A.C.F. Cocks – författare

This volume contains 39 contributions presented at the IUTAM Symposium on Mechanics of Granular and Porous Materials. The Symposium reviewed the current understanding of the constitutive behaviour of porous and granular solids, based on experimental data, numerical simulations and micromechanical models. An interdisciplinary approach is adopted, involving the fields of solid mechanics, materials science, geomechanics, chemical engineering and mathematics. This book emphasizes the development and use of constitutive laws to model practical processes such as mixing, drainage and drying, compaction of metal and ceramic powders and soils, and instabilities associated with these processes. A common theme is the development of constitutive models from an understanding of the underlying physical mechanisms of deformation and fracture. The volume should be of interest to researchers and to engineers concerned with measuring and predicting the response of granular and porous solids for structural applications.

Mechanics of Creep Brittle Materials-l was published in 1989 as the proceedings of a Colloquium held in Leicester in the summer of 1988. The Colloquium examined the creep response of a wide range of materials, including metals, engineering ceramics and ice, with the aim of determining similarities in the response of these materials and the way in which their behaviour is modelled. The proceedings were structured so as nature of the Colloquium, with papers to reflect the interdisciplinary grouped together largely on the basis of the phenomena being examined, rather than by class of material. Mechanics of Creep Brittle Materials-2 was held in Leicester in Septem­ ber 1991 to discuss advances made in our understanding of the response of creep brittle materials since the first Colloquium. The scope of the Colloquium was extended to include mineral salts, concrete and com­ posite systems. These proceedings are once more structured so that the reader can readily compare the response of different material systems and evaluate the suitability of the range of models presented to the materials he is interested in. In fact a number of papers directly compare the of a range of different materials with the aim of identifying behaviour general strategies for the testing and modelling of creeping materials.

Failure of components which operate in the creep range can result either from the growth of a dominant crack or through the accumulation of ''damage'' in the material. Conventional and nuclear power generating plant are generally designed on the basis of continuum failure, with assessment routes providing an indication of the effects of flaws on component performance. Another example where an understanding of creep failure is important is in the design of offshore structures which operate in arctic waters. These structures can be subjected to quite considerable forces by wind-driven ice sheets, which are limited by failure of the ice sheet. Design codes are currently being developed which identify the different mechanisms of failure, ranging from continuum crushing to radial cracking and buckling of the ice sheet. Our final example concerns engineering ceramics, which are currently being considered for use in a wide range of high-temperature applications. A major problem preventing an early adoption of these materials is their brittle response at high stresses, although they can behave in a ductile manner at lower stresses. In each of the above situations an understanding of the processes of fast fracture, creep crack growth and continuum failure is required, and in particular an understanding of the material and structural features that influence the transition from brittle to ductile behaviour. The translation of this information to component design is most advanced for metallic components.

This volume constitutes the Proceedings of the IUT AM Symposium on Mechanics of Granular and Porous Materials, held in Cambridge from 15th to 17th July 1996. The objectives were: 1. To review existing experimental results and practical phenomena on the flow and compaction of particulate media; 2. To review the current state of constitutive models, and their implementation for predicting the macroscopic response. 3. Identification of the shortcomings of existing models and procedures in understanding practical phenomena. The Symposium brought together the research communities of solid mechanics, materials science, geomechanics, chemical engineering and mathematics to review current knowledge of the flow and compaction of granular and porous media. The meeting emphasised the development and use of constitutive laws to model practical processes such as mixing, drainage and drying, compaction of metal and ceramic powders and soils, and instabilities associated with these processes. A common theme was to develop constitutive models from an understanding of the underlying physical mechanisms of deformation and fracture. It was particularly rewarding to find that the separate research communities came together during the meeting and came to a consensus as to the main mechanisms of deformation and failure of particulate and porous solids.

Failure of components which operate in the creep range can result either from the growth of a dominant crack or through the accumulation of 'damage' in the material. Conventional and nuclear power generating plant are generally designed on the basis of continuum failure, with assessment routes providing an indication of the effects of flaws on component performance. Another example where an understanding of creep failure is important is in the design of offshore structures which operate in arctic waters. These structures can be subjected to quite considerable forces by wind-driven ice sheets, which are limited by failure of the ice sheet. Design codes are currently being developed which identify the different mechanisms of failure, ranging from continuum crushing to radial cracking and buckling of the ice sheet. Our final example concerns engineering ceramics, which are currently being considered for use in a wide range of high-temperature applications. A major problem preventing an early adoption of these materials is their brittle response at high stresses, although they can behave in a ductile manner at lower stresses. In each of the above situations an understanding of the processes of fast fracture, creep crack growth and continuum failure is required, and in particular an understanding of the material and structural features that influence the transition from brittle to ductile behaviour. The translation of this information to component design is most advanced for metallic components.

Mechanics of Creep Brittle Materials-l was published in 1989 as the proceedings of a Colloquium held in Leicester in the summer of 1988. The Colloquium examined the creep response of a wide range of materials, including metals, engineering ceramics and ice, with the aim of determining similarities in the response of these materials and the way in which their behaviour is modelled. The proceedings were structured so as nature of the Colloquium, with papers to reflect the interdisciplinary grouped together largely on the basis of the phenomena being examined, rather than by class of material. Mechanics of Creep Brittle Materials-2 was held in Leicester in Septem­ ber 1991 to discuss advances made in our understanding of the response of creep brittle materials since the first Colloquium. The scope of the Colloquium was extended to include mineral salts, concrete and com­ posite systems. These proceedings are once more structured so that the reader can readily compare the response of different material systems and evaluate the suitability of the range of models presented to the materials he is interested in. In fact a number of papers directly compare the of a range of different materials with the aim of identifying behaviour general strategies for the testing and modelling of creeping materials.