Modeling and Mechanics of Granular and Porous Materials

Modeling and Mechanics of Granular and Porous Materials

Soils are complex materials: they have a particulate structure and fluids can seep through pores, mechanically interacting with the solid skeleton. Moreover, at a microscopic level, the behaviour of the solid skeleton is highly unstable. External loadings are in fact taken by grain chains which are continuously destroyed and rebuilt. Many issues of modeling, even of the physical details of the phenomena, remain open, even obscure; de Gennes listed them not long ago in a critical review. However, despite physical complexities, soil mechanics has developed on the assumption that a soil can be seen as a continuum, or better yet as a medium obtained by the superposition of two and sometimes three con and the other fluids, which occupy the same portion of tinua, one solid space. Furthermore, relatively simple and robust constitutive laws were adopted to describe the stress-strain behaviour and the interaction between the solid and the fluid continua. The contrast between the intrinsic nature of soil and the simplistic engi neering approach is self-evident. When trying to describe more and more sophisticated phenomena (static liquefaction, strain localisation, cyclic mo bility, effects of diagenesis and weathering, ..... ), the nalve description of soil must be abandoned or, at least, improved. Higher order continua, incrementally non-linear laws, micromechanical considerations must be taken into account. A new world was opened, where basic mathematical questions (such as the choice of the best tools to model phenomena and the proof of the well-posedness of the consequent problems) could be addressed.

Mechanics of Granular Materials

New Models and Constitutive Relations

Mechanics of Granular Materials

Studies in Applied Mechanics, Volume 7: Mechanics of Granular Materials: New Models and Constitutive Relations provides information pertinent to the fundamental aspects of the mechanics of granular materials. This book presents the theoretical and experimental studies of quasi-static deformations of granular materials. Organized into 30 chapters, this volume begins with an overview of the results on the description of a macroscopic stress measure and measures of the fabric of granular masses that support external loads through frictional contact. This text then introduces some quantities for the macroscopic description of mechanical and graphical characteristics of granular materials. Other chapters consider particle rolling, which appears to be a major microscopic deformation mechanism when interparticle friction is large. This book discusses as well the stress-induced anisotropy of granular materials that have initially strong anisotropic fabric. The final chapter deals with the interpretation of linear instabilities of voidage disturbances in fluidized beds. This book is a valuable resource for scientists, theoreticians, and experimentalists.

Dynamic Response of Granular and Porous Materials under Large and Catastrophic Deformations

Dynamic Response of Granular and Porous Materials under Large and Catastrophic Deformations

A "Sonderforschungsbereich" (SFB) is a programme of the "Deutsche For schungsgemeinschaft" to financially support a concentrated research effort of a number of scientists located principally at one University, Research La boratory or a number of these situated in close proximity to one another so that active interaction among individual scientists is easily possible. Such SFB are devoted to a topic, in our case "Deformation and Failure in Metallic and Granular M aterialK' , and financing is based on a peer reviewed proposal for three (now four) years with the intention of several prolongations after evaluation of intermediate progress and continuation reports. An SFB is terminated in general by a formal workshop, in which the state of the art of the achieved results is presented in oral or I and poster communications to which also guests are invited with whom the individual project investigators may have collaborated. Moreover, a research report in book form is produced in which a number of articles from these lectures are selected and collected, which present those research results that withstood a rigorous reviewing pro cess (with generally two or three referees). The theme deformation and failure of materials is presented here in two volumes of the Lecture Notes in Applied and Computational Mechanics by Springer Verlag, and the present volume is devoted to granular and porous continua. The complementary volume (Lecture Notes in Applied and Com putational Mechanics, vol. 10, Eds. K. HUTTER & H.

Shock Phenomena in Granular and Porous Materials

Shock Phenomena in Granular and Porous Materials

Granular forms of common materials such as metals and ceramics, sands and soils, porous energetic materials (explosives, reactive mixtures), and foams exhibit interesting behaviors due to their heterogeneity and critical length scale, typically commensurate with the grain or pore size. Under extreme conditions of impact, granular and porous materials display highly localized phenomena such as fracture, inelastic deformation, and the closure of voids, which in turn strongly influence the bulk response. Due to the complex nature of these interactions and the short time scales involved, computational methods have proven to be powerful tools to investigate these phenomena. Thus, the coupled use of experiment, theory, and simulation is critical to advancing our understanding of shock processes in initially porous and granular materials. This is a comprehensive volume on granular and porous materials for researchers working in the area of shock and impact physics. The book is divided into three sections, where the first presents the fundamentals of shock physics as it pertains to the equation of state, compaction, and strength properties of porous materials. Building on these fundamentals, the next section examines several applications where dynamic processes involving initially porous materials are prevalent, focusing on the areas of penetration, planetary impact, and reactive munitions. The final section provides a look at emerging areas in the field, where the expansion of experimental and computational capabilities are opening the door for new opportunities in the areas of advanced light sources, molecular dynamics modeling, and additively manufactured porous structures. By intermixing experiment, theory, and simulation throughout, this book serves as an excellent, up-to-date desk reference for those in the field of shock compression science of porous and granular materials.

Mathematics and Mechanics of Granular Materials

Mathematics and Mechanics of Granular Materials

Granular or particulate materials arise in almost every aspect of our lives, including many familiar materials such as tea, coffee, sugar, sand, cement and powders. At some stage almost every industrial process involves a particulate material, and it is usually the cause of the disruption to the smooth running of the process. In the natural environment, understanding the behaviour of particulate materials is vital in many geophysical processes such as earthquakes, landslides and avalanches. This book is a collection of current research from some of the major contributors in the topic of modelling the behaviour of granular materials. Papers from every area of current activity are included, such as theoretical, numerical, engineering and computational approaches. This book illustrates the numerous diverse approaches to one of the outstanding problems of modern continuum mechanics.

Trends in Continuum Mechanics of Porous Media

Trends in Continuum Mechanics of Porous Media

Over the last decade and particularly in recent years, the macroscopic porous media theory has made decisive progress concerning the fundamentals of the theory and the development of mathematical models in various fields of engineering and biomechanics. This progress has attracted some attention, and therefore conferences devoted almost exclusively to the macrosopic porous media theory have been organized in order to collect all findings, to present new results, and to discuss new trends. Many important contributions have also been published in national and international journals, which have brought the porous media theory, in some parts, to a close. Therefore, the time seems to be ripe to review the state of the art and to show new trends in the continuum mechanical treatment of saturated and unsaturated capillary and non-capillary porous solids. This book addresses postgraduate students and scientists working in engineering, physics, and mathematics. It provides an outline of modern theory of porous media and shows some trends in theory and in applications.

IUTAM Symposium on Theoretical and Numerical Methods in Continuum Mechanics of Porous Materials

Proceedings of the IUTAM Symposium held at the University of Stuttgart, Germany, September 5–10, 1999

IUTAM Symposium on Theoretical and Numerical Methods in Continuum Mechanics of Porous Materials

During the last decades, continuum mechanics of porous materials has achieved great attention, since it allows for the consideration of the volumetrically coupled behaviour of the solid matrix deformation and the pore-fluid flow. Naturally, applications of porous media models range from civil and environmental engineering, where, e. g. , geote- nical problems like the consolidation problem are of great interest, via mechanical engineering, where, e. g. , the description of sinter materials or polymeric and metallic foams is a typical problem, to chemical and biomechanical engineering, where, e. g. , the complex structure of l- ing tissues is studied. Although these applications are principally very different, they basically fall into the category of multiphase materials, which can be described, on the macroscale, within the framework of the well-founded Theory of Porous Media (TPM). With the increasing power of computer hardware together with the rapidly decreasing computational costs, numerical solutions of complex coupled problems became possible and have been seriously investigated. However, since the quality of the numerical solutions strongly depends on the quality of the underlying physical model together with the experimental and mathematical possibilities to successfully determine realistic material parameters, a successful treatment of porous materials requires a joint consideration of continuum mechanics, experimental mechanics and numerical methods. In addition, micromechanical - vestigations and homogenization techniques are very helpful to increase the phenomenological understanding of such media.

Mechanics of Granular Media

Mechanics of Granular Media

This monograph covers phenomena of deformation and machining of granular media: macroscopic particles of different size, shape, and surface properties which typically exhibit behavior similar to fluids, as well as the behavior of solids under deformation. The book analyses the behavior of granular media in soils, rocks and stones, metals and various synthetic materials, presenting a theoretical description, applications and understanding of basic phenomena in granular matter.

Soil Mechanics and Transport in Porous Media

Selected Works of G. de Josselin de Jong

Soil Mechanics and Transport in Porous Media

"This book contains an overview of the most relevant scientific contributions of Gerard de Josselin de Jong to the development of both Soil Mechanics and Transport in Porous Media. The volume comprises a selection of papers by de Josselin de Jong as they were published in the international scientific literature. In addition, some unpublished, but highly relevant work has been included. The selected papers were published in the period 1950-1990. They clearly demonstrate the development of ideas and the profound contributions of de Josselin de Jong." "This volume is intended for scientists, and engineers, working in geohydrology, geotechnical engineering, soil mechanics, environmental engineering, and transport in porous media. In addition, the volume will be of interest to students studying one of the aforementioned fields."--Jacket.

Kinetic and Continuum Theories of Granular and Porous Media

Kinetic and Continuum Theories of Granular and Porous Media

This book is an account on the thermomechanical behaviour of granular and porous materials and deals with experiments, theoretical deduction of macroscale equations by means of averaging from microscale properties, embedding the macroscopic description into a continuum-thermodynamical and statistical context and analysis of solutions of macroscopic models by numerical techniques. It addresses itself to engineers (chemical, civil, mechanical) applied mathematicians and physicists at the advanced student or Ph. D. level at universities, research centres and in industry.