Download or read book Multiscale Design of Nonlinear Materials Using a Shape Optimization Scheme Based on an Interface enriched GFEM written by Ahmad Raeisi Najafi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiscale Optimization And Materials Design written by Jun Yan and published by World Scientific. This book was released on 2020-12-29 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents a set of novel, efficient and systematic concurrent multiscale optimization methods by considering the distribution of the material in macro-scale and the unit-cell configuration design in micro-scale simultaneously. Different from the traditional optimization method that is performed in a single scale, the proposed methods could generate a great deal of improvements in structural performance through the multiscale structure-material concurrent optimum design.The proposed theory and methods are related to statics, dynamics, thermoelastics and the coupling of different physical fields. Therefore, it provides a comprehensive designing scheme when multiple factors are taken into account. For example, the designing scheme can have a great significance on enhancing the structural performances under coupled multi-physical fields, such as load bearing capacity, vibration resistance ability, and safety under thermal stress and so on.Several numerical examples are highlighted in this unique volume based on practical engineering applications. The examples collectively demonstrate drastically improved designs featuring excellent unit-cell configuration and highly regular macroscale material distribution in a variety of industrial applications.
Download or read book Integrated Design of Multiscale Multifunctional Materials and Products written by David L. McDowell and published by Butterworth-Heinemann. This book was released on 2009-09-30 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated Design of Multiscale, Multifunctional Materials and Products is the first of its type to consider not only design of materials, but concurrent design of materials and products. In other words, materials are not just selected on the basis of properties, but the composition and/or microstructure iw designed to satisfy specific ranged sets of performance requirements. This book presents the motivation for pursuing concurrent design of materials and products, thoroughly discussing the details of multiscale modeling and multilevel robust design and provides details of the design methods/strategies along with selected examples of designing material attributes for specified system performance. It is intended as a monograph to serve as a foundational reference for instructors of courses at the senior and introductory graduate level in departments of materials science and engineering, mechanical engineering, aerospace engineering and civil engineering who are interested in next generation systems-based design of materials. First of its kind to consider not only design of materials, but concurrent design of materials and products Treatment of uncertainty via robust design of materials Integrates the "materials by design approach" of Olson/Ques Tek LLC with the "materials selection" approach of Ashby/Granta Distinquishes the processes of concurrent design of materials and products as an overall systems design problem from the field of multiscale modeling Systematic mathematical algorithms and methods are introduced for robust design of materials, rather than ad hoc heuristics--it is oriented towards a true systems approach to design of materials and products
Download or read book Multiscale Modelling and Optimisation of Materials and Structures written by Tadeusz Burczynski and published by John Wiley & Sons. This book was released on 2022-05-19 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addresses the very topical, crucial and original subject of parameter identification and optimization within multiscale modeling methods Multiscale Modelling and Optimization of Materials and Structures presents an important and challenging area of research that enables the design of new materials and structures with better quality, strength and performance parameters as well as the creation of reliable models that take into account structural, material and topological properties at different scales. The authors’ approach is four-fold; 1) the basic principles of micro and nano scale modeling techniques; 2) the connection of micro and/or nano scale models with macro simulation software; 3) optimization development in the framework of multiscale engineering and the solution of identification problems; 4) the computer science techniques used in this model and advice for scientists interested in developing their own models and software for multiscale analysis and optimization. The authors present several approaches such as the bridging and homogenization methods, as well as the general formulation of complex optimization and identification problems in multiscale modelling. They apply global optimization algorithms based on robust bioinspired algorithms, proposing parallel and multi-subpopulation approaches in order to speed-up computations, and discuss several numerical examples of multiscale modeling, optimization and identification of composite and functionally graded engineering materials and bone tissues. Multiscale Modelling and Optimization of Materials and Structures is thereby a valuable source of information for young scientists and students looking to develop their own models, write their own computer programs and implement them into simulation systems. Describes micro and nano scale models developed by the authors along with case studies of analysis and optimization Discusses the problems of computing costs, efficiency of information transfer, effective use of the computer memory and several other aspects of development of multiscale models Includes real physical, chemical and experimental studies with modern experimental techniques Provides a valuable source of information for young scientists and students looking to develop their own models, write their own computer programs, and implement them into simulation systems.
Download or read book Uncertainty Quantification in Multiscale Materials Modeling written by Yan Wang and published by Woodhead Publishing Limited. This book was released on 2020-03-12 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainty Quantification in Multiscale Materials Modeling provides a complete overview of uncertainty quantification (UQ) in computational materials science. It provides practical tools and methods along with examples of their application to problems in materials modeling. UQ methods are applied to various multiscale models ranging from the nanoscale to macroscale. This book presents a thorough synthesis of the state-of-the-art in UQ methods for materials modeling, including Bayesian inference, surrogate modeling, random fields, interval analysis, and sensitivity analysis, providing insight into the unique characteristics of models framed at each scale, as well as common issues in modeling across scales.
Download or read book Shape Optimization And Optimal Design written by John Cagnol and published by CRC Press. This book was released on 2017-08-02 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents developments and advances in modelling passive and active control systems governed by partial differential equations. It emphasizes shape analysis, optimal shape design, controllability, nonlinear boundary control, and stabilization. The authors include essential data on exact boundary controllability of thermoelastic plates with variable transmission coefficients.
Download or read book Parametric and Topology Optimization for Multidisciplinary Design Using a Decomposition Method to Address Nonlinear Boundary Conditions written by Tianliang Yu and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlinearities frequently appear in the field couplings and/or the boundary conditions in the multidisciplinary problems that are encountered in aerospace system design. Compared to linear analysis, nonlinear analysis involves higher computational costs to determine solutions and gradients. Efficient strategies are critical for multidisciplinary design optimization (MDO) problems, especially for those with nonlinearities. In this thesis, an MDO problem is solved in a hierarchical architecture that comprises two subproblems of optimization, namely discipline-level optimization, and design-level optimization. In the discipline-level optimization, a linearization method is proposed to decompose a multidisciplinary system with nonlinear boundary conditions into multiple subsystems, which can be modeled using systems of coupled linear equations. The multidisciplinary analysis problem the becomes equivalent to an optimization problem that minimizes the discrepancy between the shared boundary variables of each subsystem. In the design-level optimization, both gradient-based and heuristic algorithms can be used with respect to the global design variables subject to design constraints. Two diverse case problems with boundary nonlinearities, which are representative of aeronautical and astronautical applications, are investigated to validate the proposed method. The first case problem is a topology optimization for the design of a contact-aided heat valve structure for spacecraft passive thermal control. The thermal control is implemented based on variable thermal contact resistance (TCR), which depends on the contact pressure at an interface caused by material thermal expansion. The thermal contact resistance is a nonlinear function of the contact pressure; thus, the problem can be modeled as a thermo-mechanical coupled system with nonlinear boundary conditions. The optimization objective is maximizing the performance of the heat valve, which operates to minimize temperature variations of spacecraft electronic devices under different thermal loads. First, a one-dimensional model is developed to validate the feasibility of the thermal control mechanism. Second, a finite element method is formulated to address thermal conduction and thermal expansion of isotropic materials in a design domain of rectangular shape for the two-dimensional model. A topology optimization scheme based on the solid isotropic material with penalization (SIMP) approach is developed to explore the optimal material distribution. Using the proposed linearization method, the nonlinear thermal boundary conditions are transformed into Dirichlet boundary conditions. Then the coupled system can be solved by minimizing the difference of contact pressures computed from the thermal and mechanical systems in the discipline-level optimization. The method of moving asymptotes (MMA) is used to update design variables in the design-level topology optimization. Optimal topologies and corresponding temperature distributions are obtained using input parameters and constraints representing realistic situations. For the "hot" case, in which a uniform heat flux of 50,000W/m2 is input to the top surface, the top surface temperature remains lower than the maximum allowable temperature, 305K, for all optimal designs with material volume fraction higher than 0.2. For both the hot and cold cases, the top surface temperature never drops below the minimum allowable temperature, 275K. Results also show that the convergence of the analysis algorithm is sensitive to the initial guess of the Dirichlet boundary conditions. Although the algorithm lacks robustness for special cases, the linearization method and topology optimization scheme are generally effective for design optimization of the contact-aided heat valve structure. The second case problem is a parametric optimization for the design of a bimorph piezoelectric-driven synthetic jet actuator (SJA). SJAs are zero-net-mass-flux actuators which create non-zero-net momentum flux via periodic suction and ejection of fluid through an orifice. Resonant piezoelectric-diaphragm-type SJAs have been studied recently, yet the modeling remains a challenge due to the complexities and nonlinearities associated with both electro-elastic and fluid-structure couplings. The ultimate design objective is maximizing the time-averaged jet momentum. Lumped-element modeling has shown good capability to predict jet momentum but lacks accuracy for high-amplitude nonlinear response. Finite element methods yield accurate predictions but are computationally costly for design and optimization purposes. In this thesis, a low-order model is developed to capture electro-elastic and acoustic-structure couplings with adequate accuracy. In the initial approach, by matching the diaphragm mechanical resonance frequency with the cavity acoustic resonance frequency, the performance of optimal SJA design is determined by optimizing the structural proxies of the jet, such as blocking pressure and free displacement. An electro-elastic assumed-modes model is implemented to study the transverse motion of the piezoelectric diaphragms. In the improved approach, the performance of the jet is studied directly by coupling the electro-elastic model to a simplified cavity acoustic model, which is a one-degree-of-freedom spring-mass system. The linearity of the system is determined by the damping force associated with jet velocity. If the damping force is linear with velocity, the system is linear, and vice versa. For the case of a nonlinear jet damping force, a linearization method is implemented in a way that approximates the nonlinear periodic responses by the superposition of finite numbers of linear responses at odd harmonics of the driving frequency using truncated Fourier series. Therefore, the nonlinear viscous damping boundary condition can be transformed into Neumann boundary conditions at each odd harmonic frequency. The response of the nonlinear electro-elastic-acoustic coupled system can be solved using systems of linear equations at each of these frequencies. Then the discipline-level optimization minimizes the difference of the viscous damping forces obtained from the initial guess of the boundary conditions and the solutions of the coupled system equations. In the design-level optimization, a parametric optimization scheme based on a particle swarm optimization approach maximizes the time-averaged jet momentum. Optimal configurations based on the optimization results are obtained based on both linear and nonlinear models. For the linear model, the optimal design has a short-circuit resonance frequency of 1332 Hz, and an acoustic resonance frequency of 551 Hz. For the nonlinear model, the optimal design has a short-circuit resonance frequency of 1523 Hz, and an acoustic resonance frequency of 725 Hz. Although the optimal designs are different using linear and nonlinear models, both results show similar patterns, among them that the structural resonance frequency does not match but exceeds the acoustic resonance frequency. Using the nonlinear model, the best performance is found in the optimal configuration using PZT8, which has a driving frequency of 1270 Hz, a jet velocity of 390 m/s, a jet momentum flux of 4.79 m4/s2 driven at 10% of the material's coercive field. The linearization method and parametric optimization scheme are generally effective for the design optimization of the piezoelectric-driven synthetic jet actuators. Both case studies generally validate the feasibility of the proposed method for practical aerospace system designs.
Download or read book Multiscale Materials Modeling written by Siegfried Schmauder and published by Walter de Gruyter GmbH & Co KG. This book was released on 2016-08-22 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents current spatial and temporal multiscaling approaches of materials modeling. Recent results demonstrate the deduction of macroscopic properties at the device and component level by simulating structures and materials sequentially on atomic, micro- and mesostructural scales. The book covers precipitation strengthening and fracture processes in metallic alloys, materials that exhibit ferroelectric and magnetoelectric properties as well as biological, metal-ceramic and polymer composites. The progress which has been achieved documents the current state of art in multiscale materials modelling (MMM) on the route to full multi-scaling. Contents: Part I: Multi-time-scale and multi-length-scale simulations of precipitation and strengthening effects Linking nanoscale and macroscale Multiscale simulations on the coarsening of Cu-rich precipitates in α-Fe using kinetic Monte Carlo, Molecular Dynamics, and Phase-Field simulations Multiscale modeling predictions of age hardening curves in Al-Cu alloys Kinetic Monte Carlo modeling of shear-coupled motion of grain boundaries Product Properties of a two-phase magneto-electric composite Part II: Multiscale simulations of plastic deformation and fracture Niobium/alumina bicrystal interface fracture Atomistically informed crystal plasticity model for body-centred cubic iron FE2AT ・ finite element informed atomistic simulations Multiscale fatigue crack growth modeling for welded stiffened panels Molecular dynamics study on low temperature brittleness in tungsten single crystals Multi scale cellular automata and finite element based model for cold deformation and annealing of a ferritic-pearlitic microstructure Multiscale simulation of the mechanical behavior of nanoparticle-modified polyamide composites Part III: Multiscale simulations of biological and bio-inspired materials, bio-sensors and composites Multiscale Modeling of Nano-Biosensors Finite strain compressive behaviour of CNT/epoxy nanocomposites Peptide・zinc oxide interaction
Download or read book Multiscale Modelling of Advanced Materials written by Runa Kumari and published by Springer Nature. This book was released on 2020-02-08 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume covers the recent advances and research on the modeling and simulation of materials. The primary aim is to take the reader through the mathematical analysis to the theories of electricity and magnetism using multiscale modelling, covering a variety of numerical methods such as finite difference time domain (FDTD), finite element method (FEM) and method of moments. The book also introduces the multiscale Green’s function (GF) method for static and dynamic modelling and simulation results of modern advanced nanomaterials, particularly the two-dimensional (2D) materials. This book will be of interest to researchers and industry professionals working on advanced materials.
Download or read book Integrated Design of Multiscale Multifunctional Materials and Products written by Jitesh Panchal and published by . This book was released on 2010 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated Design of Multiscale, Multifunctional Materials and Products is the first of its type to consider not only design of materials, but concurrent design of materials and products. In other words, materials are not just selected on the basis of properties, but the composition and/or microstructure iw designed to satisfy specific ranged sets of performance requirements. This book presents the motivation for pursuing concurrent design of materials and products, thoroughly discussing the details of multiscale modeling and multilevel robust design and provides details of the design methods/strategies along with selected examples of designing material attributes for specified system performance. It is intended as a monograph to serve as a foundational reference for instructors of courses at the senior and introductory graduate level in departments of materials science and engineering, mechanical engineering, aerospace engineering and civil engineering who are interested in next generation systems-based design of materials. Key Features: * First of its kind to consider not only design of materials, but concurrent design of materials and products. * Treatment of uncertainty via robust design of materials * Integrates the "materials by design approach" of Olson/Ques Tek LLC with the "materials selection" approach of Ashby/Granta * Distinquishes the processes of concurrent design of materials and products as an overall systems design problem from the field of multiscale modeling * Systematic mathematical algorithms and methods are introduced for robust design of materials, rather than ad hoc heuristics--it is oriented towards a true systems approach to design of materials and products
Download or read book A Multiscale Nonlinear Modeling Framework Enabling the Design and Analysis of Composite Materials and Structures written by Brett A. Bednarcyk and published by BiblioGov. This book was released on 2013-07 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A framework for the multiscale design and analysis of composite materials and structures is presented. The ImMAC software suite, developed at NASA Glenn Research Center, embeds efficient, nonlinear micromechanics capabilities within higher scale structural analysis methods such as finite element analysis. The result is an integrated, multiscale tool that relates global loading to the constituent scale, captures nonlinearities at this scale, and homogenizes local nonlinearities to predict their effects at the structural scale. Example applications of the multiscale framework are presented for the stochastic progressive failure of a SiC/Ti composite tensile specimen and the effects of microstructural variations on the nonlinear response of woven polymer matrix composites.
Download or read book Shape Design Sensitivity Analysis and Optimization Using the Boundary Element Method written by Zhiye Zhao and published by Springer. This book was released on 1991 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Shape Optimization and Free Boundaries written by Michel C. Delfour and published by Springer. This book was released on 2014-04-21 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape optimization deals with problems where the design or control variable is no longer a vector of parameters or functions but the shape of a geometric domain. They include engineering applications to shape and structural optimization, but also original applications to image segmentation, control theory, stabilization of membranes and plates by boundary variations, etc. Free and moving boundary problems arise in an impressingly wide range of new and challenging applications to change of phase. The class of problems which are amenable to this approach can arise from such diverse disciplines as combustion, biological growth, reactive geological flows in porous media, solidification, fluid dynamics, electrochemical machining, etc. The objective and orginality of this NATO-ASI was to bring together theories and examples from shape optimization, free and moving boundary problems, and materials with microstructure which are fundamental to static and dynamic domain and boundary problems.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shape Optimization Problems written by Hideyuki Azegami and published by Springer Nature. This book was released on 2020-09-30 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides theories on non-parametric shape optimization problems, systematically keeping in mind readers with an engineering background. Non-parametric shape optimization problems are defined as problems of finding the shapes of domains in which boundary value problems of partial differential equations are defined. In these problems, optimum shapes are obtained from an arbitrary form without any geometrical parameters previously assigned. In particular, problems in which the optimum shape is sought by making a hole in domain are called topology optimization problems. Moreover, a problem in which the optimum shape is obtained based on domain variation is referred to as a shape optimization problem of domain variation type, or a shape optimization problem in a limited sense. Software has been developed to solve these problems, and it is being used to seek practical optimum shapes. However, there are no books explaining such theories beginning with their foundations. The structure of the book is shown in the Preface. The theorems are built up using mathematical results. Therefore, a mathematical style is introduced, consisting of definitions and theorems to summarize the key points. This method of expression is advanced as provable facts are clearly shown. If something to be investigated is contained in the framework of mathematics, setting up a theory using theorems prepared by great mathematicians is thought to be an extremely effective approach. However, mathematics attempts to heighten the level of abstraction in order to understand many things in a unified fashion. This characteristic may baffle readers with an engineering background. Hence in this book, an attempt has been made to provide explanations in engineering terms, with examples from mechanics, after accurately denoting the provable facts using definitions and theorems.
Download or read book Crystal Plasticity Finite Element Methods written by Franz Roters and published by John Wiley & Sons. This book was released on 2011-08-04 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the leading experts in computational materials science, this handy reference concisely reviews the most important aspects of plasticity modeling: constitutive laws, phase transformations, texture methods, continuum approaches and damage mechanisms. As a result, it provides the knowledge needed to avoid failures in critical systems udner mechanical load. With its various application examples to micro- and macrostructure mechanics, this is an invaluable resource for mechanical engineers as well as for researchers wanting to improve on this method and extend its outreach.
Download or read book Practical Aspects of Computational Chemistry written by Jerzy Leszczynski and published by Springer Science & Business Media. This book was released on 2009-10-03 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Practical Aspects of Computational Chemistry" presents contributions on a range of aspects of Computational Chemistry applied to a variety of research fields. The chapters focus on recent theoretical developments which have been used to investigate structures and properties of large systems with minimal computational resources. Studies include those in the gas phase, various solvents, various aspects of computational multiscale modeling, Monte Carlo simulations, chirality, the multiple minima problem for protein folding, the nature of binding in different species and dihydrogen bonds, carbon nanotubes and hydrogen storage, adsorption and decomposition of organophosphorus compounds, X-ray crystallography, proton transfer, structure-activity relationships, a description of the REACH programs of the European Union for chemical regulatory purposes, reactions of nucleic acid bases with endogenous and exogenous reactive oxygen species and different aspects of nucleic acid bases, base pairs and base tetrads.
