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.

Predicting the Benefits of Topology Optimization

2015 ◽  
Author(s):  
Shiguang Deng ◽  
Krishnan Suresh
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Shape Optimization ◽  
Systematic Method ◽  
Topological Sensitivity ◽  
Numerical Examples ◽  
Initial Design

Topology optimization is a systematic method of generating designs that maximize specific objectives. While it offers significant benefits over traditional shape optimization, topology optimization can be computationally demanding and laborious. Even a simple 3D compliance optimization can take several hours. Further, the optimized topology must typically be manually interpreted and translated into a CAD-friendly and manufacturing friendly design. This poses a predicament: given an initial design, should one optimize its topology? In this paper, we propose a simple metric for predicting the benefits of topology optimization. The metric is derived by exploiting the concept of topological sensitivity, and is computed via a finite element swapping method. The efficacy of the metric is illustrated through numerical examples.

Application of the TELEMAC-2D Model in the Fluvial Hydrodinamics Simulation and Reproduction of Flood Patterns

2019 ◽  
Vol 396 ◽  
pp. 187-196
Author(s):  
Aldair Forster ◽  
Juliana Costi ◽  
Wiliam Correa Marques ◽  
André Gustavo Wormsbecher ◽  
Antonio Raylton Rodrigues Bendo
Keyword(s):  
Finite Element ◽  
High Resolution ◽  
Shallow Water ◽  
Shallow Water Equations ◽  
Numerical Models ◽  
Finite Element Mesh ◽  
Element Mesh ◽  
The City ◽  
2D Model ◽  
National Water

. The increased occurrence of floods in the city of Rio do Sul (SC), even with the creation of dams to contain floods, show that non-structural measures can be good alternatives to reduce losses in the region. Numerical flood modeling has been widely used to anticipate risks and assist in decisionmaking. One of the numerical models that is being used to simulate floods is TELEMAC-2D, which is able to simulate the hydrodynamics of open channels by solving the shallow water equations in a domain discretized by an unstructured finite element mesh. We used the TELEMAC-2D model tosimulate the dynamics of the rivers of the region of Rio do Sul throughout the year of 2013, period during which a flood with large proportions occurred in September. Fluviometric data avaliable from the National Water Agency and high resolution (1 m) topographic data provided by government agen-cies of Santa Catarina were used in the simulation. The results show that the model performed well in simulating the maximum flood extension occurred in September, however, the simulations were underestimated for most of the time, indicating that calibrations in the model can still be performed.

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.

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.

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.

scholarly journals Multiresolution Topology Optimization of Large-Deformation Path-Generation Compliant Mechanisms with Stress Constraints

2021 ◽  
Vol 11 (6) ◽  
pp. 2479
Author(s):  
Joseph Reinisch ◽  
Erich Wehrle ◽  
Johannes Achleitner
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Nonlinear Finite Element Analysis ◽  
Stress Constraints ◽  
Nonlinear Finite Element ◽  
Path Generation ◽  
Element Analysis ◽  
Multiresolution Topology Optimization

Topology optimization is a powerful numerical tool in the synthesis of lightweight structures and compliant mechanisms. Compliant mechanisms present challenges for topology optimization, as they typically exhibit large displacements and rotations. Path-generation mechanisms are a class of mechanisms that are designed to follow an exact path. The characteristics of compliant mechanisms therefore exclude the validity of linear finite-element analysis to ensure the proper modeling of deformation and stresses. As stresses can exceed the limit when neglected, stress constraints are needed in the synthesis of compliant mechanisms. Both nonlinear finite-element analysis as well as the consideration of stress constraints significantly increase computational cost of topology optimization. Multiresolution topology optimization, which employs different levels of discretization for the finite-element analysis and the representation of the material distribution, allows an important reduction of computational effort. A multiresolution topology optimization methodology is proposed integrating stress constraints based on nonlinear finite-element analysis for path-generation mechanisms. Two objective formulations are used to motivate and validate this methodology: maximum-displacement mechanisms and path-generation mechanisms. The formulation of the stress constraints and their sensitivities within nonlinear finite-element analysis and multiresolution topology optimization are explained. We introduce two academic benchmark examples to demonstrate the results for each of the objective formulations. To show the practical, large-scale application of this method, results for the compliant mechanism structure of a droop-nose morphing wing concept are shown.

scholarly journals Influence of finite element mesh size on the carrying capacity analysis of single-row ball slewing bearing

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Peiyu He ◽  
Qinrong Qian ◽  
Yun Wang ◽  
Hong Liu ◽  
Erkuo Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Mesh Size ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Mesh ◽  
Heavy Load ◽  
Slewing Bearing ◽  
Maximum Contact ◽  
Slewing Bearings

Slewing bearings are widely used in industry to provide rotary support and carry heavy load. The load-carrying capacity is one of the most important features of a slewing bearing, and needs to be calculated cautiously. This paper investigates the effect of mesh size on the finite element (FE) analysis of the carrying capacity of slewing bearings. A local finite element contact model of the slewing bearing is firstly established, and verified using Hertz contact theory. The optimal mesh size of finite element model under specified loads is determined by analyzing the maximum contact stress and the contact area. The overall FE model of the slewing bearing is established and strain tests were performed to verify the FE results. The effect of mesh size on the carrying capacity of the slewing bearing is investigated by analyzing the maximum contact load, deformation, and load distribution. This study of finite element mesh size verification provides an important guidance for the accuracy and efficiency of carrying capacity of slewing bearings.

A finite element computational framework for enhanced photostrictive performance in 0–3 composites

2021 ◽  
Author(s):  
Diwakar Singh ◽  
Saurav Sharma ◽  
Saptarshi Karmakar ◽  
Rajeev Kumar ◽  
Vishal S. Chauhan ◽  
...  
Keyword(s):  
Finite Element ◽  
Computational Framework
Sign in / Sign up

Export Citation Format

Share Document