Investigations in Structural Optimization of Nonlinear Problems Using the Finite Element Method PDF Download

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Languages : en
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Author: Makoto Ohsaki
Publisher: Springer Science & Business Media
ISBN: 0387681841
Category : Technology & Engineering
Languages : en
Pages : 276

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This book focuses on the optimization of a geometrically-nonlinear structure under stability constraint. It presents a deep insight into optimization-based and computer-assisted stability design of discrete structures. Coverage combines design sensitivity analysis developed in structural optimization and imperfection-sensitivity analysis developed in stability analysis.

Author: R. A. Gellatly
Publisher:
ISBN:
Category : Aeronautics, Military
Languages : en
Pages : 102

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To overcome problems arising from the rigorous representation of stress constraints in structural optimization, the use of the force method is demonstrated. The force method of finite element analysis is used to transform a stress-constrained redundant structure into a stress and displacement constrained determinate structure for the purposes of optimization. The resulting problem is non-linear, but the use of a linear programming stage is effective in providing a rapid convergence on the optimum design in many cases. Problems which hitherto required many iterations to converge are now solvable in only one or two steps. The rate of constraint numbers versus numbers of variables is investigated analytically using a 22-bar truss problem as an example. The vital key in optimization technology is identified as the identification of active constraints. The incorporation of displacement constraints into the optimization program is also presented. Examples of problems solved by this approach are included. Discussion of difficulties encountered in the development work also provides indicators for future areas of research. (Author).

Author: Xiaodong Huang
Publisher: John Wiley & Sons
ISBN: 9780470689479
Category : Technology & Engineering
Languages : en
Pages : 240

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Evolutionary Topology Optimization of Continuum Structures treads new ground with a comprehensive study on the techniques and applications of evolutionary structural optimization (ESO) and its later version bi-directional ESO (BESO) methods. Since the ESO method was first introduced by Xie and Steven in 1992 and the publication of their well-known book Evolutionary Structural Optimization in 1997, there have been significant improvements in the techniques as well as important practical applications. The authors present these developments, illustrated by numerous interesting and detailed examples. They clearly demonstrate that the evolutionary structural optimization method is an effective approach capable of solving a wide range of topology optimization problems, including structures with geometrical and material nonlinearities, energy absorbing devices, periodical structures, bridges and buildings. Presents latest developments and applications in this increasingly popular & maturing optimization approach for engineers and architects; Authored by leading researchers in the field who have been working in the area of ESO and BESO developments since their conception; Includes a number of test problems for students as well as a chapter of case studies that includes several recent practical projects in which the authors have been involved; Accompanied by a website housing ESO/BESO computer programs at http://www.wiley.com/go/huang and test examples, as well as a chapter within the book giving a description and step-by-step instruction on how to use the software package BESO2D. Evolutionary Topology Optimization of Continuum Structures will appeal to researchers and graduate students working in structural design and optimization, and will also be of interest to civil and structural engineers, architects and mechanical engineers involved in creating innovative and efficient structures.

Author: G.I.N. Rozvany
Publisher: Springer
ISBN: 3709127882
Category : Technology & Engineering
Languages : en
Pages : 493

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Shape and layout optimization represent some of the most useful but also most difficult classes of problems in structural design, which have been investigated in detail only during the last few years. Shape optimization is concerned with the optimal shape of boundaries of continua or of interfaces between two materials in composites. Layout optimization deals with the simultaneous optimization of the topology, geometry and cross-sectional sizes of structural systems. In spite of its complextiy, layout optimization is a very rewarding task, because it results in much greater savings than the optimization of cross-sectional sizes only. Because of their important role in shape and layout optimization, the book also covers in detail new optimality criteria methods, which are capable of handling many thousand design variables and active design contraints. Shape and layout optimization is becoming an indispensable tool in the design of aeroplanes, space structures, cars, ships, building and civil engineering structures, power stations, chemical plants, artificial organs, sporting equipment, and all other solid systems where stresses and deformations play an important role.

Author: Zhiye Zhao
Publisher: Springer Science & Business Media
ISBN: 3642843824
Category : Technology & Engineering
Languages : en
Pages : 203

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This book investigates the various aspects of shape optimization of two dimensional continuum structures, including shape design sensitivity analysis, structural analysis using the boundary element method (BEM), and shape optimization implementation. The book begins by reviewing the developments of shape optimization, followed by the presentation of the mathematical programming methods for solving optimization problems. The basic theory of the BEM is presented which will be employed later on as the numerical tool to provide the structural responses and the shape design sensitivities. The key issue of shape optimization, the shape design sensitivity analy sis, is fully investigated. A general formulation of stress sensitivity using the continuum approach is presented. The difficulty of the modelling of the ad joint problem is studied, and two approaches are presented for the modelling of the adjoint problem. The first approach uses distributed loads to smooth the concentrated adjoint loads, and the second approach employs the singu larity subtraction method to remove the singular boundary displacements and tractions from the BEM equation. A novel finite difference based approach to shape design sensitivity is pre sented, which overcomes the two drawbacks of the conventional finite difference method. This approach has the advantage of being simple in concept, and eas ier implementation. A shape optimization program for two-dimensional continuum structures is developed, including structural analysis using the BEM, shape design sensitiv ity analysis, mathematical programming, and the design boundary modelling.

Author: Z. Waszczyszyn
Publisher: Elsevier
ISBN: 1483290557
Category : Technology & Engineering
Languages : en
Pages : 483

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This book is the consequence of research undertaken by the authors in the field of advanced problems of structural mechanics. Stability analysis of structures comes under this area because of the complex models and computational methods needed for analysis. In the mid seventies, a joint effort began between a group of researchers and teachers of the Department of Civil Engineering and Computer Center of the Cracow University of Technology. One of the important results of the collaboration has been this publication.

Author: Jesper Christensen
Publisher: Butterworth-Heinemann
ISBN: 0124173098
Category : Mathematics
Languages : en
Pages : 488

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Nonlinear Optimization of Vehicle Safety Structures: Modeling of Structures Subjected to Large Deformations provides a cutting-edge overview of the latest optimization methods for vehicle structural design. The book focuses on large deformation structural optimization algorithms and applications, covering the basic principles of modern day topology optimization and comparing the benefits and flaws of different algorithms in use. The complications of non-linear optimization are highlighted, along with the shortcomings of recently proposed algorithms. Using industry relevant case studies, users will how optimization software can be used to address challenging vehicle safety structure problems and how to explore the limitations of the approaches given. The authors draw on research work with the likes of MIRA, Jaguar Land Rover and Tata Motors European Technology Centre as part of multi-million pound European funded research projects, emphasizing the industry applications of recent advances. The book is intended for crash engineers, restraints system engineers and vehicle dynamics engineers, as well as other mechanical, automotive and aerospace engineers, researchers and students with a structural focus. - Focuses on non-linear, large deformation structural optimization problems relating to vehicle safety - Discusses the limitations of different algorithms in use and offers guidance on best practice approaches through the use of relevant case studies - Author's present research from the cutting-edge of the industry, including research from leading European automotive companies and organizations - Uses industry relevant case studies, allowing users to understand how optimization software can be used to address challenging vehicle safety structure problems and how to explore the limitations of the approaches given

Author: Raphael T. Haftka
Publisher: Springer
ISBN: 9789024729500
Category : Science
Languages : en
Pages : 288

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Author: J. Herskovits
Publisher: Springer Science & Business Media
ISBN: 9401104530
Category : Technology & Engineering
Languages : en
Pages : 508

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Book Description
Advances in Structural Optimization presents the techniques for a wide set of applications, ranging from the problems of size and shape optimization (historically the first to be studied) to topology and material optimization. Structural models are considered that use both discrete and finite elements. Structural materials can be classical or new. Emerging methods are also addressed, such as automatic differentiation, intelligent structures optimization, integration of structural optimization in concurrent engineering environments, and multidisciplinary optimization. For researchers and designers in industries such as aerospace, automotive, mechanical, civil, nuclear, naval and offshore. A reference book for advanced undergraduate or graduate courses on structural optimization and optimum design.