A Study of Implicit and Explicit Methods for Design Sensitivity Analysis of Nonlinear Dynamic Systems
Author: Abhijit Dutta
Publisher:
Published: 1996
Total Pages: 710
ISBN-13:
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Author: Abhijit Dutta
Publisher:
Published: 1996
Total Pages: 710
ISBN-13:
DOWNLOAD EBOOKAuthor: K. K. Choi
Publisher: Springer Science & Business Media
Published: 2006-12-22
Total Pages: 336
ISBN-13: 0387273069
DOWNLOAD EBOOKExtensive numerical methods for computing design sensitivity are included in the text for practical application and software development. The numerical method allows integration of CAD-FEA-DSA software tools, so that design optimization can be carried out using CAD geometric models instead of FEA models. This capability allows integration of CAD-CAE-CAM so that optimized designs can be manufactured effectively.
Author: Cornelius T. Leondes
Publisher: CRC Press
Published: 1999-02-22
Total Pages: 284
ISBN-13: 9789056996444
DOWNLOAD EBOOKFormulation of an optimal dynamic structural system design problem requires identification of design variables that describe the structural system, a cost function that needs to be minimized, and performance and safety constraints for the system. The formulation of the problem depends upon the type of application and objectives to be achieved, i.e., the shape, the sizing, or topology design problem. Specific design variable definition, cost of function and constraints are dictated by the application. This volume is a comprehensive treatment of the general methods involved in this broadly fundamental problem and provides essential techniques in specific but pervasive structural dynamic systems elements and their optimization.
Author:
Publisher:
Published: 2008
Total Pages: 868
ISBN-13:
DOWNLOAD EBOOKAuthor: Daniel Anthony Tortorelli
Publisher:
Published: 1988
Total Pages: 260
ISBN-13:
DOWNLOAD EBOOKTwo adjoint formulations are developed for the design sensitivity analysis of linear and nonlinear dynamic thermoelastic systems. The variation of a general design functional is expressed in explicit form with respect to variations of the design quantities, i.e. material properties, applied loads, prescribed boundary conditions, initial conditions, and shape. The design functional is expressed in terms of these explicit quantities and the implicit response variables: displacement, temperature, stress, strain, heat flux vector, temperature gradient, reaction forces, and reaction surface flux. The convolution is employed, in lieu of the time mappings used in other approaches to account for transient response. The design sensitivities for dynamic thermoelastic, nonlinear uncoupled dynamic thermoelastic problems are presented here for the first time. The use of the convolution for sensitivity analysis is also presented here for the first time. By formulating these sensitivities, numerical optimization algorithms currently used for elastostatic structure redesign, can be applied to nonlinear dynamic thermoelastic systems. Sensitivities for linear elastodynamic and dynamic thermoelastic problems are derived by incorporating the reciprocal theorem between a variation of the real design and an adjoint system. The Lagrange multiplier method is utilized to formulate sensitivities for nonlinear uncoupled dynamic thermoelastic problems. These formulations may also be specialized for linear and nonlinear transient conduction problems. The finite element method is used to demonstrate the numerical implementation of the formulations. Shape sensitivities are evaluated and compared with finite difference calculations to validate the results. A numerical optimization algorithm is combined with the sensitivity analyses to redesign the geometry of a mold in a casting problem and the shape of structure whose response is governed by a nonlinear quasi-static thermoelastic system.
Author: Lisa G. Stanley
Publisher: SIAM
Published: 2002-01-01
Total Pages: 155
ISBN-13: 0898715245
DOWNLOAD EBOOKIllustrates some of the important issues inherent in using the sensitivity equation method for PDEs.
Author: American Institute of Aeronautics and Astronautics
Publisher:
Published: 2006
Total Pages: 1380
ISBN-13:
DOWNLOAD EBOOKAuthor: N. C. Barman
Publisher:
Published: 1981
Total Pages: 180
ISBN-13:
DOWNLOAD EBOOKIn this report, the technical objective is the derivation of a systematic and unified theory and organization of a corresponding general computer program for the design of constrained dynamic systems by judicious selection of the most suitable methods from the following branches of mathematics and mechanics: (a) Optimization Methods, (b) Rigid Body Mechanics, (c) Numerical Integration Methods, and (d) Matrix Manipulation Methods. Accordingly, a method of formulating and automatically integrating the equations of motion and design sensitivity adjoint equations for general constrained dynamic systems is presented. Design sensitivity analysis is carried out using a state-space method that has previously been used for design optimization of linear structural systems. Application of efficient sparse matrix computational methods is shown to be suitable for both dynamic and design sensitivity analyses and for interactive strained system is treated with three degrees of freedom. Algebraic equations prescribing constraints between various bodies are then written and a Lagrangian formulation is used to write the dynamical equations of motion for each body of the system. A stiff predictor-corrector numerical integration (GEAR) algorithm is used for numerical integration of mixed systems of nonlinear differential equations of motion and algebraic equations of constraint (together with spring-damper relations and other user-supplied equations).
Author: Michael Kleiber
Publisher:
Published: 1997-05-12
Total Pages: 432
ISBN-13:
DOWNLOAD EBOOKThere are various methods for the analysis and design of bodies subject to static and dynamic loadings in structural and solid mechanics. Sensitivity analysis is concerned with the relationship between parameters, describing the structure under consideration and the function describing the response of that structure under loading conditions. This book addresses the finite element computational techniques typical of sensitivity analysis for solid mechanics systems with any nonlinearity. It is an attempt to combine theoretical modelling techniques with effective computer implementation: besides the theory many suitable finite element codes have been developed by the authors and used for computing examples discussed in the text.
Author: Dan M. Frangopol
Publisher:
Published: 1997
Total Pages: 240
ISBN-13:
DOWNLOAD EBOOKThe 16 peer-reviewed papers describe recent developments in the US, Denmark, Italy, and Japan. They focus on the critical importance of concepts and methods of optimization both in designing new facilities and in replacing, repairing, and retrofitting existing ones. The topics include the optimal allocation of resources for preventive interventions on bridges, life-cycle cost analysis with natural hazard risk for water systems, and symptom-based reliability and health monitoring. Addressed to both academics and practitioners. Annotation copyrighted by Book News, Inc., Portland, OR