Structural Design Applications of Mathematical Programming Techniques

Structural Design Applications of Mathematical Programming Techniques

Author: North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Structures and Materials Panel

Publisher:

Published: 1971

Total Pages: 212

ISBN-13:

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The document describes the present state of development of the use of mathematical programming techniques in the optimum design of aerospace and similar structures. Although optimization with respect to cost is considered when possible, the main emphasis is on the minimization of weight, due to the overwhelming importance of this parameter in aerospace applications, and also due to the fact that it is one of the few merit functions that can be defined with reasonable precision. The use of mathematical programming techniques in the selection of materials is also discussed to the limited extent meaningful at the present time. (Author).


Structural Optimization

Structural Optimization

Author: William R. Spillers

Publisher: Springer Science & Business Media

Published: 2009-06-10

Total Pages: 304

ISBN-13: 0387958657

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Structural Optimization is intended to supplement the engineer’s box of analysis and design tools making optimization as commonplace as the finite element method in the engineering workplace. It begins with an introduction to structural optimization and the methods of nonlinear programming such as Lagrange multipliers, Kuhn-Tucker conditions, and calculus of variations. It then discusses solution methods for optimization problems such as the classic method of linear programming which leads to the method of sequential linear programming. It then proposes using sequential linear programming together with the incremental equations of structures as a general method for structural optimization. It is furthermore intended to give the engineer an overview of the field of structural optimization.


Mathematical Programming Methods in Structural Plasticity

Mathematical Programming Methods in Structural Plasticity

Author: D. Lloyd Smith

Publisher: Springer

Published: 2014-05-04

Total Pages: 433

ISBN-13: 3709126185

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Civil engineering structures tend to be fabricated from materials that respond elastically at normal levels of loading. Most such materials, however, would exhibit a marked and ductile inelasticity if the structure were overloaded by accident or by some improbable but naturally occuring phenomeon. Indeed, the very presence of such ductility constitutes an important safety provision for large-scale constructions where human life is at risk. In the comprehensive evaluation of safety in structural design, it is therefore unrealistic not to consider the effects of ductility. This book sets out to show that the bringing together of the theory and methods of mathematical programming with the mathematical theory of plasticity furnishes a model which has a unifying theoretical nature and is entirely representative of observed structural behaviour. The contents of the book provide a review of the relevant aspects of mathematical programming and plasticity theory, together with a detailed presentation of the most interesting and potentially useful applications in both framed and continuum structures: ultimate strength and elastoplastic deformability; shakedown and practical upper bounds on deformation measures; evolutive dynamic response; large displacements and instability; stochastic and fuzzy programming for representing uncertainty in ultimate strength calculations. Besides providing a ready fund of computational algorithms, mathematical programming invests applications in mechanics with a refined mathematical formalism, rich in fundamental theorems, which often gives addi- tional insight into known results and occasionally lead to new ones. In addition to its obvious practical utility, the educational value of the material thoroughly befits a university discipline.


Software Systems for Structural Optimization

Software Systems for Structural Optimization

Author: H.R. Hörnlein

Publisher: Birkhäuser

Published: 2013-03-07

Total Pages: 287

ISBN-13: 3034885539

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Herbert Hornlein, Klaus Schittkowski The finite element method (FEM) has been used successfully for many years to simulate and analyse mechanical structural problems. The results are accepted or rejected by means of comparison of state variables (stresses, displacements, natural frequencies etc.) and user requirements. In further analyses the design variables will be updated until the user specifications are met and the design is feasible. This is the primary aim of the design process. On this set of feasible designs, the additional requirement given by an objective function (e.g. weight, stiffness, efficiency, etc.) defines the structural optimization problem. In recent years more and more finite element based analysis systems were ex tended and offer now optimization modules. They proceed from the design model as defined for structural analysis, to perform an internal adaption of design pa rameters based on formal mathematical methods. Despite of many common features, there are significant differences in the selected optimization strategy, the current implementation and the numerical results.


Topology Optimization

Topology Optimization

Author: Martin Philip Bendsoe

Publisher: Springer Science & Business Media

Published: 2013-04-17

Total Pages: 381

ISBN-13: 3662050862

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The topology optimization method solves the basic enginee- ring problem of distributing a limited amount of material in a design space. The first edition of this book has become the standard text on optimal design which is concerned with the optimization of structural topology, shape and material. This edition, has been substantially revised and updated to reflect progress made in modelling and computational procedures. It also encompasses a comprehensive and unified description of the state-of-the-art of the so-called material distribution method, based on the use of mathematical programming and finite elements. Applications treated include not only structures but also materials and MEMS.


Shape Design Sensitivity Analysis and Optimization Using the Boundary Element Method

Shape Design Sensitivity Analysis and Optimization Using the Boundary Element Method

Author: Zhiye Zhao

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 203

ISBN-13: 3642843824

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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.