Multistage topology optimization of induction heating apparatus in time domain electromagnetic field with magnetic nonlinearity

2019 ◽  
Vol 38 (3) ◽  
pp. 1009-1022
Author(s):  
Hiroshi Masuda ◽  
Yoshifumi Okamoto ◽  
Shinji Wakao
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Induction Heating ◽  
Time Domain ◽  
Computation Time ◽  
Design Domain ◽  
Element Mesh ◽  
Content Type ◽  
Actual Application ◽  
Application Model

Purpose The purpose of this paper is to solve efficiently the topology optimization (TO) in time domain problem with magnetic nonlinearity requiring a large-scale finite element mesh. As an actual application model, the proposed method is applied to induction heating apparatus. Design/methodology/approach To achieve TO with efficient computation time, a multistage topology is proposed. This method can derive the optimum structure by repeatedly reducing the design domain and regenerating the finite element mesh. Findings It was clarified that the structure derived from proposed method can be similar to the structure derived from the conventional method, and that the computation time can be made more efficient by parameter tuning of the frequency and volume constraint value. In addition, as a time domain induction heating apparatus problem of an actual application model, an optimum topology considering magnetic nonlinearity was derived from the proposed method. Originality/value Whereas the entire design domain must be filled with small triangles in the conventional TO method, the proposed method requires finer mesh division of only the stepwise-reduced design domain. Therefore, the mesh scale is reduced, and there is a possibility that the computation time for TO can be shortened.

Optimization design of titanium alloy connecting rod based on structural topology optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bin Zheng ◽  
Yi Cai ◽  
Kelun Tang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Optimization Design ◽  
Equivalent Stress ◽  
Connecting Rod ◽  
Element Analysis ◽  
Content Type ◽  
The Finite Element Analysis ◽  
Maximum Equivalent Stress

Purpose The purpose of this paper is to realize the lightweight of connecting rod and meet the requirements of low energy consumption and vibration. Based on the structural design of the original connecting rod, the finite element analysis was conducted to reduce the weight and increase the natural frequencies, so as to reduce materials consumption and improve the energy efficiency of internal combustion engine. Design/methodology/approach The finite element analysis, structural optimization design and topology optimization of the connecting rod are applied. Efficient hybrid method is deployed: static and modal analysis; and structure re-design of the connecting rod based on topology optimization. Findings After the optimization of the connecting rod, the weight is reduced from 1.7907 to 1.4875 kg, with a reduction of 16.93%. The maximum equivalent stress of the optimized connecting rod is 183.97 MPa and that of the original structure is 217.18 MPa, with the reduction of 15.62%. The first, second and third natural frequencies of the optimized connecting rod are increased by 8.89%, 8.85% and 11.09%, respectively. Through the finite element analysis and based on the lightweight, the maximum equivalent stress is reduced and the low-order natural frequency is increased. Originality/value This paper presents an optimization method on the connecting rod structure. Based on the statics and modal analysis of the connecting rod and combined with the topology optimization, the size of the connecting rod is improved, and the static and dynamic characteristics of the optimized connecting rod are improved.

Optimization of the shape of an induction heating device in the presence of skin effect in the coils

2019 ◽  
Vol 39 (2) ◽  
pp. 525-531
Author(s):  
Giovanni Aiello ◽  
Salvatore Alfonzetti ◽  
Santi Agatino Rizzo ◽  
Nunzio Salerno
Keyword(s):  
Finite Element ◽  
Induction Heating ◽  
Dirichlet Boundary ◽  
Computing Time ◽  
Proximity Effects ◽  
Content Type ◽  
Hybrid Finite Element Method ◽  
Electromagnetic Problems ◽  
Hybrid Finite Element ◽  
Heating Device

Purpose The optimization of the cross section of an axisymmetric induction heating device is performed by means of genetic algorithms (GAs). Design/methodology/approach The hybrid finite element method–Dirichlet boundary condition iteration method is used to deal with the unbounded nature of the field. The formulation of the electromagnetic problems takes into account skin and proximity effects in the source currents. Findings The convergence of GAs towards the optimum is very fast, since less than a thousand analyses have been necessary. Originality/value A special derivation of the finite element global system is presented which allows us to save computing time.

Design of Phononic Materials Using Multiresolution Topology Optimization

2013 ◽  
Author(s):  
Sandro L. Vatanabe ◽  
Emilio C. N. Silva
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
High Resolution ◽  
Elastic Materials ◽  
Element Mesh ◽  
Computational Framework ◽  
Numerical Examples ◽  
Acoustic Waveguides ◽  
Acoustic Wave Devices ◽  
Multiresolution Topology Optimization

In this work the Multiresolution Topology Optimization (MTOP) scheme is investigated to obtain high resolution designs of phononic (elastic) materials, focusing primarily on acoustic waveguides. We demonstrate via numerical examples that the resolution of the design can be significantly improved without refining the finite element mesh. The first one is the simplest case where one might be interested in maximizing the energy reaching certain parts of the domain. The second and more interesting example is the creation of different propagation patterns for different frequencies, thus creating smart filters. The results demonstrate the power and potential of our computational framework to design sophisticated acoustic wave devices.

scholarly journals Comparative Study of Peridynamics and Finite Element Method for Practical Modeling of Defects Cracks in Topology Optimization

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1407
Author(s):  
Peyman Lahe Motlagh ◽  
Adnan Kefal
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Comparative Study ◽  
Strain Energy ◽  
Optimality Criteria ◽  
Design Stage ◽  
Design Domain ◽  
Optimum Topology ◽  
Strain Stress

Recently, topology optimization of structures with cracks becomes an important topic for avoiding manufacturing defects at the design stage. This paper presents a comprehensive comparative study of peridynamics-based topology optimization method (PD-TO) and classical finite element topology optimization approach (FEM-TO) for designing lightweight structures with/without cracks. Peridynamics (PD) is a robust and accurate non-local theory that can overcome various difficulties of classical continuum mechanics for dealing with crack modeling and its propagation analysis. To implement the PD-TO in this study, bond-based approach is coupled with optimality criteria method. This methodology is applicable to topology optimization of structures with any symmetric/asymmetric distribution of cracks under general boundary conditions. For comparison, optimality criteria approach is also employed in the FEM-TO process, and then topology optimization of four different structures with/without cracks are investigated. After that, strain energy and displacement results are compared between PD-TO and FEM-TO methods. For design domain without cracks, it is observed that PD and FEM algorithms provide very close optimum topologies with a negligibly small percent difference in the results. After this validation step, each case study is solved by integrating the cracks in the design domain as well. According to the simulation results, PD-TO always provides a lower strain energy than FEM-TO for optimum topology of cracked structures. In addition, the PD-TO methodology ensures a better design of stiffer supports in the areas of cracks as compared to FEM-TO. Furthermore, in the final case study, an intended crack with a symmetrically designed size and location is embedded in the design domain to minimize the strain energy of optimum topology through PD-TO analysis. It is demonstrated that hot-spot strain/stress regions of the pristine structure are the most effective areas to locate the designed cracks for effective redistribution of strain/stress during topology optimization.

A novel numerical method for the solution of nonlinear equations with applications to heat transfer

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
J.N. Reddy ◽  
Matthew Martinez ◽  
Praneeth Nampally
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Boundary Conditions ◽  
Numerical Method ◽  
Mixed Boundary ◽  
Salient Feature ◽  
Two Dimensions ◽  
Element Mesh ◽  
Content Type ◽  
Linear Differential

Purpose The purpose of this study is to extend a novel numerical method proposed by the first author, known as the dual mesh control domain method (DMCDM), for the solution of linear differential equations to the solution of nonlinear heat transfer and like problems in one and two dimensions. Design/methodology/approach In the DMCDM, a mesh of finite elements is used for the approximation of the variables and another mesh of control domains for the satisfaction of the governing equation. Both meshes fully cover the domain but the nodes of the finite element mesh are inside the mesh of control domains. The salient feature of the DMCDM is that the concept of duality (i.e. cause and effect) is used to impose boundary conditions. The method possesses some desirable attributes of the finite element method (FEM) and the finite volume method (FVM). Findings Numerical results show that he DMCDM is more accurate than the FVM for the same meshes used. Also, the DMCDM does not require the use of any ad hoc approaches that are routinely used in the FVM. Originality/value To the best of the authors’ knowledge, the idea presented in this work is original and novel that exploits the best features of the best competing methods (FEM and FVM). The concept of duality is used to apply gradient and mixed boundary conditions that FVM and its variant do not.

Design optimization of key components’ spatial position of unilateral axle counting sensor

Sensor Review ◽  
2018 ◽  
Vol 38 (3) ◽  
pp. 261-268
Author(s):  
Weiming Tong ◽  
Yanlong Liu ◽  
Xianji Jin ◽  
Zhongwei Li ◽  
Jian Guan
Keyword(s):  
Finite Element ◽  
Design Optimization ◽  
Operation Time ◽  
Spatial Location ◽  
Optimization Method ◽  
Element Mesh ◽  
Content Type ◽  
Sensor Structure ◽  
Excitation Coil ◽  
Railway Signal Device

PurposeThe unilateral axle counting sensor is an important railway signal device that detects a train. For efficient and stable detection, the amplitude of induced electromotive force and its changes must be big enough. Therefore, the purpose of this study is to find a way to design and optimize the sensor structure quickly and accurately.Design/methodology/approachWith the help of extensive electromagnetic field calculations, the study puts forward a modified model based on the finite element method, establishes an independent air domain around the sensor, wheel and the railway and adopts a unique grid division method. It offers a design optimization method of the induction coil angles and its spatial location with respect to the excitation coil by using the combination weighting algorithm.FindingsThe modified modeling method can greatly reduce the number of finite element mesh and the operation time, and the method can also be applied to other areas. The combination weighting algorithm can optimize the structure of the sensor quickly and accurately.Originality/valueThis study provides a way to design and optimize the structure of the sensor and a theoretical basis for the development. The results can improve and expand the technology of the axle counting sensor.

Topology Optimization of Geometrically Non-Linear Structures Using Iso-XFEM Method

2014 ◽  
Vol 627 ◽  
pp. 121-124
Author(s):  
M. Abdi ◽  
I. Ashcroft ◽  
R.D. Wildman
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Optimization Method ◽  
Test Case ◽  
Optimization Approach ◽  
Element Mesh ◽  
Non Linear ◽  
Linear Behaviour ◽  
Element Method

Iso-XFEM is an evolutionary-based topology optimization method which couples the extended finite element method (X-FEM) with an isoline/isosurface optimization approach, enabling a smooth and accurate representation of the design boundary in a fixed-grid finite element mesh. This paper investigates the application of the Iso-XFEM method to the topology optimization of structures which experience large deformation. The total Lagrangian formulation of the finite element method is employed to model the geometrically non-linear behaviour and equilibrium is found by implementing the Newton-Raphson method in each evolution. A cantilever beam is considered as a test case and the Iso-XFEM solutions obtained from linear and non-linear designs are compared with bi-directional evolutionary structural optimization (BESO) solutions.

8-node and 12-node plane elements based on assumed stress quasi-conforming method immune to distorted mesh

2017 ◽  
Vol 34 (8) ◽  
pp. 2731-2751 ◽  
Author(s):  
Changsheng Wang ◽  
Yang Wang ◽  
Caixia Yang ◽  
Xiangkui Zhang ◽  
Ping Hu
Keyword(s):  
Finite Element ◽  
Analytical Solutions ◽  
Element Mesh ◽  
Content Type ◽  
Mesh Model ◽  
Distorted Mesh ◽  
New Strategy ◽  
Discrete Methods ◽  
Element Boundary ◽  
Fundamental Analytical Solutions

Purpose Severe accuracy loss may occur when finite element comes to the distorted mesh model, and the calculation may fail when element mesh degenerates into concave quadrangle or the element boundary is curved. This is a valuable research topic, and many efforts have been made to develop new finite element models. This paper aims to propose two quasi-conforming membrane elements based on the assumed stress quasi-conforming method and fundamental analytical solutions to overcome the difficulties. Design/methodology/approach First, the fundamental analytical solutions which satisfied both the equilibrium and the compatibility relations of plane stress problem are used as the initial assumed stress of both elements. Then, the stress-function matrices are used as the weighted functions to weaken the strain-displacement equations, which makes only string-net functions on the boundary of the elements are needed in the process of strain integration. Finally, boundary interpolation functions expressed by unknown nodal displacement parameters are adopted to the process of strain integration. Findings The formulations of both elements are simple and concise, and the elements are immune to the distorted mesh, which can be used to the mesh shape degenerates into a triangle or concave quadrangle and curved-side element. The results of the numerical tests have proven that the new models possess high accuracy. Originality/value New formulations of quasi-conforming method are described is detail, and the new strategy exhibits advantages of both analytical and discrete methods.

Topologically optimized axle carrier for Formula Student produced by selective laser melting

2019 ◽  
Vol 25 (9) ◽  
pp. 1545-1551
Author(s):  
Ondřej Vaverka ◽  
Daniel Koutny ◽  
David Palousek
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Selective Laser Melting ◽  
Experimental Testing ◽  
Fem Analysis ◽  
Design Stage ◽  
Laser Melting ◽  
Content Type ◽  
Race Car ◽  
Process Manufacturing

Purpose This paper aims to present the design process, manufacturing and testing of a prototype of an axle carrier for Formula Student race car. The axle carrier is topologically optimized and additively manufactured using selective laser melting (SLM). Design/methodology/approach The shape of the axle carrier was created in three design stages using topology optimization and four additional design stages based on finite element calculations and experimental testing. Topology optimization was performed on the basis of relevant load cases. The sixth design stage was manufactured by SLM and then tested on a loading device together with photogrammetry measurement to obtain the real deformation. Measured deformations were compared with deformation calculated by the finite element method (FEM), verified and experiences used in the last design stage. Findings An additively manufactured axle carrier has a minimal safety factor of 1.2 according to experimental testing. The weight and maximal deformations are comparable with the milled part, although the material has about 50 per cent worse yield strength. The topologically optimized axle carrier proved big potential in the effective distribution of material and the improvement of toughness. Practical implications This paper helps the Formula Student team to enhance the driving performance while keeping low weight. It also improves further development and upgrading of the race car. Originality/value The whole design of the topologically optimized part was investigated – from estimation of the loads to experimental verification of FEM analysis on real part.

scholarly journals DESIGN, DEVELOPMENT & ANALYSIS OF AIRCRAFT DROOP NOSE RIBS BY USING OPTIMIZATION TECHNIQUE

2021 ◽  
Vol 10 (5) ◽  
pp. 32-46
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Mesh Generation ◽  
Optimization Method ◽  
Finite Element Mesh ◽  
Generic Model ◽  
Aircraft Wing ◽  
Element Mesh ◽  
Wing Model ◽  
Wing Geometry

This master thesis work presents the development of a parameterized automated generic model for the structural design of an aircraft wing. Furthermore, in order to perform finite element analysis on the aircraft wing geometry, the process of finite element mesh generation is automated. The generic model that is developed in this regard is able to automate the process of creation and modification of the aircraft wing geometry based on a series of parameters which define the geometrical characteristics of wing panels, wing spars and wing ribs. Two different approaches are used for the creation of the generic model of an aircraft wing which are “Knowledge Pattern” and “Power Copy with Visual Basic Scripting” using the CATIA V5 Software. A performance comparison of the generic wing model based on these two approaches is also performed. In the early stages of the aircraft design process, an estimate of the structural characteristic of the aircraft wing is desirable for which a surface structural analysis (using 2D mesh elements) is more suitable. In this regard, the process of finite element mesh generation for the generic wing model is automated. Furthermore, the finite element mesh is updated based on any changes in geometry and the shape of the wing panels, wing spars or wing ribs, and ensure that all the mesh elements are always properly connected at the nodes. The automated FE mesh generated can be used for performing the structural analysis on an aircraft wing. Topology optimization has for a considerable time been applied successfully in the automotive industry, but still has not become a mainstream technology for the design of aircraft components.. Also, aircraft components are often stability designs and the compliance based topology optimization method still lacks the ability to deal with any buckling criteria. The present paper considers the use of the compliance formulated topology optimization method and detailed sizing/shape optimization methods to the design of aircraft components but also discusses the difficulties in obtaining correct loading and boundary conditions for finite element based analysis/optimization of components that are integral parts of a larger structure.

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