipated that the developed model can be a starting point for the repair engineering field, contributing to decision-making regarding conservation technique selection and range. Next, improvements of the model will provide more and more realistic results for numerical analysis in terms of the obtained failure mechanisms for sawn timber elements. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

11 pages, 17468 KiB  
Article
Stochastic Thermal Properties of Laminates Filled with Long Fibers
Materials 2021, 14(10), 2511; https://doi.org/10.3390/ma14102511 - 12 May 2021
Viewed by 980
Abstract
In this paper, the stochastic parameters of the effective thermal conductivity of multilayer composites are considered. The examined specimens of composites were built with a different number of layers and each had a different saturation density of a composite matrix with fibers. For [...] Read more.
In this paper, the stochastic parameters of the effective thermal conductivity of multilayer composites are considered. The examined specimens of composites were built with a different number of layers and each had a different saturation density of a composite matrix with fibers. For each case of laminate built with a prescribed number of layers and assumed saturation density, 10,000 tests of its effective thermal conductivity were carried out using numerical experiments. It was assumed that the fibers located in each layer were rectilinear, had a circular cross-section and that they could take random positions in their repeatable volume elements (RVEs). In view of the mentioned assumptions, the heat flux passing throughout a cross-section of a composite sample, perpendicular to the fibers’ direction, was considered. The probability density functions were fitted to the obtained data and then the chosen stochastic parameters of the effective thermal conductivity coefficients were determined. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

28 pages, 37414 KiB  
Article
Modeling Structural Dynamics Using FE-Meshfree QUAD4 Element with Radial-Polynomial Basis Functions
Materials 2021, 14(9), 2288; https://doi.org/10.3390/ma14092288 - 28 Apr 2021
Cited by 1 | Viewed by 1393
Abstract
The PU (partition-of-unity) based FE-RPIM QUAD4 (4-node quadrilateral) element was proposed for statics problems. In this element, hybrid shape functions are constructed through multiplying QUAD4 shape function with radial point interpolation method (RPIM). In the present work, the FE-RPIM QUAD4 element is further [...] Read more.
The PU (partition-of-unity) based FE-RPIM QUAD4 (4-node quadrilateral) element was proposed for statics problems. In this element, hybrid shape functions are constructed through multiplying QUAD4 shape function with radial point interpolation method (RPIM). In the present work, the FE-RPIM QUAD4 element is further applied for structural dynamics. Numerical examples regarding to free and forced vibration analyses are presented. The numerical results show that: (1) If CMM (consistent mass matrix) is employed, the FE-RPIM QUAD4 element has better performance than QUAD4 element under both regular and distorted meshes; (2) The DLMM (diagonally lumped mass matrix) can supersede the CMM in the context of the FE-RPIM QUAD4 element even for the scheme of implicit time integration. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

10 pages, 1205 KiB  
Article
Concurrent Lamination and Tapering Optimization of Cantilever Composite Plates under Shear
Materials 2021, 14(9), 2285; https://doi.org/10.3390/ma14092285 - 28 Apr 2021
Cited by 7 | Viewed by 1467
Abstract
The operational performance of cantilever composite structures can benefit from both stiffness tailoring and geometric design, yet, this potential has not been fully utilized in existing studies. The present study addresses this problem by simultaneously optimizing layer and taper angles of cantilever laminates. [...] Read more.
The operational performance of cantilever composite structures can benefit from both stiffness tailoring and geometric design, yet, this potential has not been fully utilized in existing studies. The present study addresses this problem by simultaneously optimizing layer and taper angles of cantilever laminates. The design objective is selected as minimizing the average deflection of the tip edge subjected to shear loads while keeping the length and total volume constant. The plate stiffness properties are described by lamination parameters to eliminate the possible solution dependency on the initial assumptions regarding laminate configuration. The responses are computed via finite element analyses, while optimal design variables are determined using genetic algorithms. The results demonstrate that the plate aspect ratio significantly influences the effectiveness of stiffness tailoring and tapering as well as the optimal layer and taper angles. In addition, concurrent exploitation of the lamination characteristics and plate geometry is shown to be essential for achieving maximum performance. Moreover, individual and simultaneous optimization of layer and taper angles produce different optimal results, indicating the possible drawback of using sequential approaches in similar composite design problems. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

24 pages, 4658 KiB  
Article
Vertex Displacement-Based Discontinuous Deformation Analysis Using Virtual Element Method
Materials 2021, 14(5), 1252; https://doi.org/10.3390/ma14051252 - 06 Mar 2021
Cited by 1 | Viewed by 1579
Abstract
To avoid disadvantages caused by rotational degrees of freedom in the original Discontinuous Deformation Analysis (DDA), a new block displacement mode is defined within a time step, where displacements of all the block vertices are taken as the degrees of freedom. An individual [...] Read more.
To avoid disadvantages caused by rotational degrees of freedom in the original Discontinuous Deformation Analysis (DDA), a new block displacement mode is defined within a time step, where displacements of all the block vertices are taken as the degrees of freedom. An individual virtual element space V1(Ω) is defined for a block to illustrate displacement of the block using the Virtual Element Method (VEM). Based on VEM theory, the total potential energy of the block system in DDA is formulated and minimized to obtain the global equilibrium equations. At the end of a time step, the vertex coordinates are updated by adding their incremental displacement to their previous coordinates. In the new method, no explicit expression for the displacement u is required, and all numerical integrations can be easily computed. Four numerical examples originally designed by Shi are analyzed, verifying the effectiveness and precision of the proposed method. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

9 pages, 2385 KiB  
Article
Homogenization of Radial Temperature by a Tungsten Sink in Sublimation Growth of 45 mm AlN Single Crystal
Materials 2020, 13(23), 5553; https://doi.org/10.3390/ma13235553 - 06 Dec 2020
Cited by 2 | Viewed by 1555
Abstract
To reduce the thermal stress during the sublimation growth of 45 mm AlN single crystal, a tungsten sink was put on the top of the crucible lid. Numerical experiments showed that the radial temperature gradient was reduced due to the homogenization effect on [...] Read more.
To reduce the thermal stress during the sublimation growth of 45 mm AlN single crystal, a tungsten sink was put on the top of the crucible lid. Numerical experiments showed that the radial temperature gradient was reduced due to the homogenization effect on temperature as a result of the sink. Therefore, this simple tungsten sink method has the potential to grow large-size AlN ingots with fewer cracks. It also reveals that enhancing the heat exchange of the crucible lid is an effective way to improve the quality of crystal growth. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

20 pages, 63495 KiB  
Article
Numerical Optimization Simulation of Synchronous Four-Wing Rotor
Materials 2020, 13(23), 5353; https://doi.org/10.3390/ma13235353 - 25 Nov 2020
Cited by 1 | Viewed by 1337
Abstract
The mixer is the most widely used batch mixing equipment in the rubber industry. The rotor is a core component and has a great impact on the mixing effect of the equipment. The current rotor structure design is done empirically, being tightly dependent [...] Read more.
The mixer is the most widely used batch mixing equipment in the rubber industry. The rotor is a core component and has a great impact on the mixing effect of the equipment. The current rotor structure design is done empirically, being tightly dependent on practical experience. This paper proposes a method for optimizing the rotor structure by using optimization algorithms combined with numerical simulation technology. Using MATLAB software, a parametric design program for synchronous rotors and a set of optimization programs for the particle swarm optimization (PSO) algorithm were written. The global distribution index was used as the fitness function to optimize the synchronous rotor configuration. A comparative analysis of the rotors before and after optimization shows that the optimization process is feasible, and the results are reliable. This provides new ideas for the design and development of mixer rotors. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Figure 1

21 pages, 6013 KiB  
Article
Experimental and Numerical Study on Withdrawal Strength of Different Types of Auxetic Dowels for Furniture Joints
Materials 2020, 13(19), 4252; https://doi.org/10.3390/ma13194252 - 24 Sep 2020
Cited by 15 | Viewed by 2414
Abstract
Studies on the application of auxetic metamaterials and structures in furniture joints are very limited. However, they have huge potential for use in ready-to-assemble furniture. This study aimed to design and produce different types of auxetic dowels in 3D printing technology, and experimentally [...] Read more.
Studies on the application of auxetic metamaterials and structures in furniture joints are very limited. However, they have huge potential for use in ready-to-assemble furniture. This study aimed to design and produce different types of auxetic dowels in 3D printing technology, and experimentally and numerically analyze the withdrawal strength of these dowels. In the scope of the study, 24 auxetic dowels with different types and size of inclusions, different diameter of holes, and a non-auxetic reference dowel were designed and produced with appropriate muffs. Dowels were 3D printed from polyamide (PA12). Poisson’s ratios, withdrawal strength, contact pressures, and friction coefficients of dowels were determined theoretically by means of numerical analyses and real static compression tests. After the pre-production of dowels, the dowels with triangular inclusions have not been found to have sufficient strength and stiffness. Withdrawal strength of dowels decreased as the size of inclusions is decreased, or dowel hole diameter is increased. Furthermore, contact pressures and stresses in auxetic dowels were considerably lower than non-auxetic dowels under the withdrawal force. Full article
(This article belongs to the Special Issue Numerical Methods and Optimization of Structures: FEM)
Show Figures

Graphical abstract

Back to TopTop