Dynamic Models for Structural Plasticity


Book Description

Our topic is irreversible or plastic deformation of structural elements composed of relatively thin ductile materials. These deformations are commonly used in sheet metal forming operations to produce lightweight parts of any particular shape. In another context, this type of plastic deformation is described as impact damage in the case of structural components involved in collision. Here we are concerned with mechanics of both static and dynamic deformation processes. The purpose is to use typical material properties and structural characteristics to calculate the deformation for certain types of load; in particular to find the final deflection and shape of the deformed structure and to illustrate how the development of this final shape depends on the constitutive model used to represent the material behavior. The major issue to be addressed is which structural and constitutive properties are important for calculating response to either static or brief but intense dynamic loads. Furthermore, how do the results of various constitutive models compare with observed behavior.




Structural Plasticity


Book Description

Limit and shakedown analysis for structures can provide a very useful tool for design and analysis of engineering structures. "Structural Plasticity - Limit, Shakedown and Dynamic Plastic Analyses of Structure" provides more general solutions of limit and shakedown analysis for structures by using a unified strength theory. A series of solutions of plates from circular, annular plates to rhombus plates and square plates, rotating discs and cylinders, pressure vessels are presented. These results encompass the Tresca-Mohr-Coulomb solution of structure as special cases. The unified solution, which cannot be obtained by using a single criterion, is suitable to more materials and structures. Maohong Yu is professor of Department of Civil Engineering at Xi'an Jiaotong University, China. He has authored 12 books including "Unified Strength Theory and Its Applications" and "Generalized Plasticity".




The Rewiring Brain


Book Description

The adult brain is not as hard-wired as traditionally thought. By modifying their small- or large-scale morphology, neurons can make new synaptic connections or break existing ones (structural plasticity). Structural changes accompany memory formation and learning, and are induced by neurogenesis, neurodegeneration and brain injury such as stroke. Exploring the role of structural plasticity in the brain can be greatly assisted by mathematical and computational models, as they enable us to bridge the gap between system-level dynamics and lower level cellular and molecular processes. However, most traditional neural network models have fixed neuronal morphologies and a static connectivity pattern, with plasticity merely arising from changes in the strength of existing synapses (synaptic plasticity). In The Rewiring Brain, the editors bring together for the first time contemporary modeling studies that investigate the implications of structural plasticity for brain function and pathology. Starting with an experimental background on structural plasticity in the adult brain, the book covers computational studies on homeostatic structural plasticity, the impact of structural plasticity on cognition and cortical connectivity, the interaction between synaptic and structural plasticity, neurogenesis-related structural plasticity, and structural plasticity in neurological disorders. Structural plasticity adds a whole new dimension to brain plasticity, and The Rewiring Brain shows how computational approaches may help to gain a better understanding of the full adaptive potential of the adult brain. The book is written for both computational and experimental neuroscientists. - Reviews the current state of knowledge of structural plasticity in the adult brain - Gives a comprehensive overview of computational studies on structural plasticity - Provides insights into the potential driving forces of structural plasticity and the functional implications of structural plasticity for learning and memory - Serves as inspiration for developing novel treatment strategies for stimulating functional repair after brain damage




Unified Plasticity for Engineering Applications


Book Description

Considerably simplified models of macroscopic material behavior, such as the idealization for metals of elastic-time independent plastic response with a yield (onset) criterion, have served the engineering profession well for many years. They are still basic to the design and analysis of most structural applications. In the need to use materials more effectively, there are circumstances where those traditional models are not adequate, and constitutive laws that are more physically realistic have to be employed. This is especially relevant to conditions where the inherent time dependence of inelastic deformations, referred to as "viscoplasticity", is pronounced such as at elevated temperatures and for high strain rates. Unified theories of elastic-viscoplastic material behavior, which are primarily applicable for metals and metallic alloys, combine all aspects of inelastic response into a set of time dependent equations with a single inelastic strain rate variable. For such theories, creep under constant stress, stress relaxation under constant strain, and stress-strain relations at constant rates are each special cases of a general formulation. Those equations mayor may not include a yield criterion, but models which do not separate a fully elastic region from the overall response could be considered "unified" in a more general sense. The theories have reached a level of development and maturity where they are being used in a number of sophisticated engineering applications. However, they have not yet become a standard method of material representation for general engineering practice.




Modelling of Mechanical Systems: Structural Elements


Book Description

The modelling of mechanical systems provides engineers and students with the methods to model and understand mechanical systems by using both mathematical and computer-based tools. Written by an eminent authority in the field, this is the second of four volumes which provide engineers with a comprehensive resource on this cornerstone mechanical engineering subject. Dealing with continuous systems, this book covers solid mechanics, beams, plates and shells. In a clear style and with a practical rather than theoretical approach, it shows how to model continuous systems in order to study vibration modes, motion and forces. Appendices give useful primers on aspects of the mathematics introduced in the book. Other volumes in the series cover discrete systems, fluid-structure interaction and flow-induced vibration.*Axisa is a world authority in the modelling of systems*Comprehensive coverage of mathematical techniques used to perform computer-based analytical studies and numerical simulations*A key reference for mechanical engineers, researchers and graduate students in this cornerstone subject




Advances in the Analysis and Design of Marine Structures


Book Description

Advances in the Analysis and Design of Marine Structures is a collection of papers presented at MARSTRUCT 2023, the 9th International Conference on Marine Structures, held in Gothenburg, Sweden, 3-5 April 2023. The conference was organised by the Division of Marine Technology, Department of Mechanics and Maritime Sciences at Chalmers University of Technology, in Gothenburg, Sweden. The MARSTRUCT Conference series deals with Ship and Offshore Structures, addressing topics in the fields of: Methods and tools for loads and load effects Methods and tools for strength assessment Experimental analysis of structures Materials and fabrication of structures Methods and tools for structural design and optimization Structural reliability, safety, and environmental protection The MARSTRUCT conferences series of started in Glasgow, UK in 2007, the second event of the series took place in Lisbon, Portugal in March 2009, the third in Hamburg, Germany in March 2011, the fourth in Espoo, Finland in March 2013, the fifth in Southampton, UK in March 2015, the sixth in Lisbon, Portugal in May 2017, the seventh in Dubrovnik, Croatia in May 2019, and the eighth event in Trondheim, Norway in June 2021. Advances in the Analysis and Design of Marine Structures is essential reading for academics, engineers and all professionals involved in the design of marine and offshore structures. The Proceedings in Marine Technology and Ocean Engineering series is devoted to the publication of proceedings of peer-reviewed international conferences dealing with various aspects of ‘Marine Technology and Ocean Engineering’. The Series includes the proceedings of the following conferences: the International Maritime Association of the Mediterranean (IMAM) Conferences, the Marine Structures (MARSTRUCT) Conferences, the Renewable Energies Offshore (RENEW) Conferences and the Maritime Technology (MARTECH) Conferences. The ‘Marine Technology and Ocean Engineering’ series is also open to new conferences that cover topics on the sustainable exploration and exploitation of marine resources in various fields, such as maritime transport and ports, usage of the ocean including coastal areas, nautical activities, the exploration and exploitation of mineral resources, the protection of the marine environment and its resources, and risk analysis, safety and reliability. The aim of the series is to stimulate advanced education and training through the wide dissemination of the results of scientific research.




Anatomy and Plasticity in Large-Scale Brain Models


Book Description

Supercomputing facilities are becoming increasingly available for simulating activity dynamics in large-scale neuronal networks. On today's most advanced supercomputers, networks with up to a billion of neurons can be readily simulated. However, building biologically realistic, full-scale brain models requires more than just a huge number of neurons. In addition to network size, the detailed local and global anatomy of neuronal connections is of crucial importance. Moreover, anatomical connectivity is not fixed, but can rewire throughout life (structural plasticity)—an aspect that is missing in most current network models, in which plasticity is confined to changes in synaptic strength (synaptic plasticity). The papers in this Ebook, which may broadly be divided into three themes, aim to bring together high-performance computing with recent experimental and computational research in neuroanatomy. In the first theme (fiber connectivity), new methods are described for measuring and data-basing microscopic and macroscopic connectivity. In the second theme (structural plasticity), novel models are introduced that incorporate morphological plasticity and rewiring of anatomical connections. In the third theme (large-scale simulations), simulations of large-scale neuronal networks are presented with an emphasis on anatomical detail and plasticity mechanisms. Together, the articles in this Ebook make the reader aware of the methods and models by which large-scale brain networks running on supercomputers can be extended to include anatomical detail and plasticity.




Energy Absorption of Structures and Materials


Book Description

This important study focuses on the way in which structures and materials can be best designed to absorb kinetic energy in a controllable and predictable manner. Understanding of energy absorption of structures and materials is important in calculating the damage to structures caused by accidental collision, assessing the residual strength of structures after initial damage and in designing packaging to protect its contents in the event of impact. Whilst a great deal of recent research has taken place into the energy absorption behaviour of structures and materials and significant progress has been made, this knowledge is diffuse and widely scattered. This book offers a synthesis of the most recent developments and forms a detailed and comprehensive view of the area. It is an essential reference for all engineers concerned with materials engineering in relation to the theory of plasticity, structural mechanics and impact dynamics. - Important new study of energy absorption of engineering structures and materials - Shows how they can be designed to withstand sudden loading in a safe, controllable and predictable way - Illuminating case studies back up the theoretical analysis




Structures Under Shock and Impact XII


Book Description

Of interest to engineers from civil, military, nuclear, offshore, aeronautical, transportation and other backgrounds, this book contains the proceedings of a well-established conference on the subject that was first held in 1989. Topics covered include: Impact and Blast Loading Characteristics; Protection of Structures from Blast Loads; Energy Absorbing Issues; Structural Crashworthiness; Hazard Mitigation and Assessment; Behaviour of Steel Structures; Behaviour of Structural Concrete; Material Response to High Rate Loading; Seismic Engineering Applications; Interaction Between Computational and Experimental Results; Innovative Materials and Material Systems; Fluid Structure Interaction.The shock and impact behaviour of structures presents challenges to researchers not only because it has obvious time-dependent aspects, but also because it is difficult to specify the external dynamic loading characteristics and to obtain the full dynamic properties of materials. It is crucial that we find ways to share the contributions and understanding that are developing from various theoretical, numerical and experimental studies, as well as investigations into material properties under dynamic loading conditions. This book helps to meet that need.




Generalized Continua as Models for Classical and Advanced Materials


Book Description

This volume is devoted to an actual topic which is the focus world-wide of various research groups. It contains contributions describing the material behavior on different scales, new existence and uniqueness theorems, the formulation of constitutive equations for advanced materials. The main emphasis of the contributions is directed on the following items - Modelling and simulation of natural and artificial materials with significant microstructure, - Generalized continua as a result of multi-scale models, - Multi-field actions on materials resulting in generalized material models, - Theories including higher gradients, and - Comparison with discrete modelling approaches