Modelling of damage and fracture processes of ceramic matrix composites under mechanical loading
The present contribution focuses on the problem of mechanical response of the composite ceramic material containing internal structure. This initial internal structure of the material consists of: grains, intergranular layers, initial defects (like porosi
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Department of Solid Mechanics, Lublin University of Technology, Lublin, Poland
Abstract The present contribution focuses on the problem of mechanical response of the composite ceramic material containing internal structure. This initial internal structure of the material consists of: grains, intergranular layers, initial defects (like porosity or microcracks) and initial reinforcement. During deformation process the initial structure of the material changes (evolves) due to development of dislocation bands, local stress concentration and further nucleation of microdefects, their growth into mesocracks and finally to macrocracks leading to the failure of the material. This contribution describes all phases of deformation process of polycrystalline of composite ceramic material including phenomena governing changes of internal structure of the material like: nucleation, growth of defects. In particular to the description of the material response including internal damage process, the micromechanical approach will be used by application of averaging procedures. In order to show local stress concentrations the Finite Element Analysis (FEA) will be applied.
1. Introduction – variety of different composite materials Nowadays modern structural parts of different engineering structures including: cars, aircrafts, buildings etc. requires application of new composite materials with different internal structure introduced by technological process. This internal structure is specially introduced to the materials, to modify their properties in order to get: excellent mechanical properties, lightweight, low cost and high security of structural elements, very safe constructions for potential users. It is particularly important in case of critical parts designing of the advanced technology structures like rocket or aircrafts for military or civil applications, nuclear power and wing power plants etc. Examples of these modern applications are: elements for thermal barrier protection of spacecrafts (ceramic matrix composites - CMC, including nanoparticles), elements of engines (e.g. turbine blades protected by thermal barrier coating (TBC)), thermal shielding of elements in nuclear reactors, structural elements of aircrafts, e.g. wings or fuselage (made with difT. Sadowski, P. Trovalusci (Eds.), Multiscale Modeling of Complex Materials: Phenomenological, Theoretical and Computational Aspects, CISM International Centre for Mechanical Sciences DOI 10.1007/ 978-3-7091-1812-2_5 © CISM Udine 2014
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T. Sadowsky
ferent types of sandwich composites based on fibre-metal laminates (ARAL or GLARE), e.g. Boening 767). Other modern applications are different types of composite structures made of various types of materials including nano-particles, foams (layered, functionally graded or with specially oriented or stochastically distributed reinforcements), hybrid joints of critical structural elements with mixing various materials and various joining techniques (bonding, riveting, clinching, spot and shear friction welding, laser beam wel
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