A gradient-based shape optimization scheme using an interface-enriched generalized FEM

2015 ◽  
Vol 296 ◽  
pp. 1-17 ◽  
Author(s):  
Ahmad R. Najafi ◽  
Masoud Safdari ◽  
Daniel A. Tortorelli ◽  
Philippe H. Geubelle
Keyword(s):  
Shape Optimization ◽  
Optimization Scheme ◽  
Generalized Fem ◽  
Gradient Based

OPTIMIZATION OF COMPOSITE AIRCRAFT STRUCTURES IN CONSIDERATION OF POSTBUCKLING BEHAVIOR

2010 ◽  
Vol 10 (04) ◽  
pp. 905-916 ◽  
Author(s):  
FERNASS DAOUD ◽  
MIRCEA CALOMFIRESCU
Keyword(s):  
Fiber Orientation ◽  
Load Level ◽  
Nonlinear Finite Element ◽  
Postbuckling Behavior ◽  
Optimization Scheme ◽  
Cross Sectional ◽  
Stiffened Composite Panels ◽  
Gradient Based ◽  
Element Approach ◽  
Composite Skins

An approach is presented to determine the design that minimizes the weight in consideration of the postbuckling behavior of stiffened composite panels. Since, due to computational expense, for optimization purposes a nonlinear finite element approach is not appropriate, a semianalytical approach is implemented in the EADS MAS software LAGRANGE. A gradient-based optimization scheme is employed to determine the ply thicknesses and fiber orientation of the composite skins and the cross-sectional areas of the stiffeners. Strength and stability constraints are used. Based on two examples of different complexity, weight savings are shown to be due to the fact, that skin buckling is allowed above a certain load level.

Network Redundancy: A Key Design Factor for Cooling Networks

2020 ◽  
Author(s):  
Reza Pejman ◽  
Ahmad Raeisi Najafi
Keyword(s):  
Shape Optimization ◽  
Design Optimization ◽  
Cooling Efficiency ◽  
Temperature Uniformity ◽  
Optimization Scheme ◽  
Design Factor ◽  
Numerical Examples ◽  
Optimization Framework ◽  
Hybrid Topology ◽  
Operating Constraints

Abstract Microvascular composite offers a variety of multi-functionality based on the choice of fluid flowing through the embedded microchannels. The design of the microchannel network in microvascular composites is quite challenging. Indeed, the design is often expected to have high cooling efficiency, satisfy the manufacturing and operating constraints, and also have redundancy to increase the temperature uniformity and alleviate the destructive effects of potential microchannel blockage. In this study, we present a design optimization framework to satisfy these requirements. We use the Hybrid Topology/Shape (HyTopS) optimization scheme to design a redundant blockage-tolerant cooling network. In this method, the optimizer can change the topology of the design during the shape optimization process. Being able to modify the topology of the network enables the optimizer to provide network redundancy to effectively optimize the design for blockage tolerance. We also solve several numerical examples to show the unique features of the proposed method.

Gradient-based Pareto front approximation applied to turbomachinery shape optimization

2019 ◽  
Author(s):  
Ilias Vasilopoulos ◽  
Varvara G. Asouti ◽  
Kyriakos C. Giannakoglou ◽  
Marcus Meyer
Keyword(s):  
Shape Optimization ◽  
Pareto Front ◽  
Gradient Based

Shape Optimization of a Small Bus Steering Knuckle Considering a Fatigue Load

2013 ◽  
Vol 740 ◽  
pp. 319-322 ◽  
Author(s):  
Young Choon Lee ◽  
Nam Jin Jeon ◽  
Cheol Kim ◽  
Seo Yeon Ahn ◽  
Myung Jae Cho
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Shape Optimization ◽  
Minimum Weight ◽  
Cyclic Fatigue ◽  
Fatigue Load ◽  
Element Analysis ◽  
Gradient Based

Finite element analysis was accomplished for a steering knuckle component of a small bus to see whether the static and fatigue strength requirements were satisfied or not. The knuckle was modeled with ANSYS 10-node quadratic elements. The cyclic fatigue load was applied and Soderberg criteria were applied to check the fatigue life. The knuckle structure has an infinite life (10-6 cycle) judging from the fatigue analyses. Shape optimization based on the gradient based method has been performed in order to find out the knuckle shape that has a minimum weight and satisfies the static and fatigue strength requirements. As a result of shape optimization, the weight of the steering knuckle was reduced 8%.

scholarly journals A comparative evaluation of genetic and gradient-based algorithms applied to aerodynamic optimization

2008 ◽  
pp. 103-126
Author(s):  
David W. Zingg ◽  
Marian Nemec ◽  
Thomas H. Pulliam
Keyword(s):  
Genetic Algorithm ◽  
Shape Optimization ◽  
Comparative Evaluation ◽  
Pareto Front ◽  
Optimization Problems ◽  
Aerodynamic Optimization ◽  
Design Variables ◽  
Gradient Based ◽  
Degree Of Convergence ◽  
Multipoint Optimization

A genetic algorithm is compared with a gradient-based (adjoint) algorithm in the context of several aerodynamic shape optimization problems. The examples include singlepoint and multipoint optimization problems, as well as the computation of a Pareto front. The results demonstrate that both algorithms converge reliably to the same optimum. Depending on the nature of the problem, the number of design variables, and the degree of convergence, the genetic algorithm requires from 5 to 200 times as many function evaluations as the gradientbased algorithm.

scholarly journals Shape optimization of the X0-specimen: theory, numerical simulation and experimental verification

2020 ◽  
Vol 66 (6) ◽  
pp. 1275-1291
Author(s):  
Jan Liedmann ◽  
Steffen Gerke ◽  
Franz-Joseph Barthold ◽  
Michael Brünig
Keyword(s):  
Shape Optimization ◽  
Experimental Verification ◽  
Optimization Technique ◽  
Image Correlation ◽  
Correlation Technique ◽  
Damage And Fracture ◽  
State Dependent ◽  
Gradient Based ◽  
Stress States ◽  
Critical Regions

AbstractThe paper deals with the gradient based shape optimization of the biaxial X0-specimen, which has been introduced and examined in various papers, under producibility restrictions and the related experimental verification. The original, engineering based design of the X0-specimen has been applied successfully to different loading conditions persisting the question if relevant stress states could be reached by optimizing the geometry. Specimens with the initial as well as with the two load case dependent optimized geometries have been fabricated of the aluminum alloy sheets (AlSi1MgMn; EN AW 6082-T6) and tested. The strain fields in critical regions of the specimens have been recorded by digital image correlation technique. In addition, scanning electron microscope analysis of the fracture surfaces clearly indicate the stress state dependent damage processes. Consequently, the presented gradient based optimization technique facilitated significant improvements to study the damage and fracture processes in a more purposeful way.

scholarly journals Gradient based biobjective shape optimization to improve reliability and cost of ceramic components

2019 ◽  
Vol 21 (4) ◽  
pp. 1359-1387
Author(s):  
O. T. Doganay ◽  
H. Gottschalk ◽  
C. Hahn ◽  
K. Klamroth ◽  
J. Schultes ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Ceramic Components ◽  
Gradient Based ◽  
Improve Reliability

Comparison of Gradient-Based and Genetic Algorithms for Laminar Airfoil Shape Optimization

2022 ◽  
Author(s):  
Daniel Simanowitsch ◽  
Anand Sudhi ◽  
Alexander Theiss ◽  
Camli Badrya ◽  
Stefan Hein
Keyword(s):  
Genetic Algorithms ◽  
Shape Optimization ◽  
Gradient Based
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