Mechanics of Creep Brittle Materials 1

ISBN-13: 9789401069946 / Angielski / Miękka / 2011 / 310 str.

A. C. F. Cocks; A. R. S. Pontern

Opis

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.

Spis treści

1. Crack Propagation in Creeping Bodies.- The brittle-to-ductile transition in silicon.- Stress redistribution effects on creep crack growth.- Contour integrals for creep crack growth analysis.- Modelling of creep crack growth.- Modelling creep-crack growth processes in ceramic materials.- On the growth of cracks by creep in the presence of residual stresses.- 2. Deformation and Failure of Engineering Ceramics.- Creep deformation of engineering ceramics.- Statistical mapping and analysis of engineering ceramics data.- Indentation creep in zirconia ceramics between 290 K and 1073 K.- Ductile creep cracking in uranium dioxide.- Physical interpretation of creep and strain recovery of a glass ceramic near glass transition temperature.- 3. Ice Mechanisms and Mechanics.- Ice loading on offshore structures: the influence of ice strength.- Ice forces on wide structures: field measurements at Tarsuit Island.- The double torsion test applied to fine grained freshwater columnar ice, and sea ice.- Ice and steel: a comparison of creep and failure.- A micromechanics based model for the creep of ice including the effects of general microcracking.- 4. The Growth of Continuum Damage in Creeping Materials.- Continuum damage mechanics applied to multi-axial cyclic material behaviour.- Multiaxial stress rupture criteria for ferritic steels.- Segregation of impurities in a heat-affected and an intercritical zone in an operated 0.5Cr 0.5Mo 0.25V steel.- Effect of creep cavitation at sliding grain boundaries.- Creep fracture under remote shear.