scholarly journals Reliable Shape Optimization of Structures Subjected to Transient Dynamic Loading Using Genetic Algorithms

2005 ◽  
Vol 12 (6) ◽  
pp. 407-424 ◽  
Author(s):  
Sabyasachi Chand ◽  
Anjan Dutta
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Genetic Algorithms ◽  
Shape Optimization ◽  
Analysis Tool ◽  
Time Step ◽  
Transient Dynamic ◽  
Boundary Definition ◽  
Automatic Mesh ◽  
Shape Changes

This paper presents a reliable method of solution of two dimensional shape optimization problems subjected to transient dynamic loads using Genetic Algorithms. Boundary curves undergoing shape changes have been represented by B-splines. Automatic mesh generation and adaptive finite element analysis modules are integrated with Genetic algorithm code to carry out the shape optimization. Both space and time discretization errors are evaluated and appropriate finite element mesh and time step values as obtained iteratively are adopted for accurate dynamic response. Two demonstration problems have been solved, which show convergence to the optimal solution with number of generations. The boundary curve undergoing shape optimization shows smooth shape changes. The combinations of automatic mesh generator with proper boundary definition capabilities, analysis tool with error estimation and Genetic algorithm as optimization engine have been observed to behave as a satisfactory shape optimization environment to deal with real engineering problems.

scholarly journals Framework for the Shape Optimization of Aerodynamic Profiles Using Genetic Algorithms

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
D. López ◽  
C. Angulo ◽  
I. Fernández de Bustos ◽  
V. García
Keyword(s):  
Fluid Dynamics ◽  
Genetic Algorithm ◽  
Computational Fluid Dynamics ◽  
Genetic Algorithms ◽  
Shape Optimization ◽  
Computational Fluid Dynamics Cfd

This study developed a framework for the shape optimization of aerodynamics profiles using computational fluid dynamics (CFD) and genetic algorithms. A genetic algorithm code and a commercial CFD code were integrated to develop a CFD shape optimization tool. The results obtained demonstrated the effectiveness of the developed tool. The shape optimization of airfoils was studied using different strategies to demonstrate the capacity of this tool with different GA parameter combinations.

scholarly journals Truss’ topology and shape optimization by genetic algorithms

2021 ◽  
Vol 47 ◽  
Author(s):  
Dmitrij Šešok ◽  
Paulius Ragauskas
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Shape Optimization ◽  
Optimization Problem ◽  
Numerical Solutions ◽  
Search Algorithm ◽  
Truss Topology ◽  
Modified Genetic Algorithm ◽  
Topology And Shape Optimization ◽  
System Characteristics

In the paper the global optimization problem of truss systems is studied.  The genetic algorithms are employed for the optimization. As the objective function the structure mass is treated; the constraints include equilibrium, local stability and other requirements.  All the truss system characteristics needed for genetic algorithm are obtained via finite element solution. Topology optimization of truss system is performed using original modified genetic algorithm, while the shape optimization – using ordinary genetic algorithm. Numerical solutions are presented. The obtained solutions are compared with global extremes obtained using full search algorithm.  All the numerical examples are solved using original software.

scholarly journals Mixed genetic algorithm for optimization of trusses

2008 ◽  
Vol 48 ◽  
Author(s):  
Dmitrij Šešok
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Finite Elements ◽  
Shape Optimization ◽  
Objective Function ◽  
Objective Function Value ◽  
Finite Elements Method ◽  
Topology And Shape Optimization ◽  
Mixed Genetic Algorithm

In this paper two strategies of optimization are compared: sequential and synchronous topology and shape optimization of trusses. Genetic algorithms are used for optimization. A task of optimization of truss withtwelve possible nodes is solved. Finite elements method is used to calculate an objective function value. Software used in calculations was created by the author.

scholarly journals Shape Optimization of a Wooden Baseball Bat Using Parametric Modeling and Genetic Algorithms

AI ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 381-393
Author(s):  
Mohammad Sadegh Mazloomi ◽  
Philip D. Evans
Keyword(s):  
Finite Element ◽  
Genetic Algorithms ◽  
Shape Optimization ◽  
Parametric Modeling ◽  
Performance Criteria ◽  
Optimization Approach ◽  
Modeling And Optimization ◽  
Nodal Points ◽  
Subtractive Manufacturing ◽  
Baseball Bats

Baseball is a popular and very lucrative bat-and-ball sport that uses a wooden bat to score runs. We hypothesize that new design features for baseball bats will emerge from their shape optimization using parametric modeling and genetic algorithms. We converge the location of two points on bats made from maple (Acer sp.) and ash (Fraxinus sp.) wood that are associated with increased velocity of a ball rebounding off a bat: vibrational nodal points and the center of percussion (COP). Our modeling and optimization approach was able to reduce the distance between the nodal points and COP from 166.0 mm to 52.1 mm. This change was similar in both wood species and resulted from changes to the geometry of the bat, specifically shifting of the mass of the bat toward the center of the barrel and removing mass from the very end of the barrel. We conclude that the combination of parametric finite element modeling and optimization using genetic algorithms is a powerful tool for exploring virtual designs for baseball bats that are based on performance criteria and suggest that our designs could be realized in practice using subtractive manufacturing technology.

Shape Optimization of a Trumpet-Tipped LVAD Inflow Cannula to Reduce Blood Damage Using a Genetic Algorithm

2019 ◽  
Author(s):  
Christopher J. Nassau ◽  
Ramesh K. Agarwal
Keyword(s):  
Genetic Algorithm ◽  
Shape Optimization ◽  
Left Ventricular ◽  
Analysis Tool ◽  
Ventricular Assist ◽  
Blood Damage ◽  
Medical Device Design ◽  
The Status ◽  
Inflow Cannula ◽  
Radiological Health

Abstract Use of computational fluid dynamics (CFD) in the field of blood-contacting medical device design and analysis has been growing in recent years. For example, the U.S. Food and Drug Administration (FDA) Center of Devices and Radiological Health (CDRH) has accelerated interest in industry and academia with nozzle and blood pump benchmarks to uncover best practices and to hopefully elevate the status of CFD to be applied as a safety analysis tool for medical devices. One area, not discussed as often as the pure simulation is the design optimization of hemodynamic devices. A systematic shape “optimization” should be distinguished from a simple “design improvement” by performing many flow field computations and design iterations to improve performance. In this paper, the shape optimization of a trumpet-tipped inflow cannula is presented using a single-objective genetic algorithm (GA) to minimize the blood damage. Many varying accounts in the literature have pointed to the advantages of the trumpet-tipped left ventricular assist device (LVAD) cannula for low blood damage and uniform velocity distribution with little to no backflow when compared to other shapes such as blunt, beveled and caged cannulas.

Shape Optimization of NURBS Modeled 3D C-Frames Using Hybrid Genetic Algorithm

2002 ◽  
Author(s):  
Hesham A. Hegazi ◽  
Ashraf O. Nassef ◽  
Sayed M. Metwalli
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Shape Optimization ◽  
Cross Sections ◽  
Beam Theory ◽  
Direct Search ◽  
Search Method ◽  
Optimum Shape ◽  
Curved Beam ◽  
Real Coded Genetic Algorithms

The present paper introduces a new methodology for designing machine element shapes. The element is represented using non-uniform rational B-Spline (NURBS) in order to give it a form of shape flexibility. A special form of genetic algorithms known as real-coded genetic algorithms is used to conduct the search for the design objectives. Shape optimization of 3D C-frames are used as an application of the proposed methodology. The design parameters of these frames include the dimensions of their cross-sections, which should be chosen to withstand the applied loads and minimize the element’s overall weight. In a further development, the hybridization of different optimization methods has been used to find the optimum shape of the element. Real coded genetic algorithm is used as a random search method, while Nelder-Mead is used as a direct search method, where the result of the genetic algorithm search is used as the starting point of direct search. The results showed that the use of Nelder-Mead with Real coded Genetic Algorithms has been very significant in improving the optimum shape of a solid 3D C-frames subjected to a combined tension and bending stresses. The hybrid optimization method could be extended to more complex shape optimization problems. For the purpose of analysis, curved beam theory is applied on local cross-sections on the NURBS surface. A finite elements analysis was conducted on SDRC-IDEAS for verifying the results obtained using the curved beam theory.

Topological optimization of a bumper beam via the messy genetic algorithm

1998 ◽  
Vol 212 (2) ◽  
pp. 133-143 ◽  
Author(s):  
G Duponcheele ◽  
D G Tilley
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Shape Optimization ◽  
Industrial Application ◽  
Optimization Problems ◽  
Topological Optimization ◽  
Shape Grammars ◽  
Bumper Beam ◽  
Derivative Information

This paper introduces a technique for certain types of topological shape optimization problems, called variable primary and full grammars, which are derived from shape grammars. An industrial application is used as an example based on the optimization of an automotive structural bumper beam. The optimizer, the messy genetic algorithm, a technique more powerful than traditional genetic algorithms, does not use any derivative information on the evolution of the shape, but only simple evaluations. This technique produces interesting new designs for bumper beams, although they are not globally optimal. These new designs have moved from crenellations to more complex topologies.

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