Dynamic Mechanical Behaviors and Constitutive Model of Roller Compacted Concrete


Book Description

This book systematically illustrates the dynamic mechanical behaviors and discusses the fundamentals of the constitutive modeling of roller-compacted concrete (RCC), influenced by the construction technique and mix design. Four typical problems are analyzed using laboratory tests, numerical simulation and theoretical analysis, i.e., to illustrate the special dynamic mechanical behaviors of RCC, to reveal the dynamic size-dependence of mechanical properties, to discuss the aggregate size effect on dynamic mechanical properties, and to modify the dynamic constitutive model for RCC. Generally, the constitutive modeling of RCC needs a comprehensive understanding of dynamic size-dependence and aggregate size effect of concrete that coupled with the strain-rate sensitivity. So that, readers can master the modified dynamic constitutive model of RCC to analyze and solve the problems in blast-resistance analysis and protective design of RCC dams. This book can be used as a postgraduate textbook for civil and hydraulic engineering in colleges and universities, and as an elective course for senior undergraduates. It can also be used as a reference for relevant professional scientific researchers and engineers in field of protective design of concrete structures.




Characterization and Modeling of the Ratcheting Behavior of the Ferritic-Martensitic Steel P91


Book Description

In this work, the ratcheting-behavior of 9%Cr-1%Mo ferritic-martensitic steel is studied with uniaxial cyclic loading. To describe the ratcheting-behavior of this steel, a visco-plastic constitutive model with consideration of cyclic softening of Reduced Activation Ferritic Martensitic steels is further modified, based on the analysis of back stress.




Long and Deep Tunnels


Book Description

The design and construction of “long and deep” tunnels, i.e. tunnels under mountains, characterised by either considerable length and/or overburden, represent a considerable challenge. The scope of this book is not to instruct how to design and construct such tunnels but to share a method to identify the potential hazards related to the process of designing and constructing long and deep tunnels, to produce a relevant comprehensive analysis and listing, to quantify the probability and consequences, and to design proper mitigation measures and countermeasures. The design, developed using probabilistic methods, is verified during execution by means of the so called Plan for Advance of the Tunnel (PAT) method, which allows adapting the design and control parameters of the future stretches of the tunnel to the results of the stretches already finished, using the monitoring data base. Numerous criteria are given to identify the key parameters, necessary for the PAT procedure. Best practices of excavation management with the help of real time monitoring and control are also provided. Furthermore cost and time evaluation systems are analysed. Finally, contractual aspects related to construction by contract are investigated, for best development and application of models more appropriate for tunnelling-construction contracts. The work will be of interest to practising engineers, designers, consultants and students in mining, underground, tunnelling, transportation and construction engineering, as well as to foundation and geological engineers, urban planners/developers and architects.







Constitutive Modelling and Failure Prediction for Silicone Adhesives in Façade Design


Book Description

This book provides readers with an elementary understanding of the material behavior of structural silicones in façades. Based on extensive experimental investigations on a transparent structural silicone adhesive (TSSA), the material behavior, failure, and microscopic effects such as stress whitening, cavitation failure, and the Mullins effect are analyzed. In turn, novel hyperelastic material models are developed to account for nonlinear material behavior under arbitrary deformations. The development of a volumetric hyperelastic model makes it possible for the first time to approximate the structural behavior of TSSA under constrained tensile load and cavitation. The material models discussed here were implemented in a finite element code for validation, and their quality was confirmed by three-dimensional numerical simulations, in which an additional stretch-based failure criterion was evaluated for failure prediction. The numerical studies are in good agreement with the experimental results.










Mechanosensitivity of the Nervous System


Book Description

This book presents the latest findings in mechanosensitivity of the nervous system. The nervous system stands out from a number of tissues because besides reacting to the mechanical stress it is transmitting its own response to other organs and tissues, which are located downstream of its signaling pathway. For this reason any type of mechanical stimulation of the nervous system, which is capable of triggering a physiological response, has high scientific and practical significance, since it allows its use beyond a particular experimental model anywhere where it is contributing to a particular pathological condition. This book is a unique collection of reviews outlining the current knowledge and the future developments in this rapidly growing field. Currently, investigations of the effects of mechanical stress on the nervous system are focused on several issues. The majority of studies investigate the effects of mechanical stimulation on mechanosensitive channels, as its primary target and interactive agent, and aim on description of downstream intracellular signaling pathways together with addressing general issues of biomechanics of the nervous system. Knowledge of biomechanics, and mechanisms, which underlie it on organism, organ, tissue and cellular level, is necessary for understanding of the normal functioning of living organisms and allows to predict changes which arise due to alterations of their environment, and possibly will allow to develop new methods of artificial intervention. The book brings up the problem closer to the experts in related medical and biological sciences as well as practicing doctors besides just presenting the latest achievements in the field.