Dynamic Loading and Design of Structures


Book Description

Until now, information on the dynamic loading of structures has been widely scattered. No other book has examined the different types of loading in a comprehensive and systematic manner, and looked at their signficance in the design process. The book begins with a survey of the probabilistic background to all forms of loads, which is particularly important to dynamic loads, and then looks at the main types in turn: wind, earthquake, wave, blast and impact loading. The relevant code provisions (Eurocode and UBC American) are detailed and a number of examples are used to illustrate the principles. A final section covers the analysis for dynamic loading, drawing out the concepts underlying the treatment of all dynamic loads, and the corresponding modelling techniques. Throughout there is a focus on the modelling of structures, rather than on classical structural dynamics.







Introduction to Optimization of Structures


Book Description

This is an exposition of the theory, techniques, and the basic formulation of structural optimization problems. The author considers applications of design optimization criteria involving strength, rigidity, stability and weight. Analytic and numerical techniques are introduced for research in optimal shapes and internal configurations of deformable bodies and structures. Problems of the optimal design of beams, systems of rods, plates and shells, are studied in detail. With regard to applications, this work is oriented towards solutions of real problems, such as reduction of the volume or weight of the material, and improvement of mechanical properties of structures. This book is written for readers specializing in applied mechanics, applied mathematics, and numerical analysis."




Optimal Structural Design under Stability Constraints


Book Description

The first optimal design problem for an elastic column subject to buckling was formulated by Lagrange over 200 years ago. However, rapid development of structural optimization under stability constraints occurred only in the last twenty years. In numerous optimal structural design problems the stability phenomenon becomes one of the most important factors, particularly for slender and thin-walled elements of aerospace structures, ships, precision machines, tall buildings etc. In engineering practice stability constraints appear more often than it might be expected; even when designing a simple beam of constant width and variable depth, the width - if regarded as a design variable - is finally determined by a stability constraint (lateral stability). Mathematically, optimal structural design under stability constraints usually leads to optimization with respect to eigenvalues, but some cases fall even beyond this type of problems. A total of over 70 books has been devoted to structural optimization as yet, but none of them has treated stability constraints in a sufficiently broad and comprehensive manner. The purpose of the present book is to fill this gap. The contents include a discussion of the basic structural stability and structural optimization problems and the pertinent solution methods, followed by a systematic review of solutions obtained for columns, arches, bar systems, plates, shells and thin-walled bars. A unified approach based on Pontryagin's maximum principle is employed inasmuch as possible, at least to problems of columns, arches and plates. Parametric optimization is discussed as well.




Computer Aided Optimal Design: Structural and Mechanical Systems


Book Description

This book contains the edited version of lectures and selected papers presented at the NATO ADVANCED STUDY INSTITUTE ON COMPUTER AIDED OPTIMAL DESIGN: Structural and Mechanical Systems, held in Tr6ia, Portugal, 29th June to 11th July 1986, and organized by CEMUL -Center of Mechanics and Materials of the Technical University of Lisbon. The Institute was attended by 120 participants from 21 countries, including leading scientists and engineers from universities, research institutions and industry, and Ph.D. students. Some participants presented invited and contributed papers during the Institute and almost all participated actively in discussions on scientific aspects during the Institute. The Advanced Study Institute provided a forum for interaction among eminent scientists and engineers from different schools of thought and young reseachers. The Institute addressed the foundations and current state of the art of essential techniques related to computer aided optimal design of structural and mechanical systems, namely: Vari ational and Finite Element Methods in Optimal Design, Numerical Optimization Techniques, Design Sensitivity Analysis, Shape Optimal Design, Adaptive Finite Element Methods in Shape Optimization, CAD Technology, Software Development Techniques, Integrated Computer Aided Design and Knowledge Based Systems. Special topics of growing importance were also pre sented.







Recent Advances in Optimal Structural Design


Book Description

Sponsored by the Technical Committee on Structural Design of the Technical Administrative Committee on Analysis and Computation of the Technical Activities Division of the Structural Engineering Institute of ASCE. This report documents the dramatic new developments in the field of structural optimization over the last two decades. Changes in both computational techniques and applications can be seen by developments in computational methods and solution algorithms, the role of optimization during the various stages of structural design, and the stochastic nature of design in relation to structural optimization. Topics include: Ømethods for discrete variable structural optimization; Ødecomposition methods in structural optimization; Østate of the art on the use of genetic algorithms in design of steel structures; Øconceptual design optimization of engineering structures; Øtopology and geometry optimization of trusses and frames; Øevolutionary structural optimization; Ødesign and optimization of semi-rigid framed structures; Øoptimized performance-based design for buildings; Ømulti-objective optimum design of seismic-resistant structures; and Øreliability- and cost-oriented optimal bridge maintenance planning. The book concludes with an extensive bibliography of journal papers on structural optimization published between 1987 and 1999.




Structural Design via Optimality Criteria


Book Description

"During the last two decades, research on structural optimization became increasingly concerned with two aspects: the application of general numeri cal methods of optimization to structural design of complex real structures, and the analytical derivation of necessary and sufficient conditions for the optimality of broad classes of comparatively simple and more or less ideal ized structures. Both kinds of research are important: the first for obvious reasons; the second, because it furnishes information that is useful in testing the validity, accuracy and convergence of numerical methods and in assess ing the efficiency of practical designs. {raquo} (Prager and Rozvany, 1977a) The unexpected death of William Prager in March 1980 marked, in a sense, the end of an era in structural mechanics, but his legacy of ideas will re main a source of inspiration for generations of researchers to come. Since his nominal retirement in the early seventies, Professor and Mrs. Prager lived in Savognin, an isolated alpine village and ski resort surrounded by some of Switzerland's highest mountains. It was there that the author's close as sociation with Prager developed through annual pilgrimages from Australia and lengthy discussions which pivoted on Prager's favourite topic of struc tural optimization. These exchanges took place in the picturesque setting of Graubunden, on the terrace of an alpine restaurant overlooking snow-capped peaks, on ski-lifts or mountain walks, or during evening meals in the cosy hotels of Savognin, Parsonz and Riom.




EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization


Book Description

The papers in this volume focus on the following topics: design optimization and inverse problems, numerical optimization techniques,efficient analysis and reanalysis techniques, sensitivity analysis and industrial applications. The conference EngOpt brings together engineers, applied mathematicians and computer scientists working on research, development and practical application of optimization methods in all engineering disciplines and applied sciences.




Creep in Structures


Book Description

There is a tradition to organize IUTAM Symposia "Creep in Structures" every ten years: the first Symposium was organized by N.J. Hoff in Stan ford (1960), the second one by J. Hult in Goteborg (1970), and the third one by A.R.S. Ponter in Leicester (1980). The fourth Symposium in Cracow, September 1990, gathered 123 par ticipants from 21 countries and reflected rapid development of the theory, experimental research and structural applications of creep and viscoplas ticity, including damage and rupture. Indeed, the scope of the Sympo sium was broad, maybe even too broad, but it was kept according to the tradition. Probably the chairman of "Creep in Structures V" in the year 2000 (if organized at all) will be forced to confine the scope substantially. Participation in the Symposium was reserved for invited participants, suggested by members of the Scientific Committee. Total number of sug gestions was very large and the response - unexpectedly high. Apart from several papers rejected, as being out of scope, over 100 papers were accepted for presentation. A somewhat unconventional way of presenta tion was introduced to provide ample time for fruitful and well prepared discussions: besides general lectures (30 minutes each), all the remain ing papers were presented as short introductory lectures (10 minutes) followed by a I-hour poster discussion with the authors and then by a general discussion. Such an approach made it possible to present general ideas orally, and then to discuss all the papers through and through.