Generating Constructal Networks for Area-to-Point Conduction Problems Via Moving Morphable Components Approach

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Baotong Li ◽  
Chengbin Xuan ◽  
Guoguang Liu ◽  
Jun Hong
Keyword(s):  
Finite Element Method ◽  
Arbitrary Direction ◽  
Electromagnetic Bandgap ◽  
Design Algorithm ◽  
Flexible Modeling ◽  
Lagrangian Framework ◽  
Design Variables ◽  
Simulation And Experiment ◽  
Moving Morphable Components ◽  
Classical Shape

In this article, we focus on a generative design algorithm for area-to-point (AP) conduction problems in a Lagrangian framework. A physically meaningful continuous area to point path solution is generated through an adaptive growth procedure, which starts from the source point and extends spreading the whole conduction domain. This is achieved by using a set of special moving morphable components (MMCs) whose contour and skeleton are described explicitly by parameterized level-set surfaces. Unlike in the conventional methods where topology optimization was carried out in an Eulerian framework, the proposed optimizer is Lagrangian in nature, which is consistent with classical shape optimization approaches, giving great potential to reduce the total number of design variables significantly and also yielding more flexible modeling capability to control the structural feature sizes. By doing this, the growth elements are separated from the underlying finite element method (FEM) grids so that they can grow toward an arbitrary direction to form an optimized area-to-point path solution. The method is tested on an electromagnetic bandgap (EBG) power plane design example; both simulation and experiment verified the effectiveness of the proposed method.

Lagrangian Description Based Topology Optimization—A Revival of Shape Optimization

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Weisheng Zhang ◽  
Jian Zhang ◽  
Xu Guo
Keyword(s):  
Topology Optimization ◽  
Shape Optimization ◽  
Structural Design ◽  
Previous Treatment ◽  
Lagrangian Description ◽  
Design And Optimization ◽  
Lagrangian Framework ◽  
And Topology ◽  
Moving Morphable Components ◽  
Classical Shape

Unlike in the previous treatment where shape and topology optimization were carried out essentially in an Eulerian framework, the aim of the present work is to show how to perform topology optimization based on a Lagrangian framework, which is seamlessly consistent with classical shape optimization approaches, with use of a set of moving morphable components (MMCs). It is hoped that the present work may light up the revival of classical shape optimization in structural design and optimization and inspire some subsequent works along this direction. Some representative examples are also provided to illustrate the effectiveness of the proposed solution framework.

Topology Optimization Using Node-Based Smoothed Finite Element Method

2015 ◽  
Vol 07 (06) ◽  
pp. 1550085 ◽  
Author(s):  
Z. C. He ◽  
G. Y. Zhang ◽  
L. Deng ◽  
Eric Li ◽  
G. R. Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Optimization Design ◽  
Solid Mechanics ◽  
Optimality Criteria ◽  
Topology Optimization Problem ◽  
Design Variables ◽  
Smoothed Finite Element Method ◽  
Element Method

The node-based smoothed finite element method (NS-FEM) proposed recently has shown very good properties in solid mechanics, such as providing much better gradient solutions. In this paper, the topology optimization design of the continuum structures under static load is formulated on the basis of NS-FEM. As the node-based smoothing domain is the sub-unit of assembling stiffness matrix in the NS-FEM, the relative density of node-based smoothing domains serves as design variables. In this formulation, the compliance minimization is considered as an objective function, and the topology optimization model is developed using the solid isotropic material with penalization (SIMP) interpolation scheme. The topology optimization problem is then solved by the optimality criteria (OC) method. Finally, the feasibility and efficiency of the proposed method are illustrated with both 2D and 3D examples that are widely used in the topology optimization design.

Shape Opimization of Femoral Components of an Artificial Hip Prosthesis Using the Three-Dimensional P-Version Finite Element Method

2001 ◽  
Author(s):  
Masaru Higa ◽  
Ikuya Nishimura ◽  
Hiromasa Tanino ◽  
Yoshinori Mitamura
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hip Prosthesis ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Peak Stress ◽  
Cross Sectional ◽  
Design Variables ◽  
Dimensional Shape ◽  
Element Method

Abstract The three-dimensional shape optimization of cemented total hip arthroplasty (THA) was introduced in this paper. The P-version Finite Element Method (FEM) combined with an optimization procedure was used to minimize the peak stress in the bone cement near the tip of the implant. Six-design variables were used in this study. Each variable represents the dimension of the medial-lateral width and anterior-posterior width of the three levels (proximal, distal and middle) of cross sectional area of the prosthesis. The results of the design optimization showed considerable reduction in stress concentration compared to the initial design that is currently used clinically.

Optimization Methodology for Composite Stiffened Panel Based on Genetic Algorithm

2014 ◽  
Vol 952 ◽  
pp. 34-37
Author(s):  
Da Feng Jin ◽  
Zhe Liu ◽  
Zhi Rui Fan
Keyword(s):  
Genetic Algorithm ◽  
Finite Element Method ◽  
Finite Element ◽  
Design Space ◽  
Design Guidelines ◽  
Stiffened Panel ◽  
Stacking Sequence ◽  
Design Variables ◽  
Composite Stiffened Panel ◽  
Optimization Methodology

A novel optimization methodology for stiffened panel is proposed in this paper. The purpose of the optimization methodology is to improve the first buckling load of the panel which is obtained by finite element method. The stacking sequence of the stiffeners is taken as design variables. In order to ensure the manufacturability of design, the design guidelines of stacking sequence are taken into account. A DOE based on Halton Sequence makes the initial points of genetic algorithm spread more evenly in the design space of laminate parameters and consequently accelerates the search to convergence. The numerical example verifies the efficiency of this method.

Study on the Mechanical Properties of Sapphire by Numerical Simulation and Nanoindentation Technology

2009 ◽  
Vol 69-70 ◽  
pp. 103-107 ◽  
Author(s):  
Ke Hua Zhang ◽  
Dong Hui Wen ◽  
Tao Hong ◽  
Ju Long Yuan
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Plastic Region ◽  
Nanoindentation Test ◽  
Fe Modeling ◽  
The Finite Element Method ◽  
Simulation And Experiment ◽  
Abrasive Process

This paper presents a finite element (FE) modeling of the nanoindentation test of sapphire, in which the finite element method was employed to study the mechanical characteristic of sapphire under the nanoindentation process. The results demonstrated that the nanoindentation FE models were able to simulate the indentation loading-unloading curves of the sapphire. The load and unload displacement curves of the simulation and experiment results can match with each other well, and then the properties used in the simulation should be the actual properties of the sapphire. The Mises stress field distribution of the sapphire sample was calculated to reveal the alteration from elastic region to plastic region, which are useful for indentifying the ductile to brittle change in the sapphire abrasive process.

Estimating turbogenerator foundation parameters

1998 ◽  
Vol 212 (8) ◽  
pp. 653-665 ◽  
Author(s):  
M Smart ◽  
M I Friswell ◽  
A W Lees ◽  
U Prells
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
System Identification ◽  
Structural Models ◽  
Modal Testing ◽  
The Finite Element Method ◽  
Predictive Capacity ◽  
Power Stations ◽  
Simulation And Experiment ◽  
Foundation Parameters

Turbogenerators in power stations are often placed on foundation structures that are flexible over the running range of the machine and can therefore contribute to its dynamics. Established methods of obtaining structural models for these foundations, such as the finite element method or modal testing, have proved unsuccessful because of complexity or cost. Another method of foundation system identification, using the unbalance excitation applied by the rotor itself during maintenance run-downs, has previously been proposed but has not yet been experimentally verified. In this paper the necessary theory is developed and certain issues critical to the success of the estimation are examined. The method is tested in both simulation and experiment using a two-bearing rotor rig and good fits between model and measurement are obtained. The predictive capacity of the estimated models when the system is excited with a different unbalance is not as good, and it is surmised that this may be due among other things to inaccurate bearing models.

OPTIMAL DESIGN OF A 1-3 PIEZOCOMPOSITE TONPILZ TRANSDUCER BY MEANS OF THE FINITE ELEMENT METHOD

2008 ◽  
Vol 22 (11) ◽  
pp. 1087-1092 ◽  
Author(s):  
DA LIE PEI ◽  
YONGRAE ROH
Keyword(s):  
Finite Element Method ◽  
Sound Pressure ◽  
Optimization Technique ◽  
Pressure Level ◽  
Frequency Bandwidth ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Design Variables ◽  
Structural Variables ◽  
Functional Forms

Underwater Tonpilz transducer is designed with 1-3 piezocomposite materials to overcome the problems with conventional piezoceramic transducers. With the FEM, the variation of the resonance frequency, bandwidth and sound pressure of the transducer are analyzed in relation to the structural variables of the transducer. Through statistical multiple regression analysis of the results, functional forms of the transducer performance are derived in terms of design variables. By applying the constrained optimization technique, SQP-PD, to the derived functions, the optimal structure of the transducer is determined that can provide the highest sound pressure level at a given resonant frequency over a pre-determined frequency range. The validity of the optimized results is confirmed through comparison of the optimal performance with that of the FEA.

Multi-Criteria Dynamic Optimization of a Front Wheels Suspension System

2014 ◽  
Vol 656 ◽  
pp. 129-136 ◽  
Author(s):  
Cătălin Alexandru
Keyword(s):  
Dynamic Optimization ◽  
Regression Models ◽  
Suspension System ◽  
Statistical Tools ◽  
Design Algorithm ◽  
Race Car ◽  
Suspension Systems ◽  
Car Model ◽  
Design Variables ◽  
Multi Body

This work deals with the dynamic optimization of the suspension system used for the front wheels of a race car. A multi-criteria optimization is approached, intending to minimize the main oscillations of the chassis (pitch, roll and yaw). The locations (in terms of global coordinates) of some joints in the suspension system are considered as design variables for the dynamic optimization. The dynamic model of the suspension system of the front wheels, corresponding to a half-car model, is developed in MBS (Multi-Body Systems) concept, while the relationships between the design objectives and variables are determined by statistical tools, based on design of experiments and regression models. The dynamic analysis is performed in the passing over bumps regime, the substantial improvements (by comparing the behavior of the initial and optimized suspension systems) demonstrating the usefulness of the adopted optimal design algorithm.

Uncertainty optimization of dental implant based on finite element method, global sensitivity analysis and support vector regression

2018 ◽  
Vol 233 (2) ◽  
pp. 232-243 ◽  
Author(s):  
Hongyou Li ◽  
Maolin Shi ◽  
Xiaomei Liu ◽  
Yuying Shi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Support Vector Regression ◽  
Dental Implant ◽  
Support Vector ◽  
Manufacturing Cost ◽  
Bone Interface ◽  
Design Variables ◽  
Uncertainty Optimization ◽  
Element Method

In this work, an uncertainty optimization approach for dental implant is proposed to reduce the stress at implant–bone interface. Finite element method is utilized to calculate the stress at implant–bone interface, and support vector regression is used to replace finite element method to ease the computational cost. Deterministic optimization based on support vector regression is conducted, which demonstrates that the method using support vector regression replacing finite element method in dental implant optimization is efficient and reliable. Global sensitivity analysis based on support vector regression is used to assign different uncertainties (manufacturing errors) to different design variables to save the manufacturing cost. Two popular uncertainty optimization methods, k-sigma method and interval method, are used for the uncertainty optimization of dental implant. The results indicate that the stress at implant–bone interface is reduced greatly considering the uncertainties in design variables with the manufacturing cost increasing a little. This approach can be promoted to other types of bio-implants.

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