ECSS-E-HB-32-20 (PART-6A), SPACE ENGINEERING: STRUCTURAL MATERIALS HANDBOOK - PART 6: FRACTURE AND MATERIAL MODELING, CASE STUDIES AND DESIGN AND INTEGRITY CONTROL AND INSPECTION (20-MAR-2011)

ECSS-E-HB-32-20 (PART-6A), SPACE ENGINEERING: STRUCTURAL MATERIALS HANDBOOK - PART 6: FRACTURE AND MATERIAL MODELING, CASE STUDIES AND DESIGN AND INTEGRITY CONTROL AND INSPECTION (20-MAR-2011)., The Structural materials handbook, ECSS-E-HB-32-20, is published in 8 Parts. A glossary of terms, definitions and abbreviated terms for these handbooks is contained in Part 8. The fracture behaviour of metallic and ceramic matrix composites is more complex than that of unreinforced alloys or monolithic ceramics. The fracture characteristics of the more isotropic variants are now well understood and predictive models are widely accepted, e.g. Linear Elastic Fracture Mechanics (LEFM), [See also: ECSS‐E‐32‐01 – Fracture control]. For newer composite materials, attempts have been made to describe and predict their behaviour by extending the models for their more isotropic counterparts. Success has been limited by the anisotropy of the composites, especially for those with continuous fibres. In reality, anisotropic metallic and ceramic composites need to be considered as new classes of materials. Some CMC materials, destined for use in TPS on reusable vehicles, have been investigated for appropriate selection and use of failure criteria, [See: 64.5]. Metal matrix composites are particularly difficult as they show elastic‐plastic deformation characteristics, where the degree of plastic deformation is influenced by many factors. Ceramic composites are elastic in behaviour, although accumulated matrix microcracking gives nonlinear deformation characteristics. These composites are desirable because of their high temperature operating capabilities. This chapter covers three discrete groups of composites: • Particulate reinforced metals (MMCp). • Fibre reinforced metals (MMCf). • Inorganic ceramic matrix composites (ICMCf). Whisker reinforced metals or ceramics are not explicitly covered because they are primarily of non‐ European origin and in some European countries whiskers are thought to present health hazards. The different fracture behaviours of each are described. In particular, the interrelation between residual stresses and thermo‐mechanical fatigue effects is highlighted. As materials are pushed towards their physical and chemical limits, the shorter the period that they can sustain the combined effects of thermal cycling, mechanical and thermal stresses and oxidation.