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Modelling of the randomly formed ceramic foam structure for FEM simulations
Papšík, Roman ; Navrátil, Petr (referee) ; Ševeček, Oldřich (advisor)
This bachelor thesis deals with construction of ceramic foam model with various levels of (ir)regularity for finite element simulations in Ansys. The main objective is to substitute the complex structure of the open cell foam using the beam elements, enabling to perform FE analysis on much larger volumes of foams than the realistic foam models composed of solid elements. In this work, the technique of the model creation is based on the Voronoi tessellation and enables choice of arbitrary (ir)regularity of the modelled structure. The created source codes generate the model data directly in the syntax of APDL language for FEM system Ansys. The first part of the work describes several methods of the space partitioning and methods for substitution of the real foam structure by simplified “wire” model. The second part defines the Voronoi tessellation (diagram) as a key technique for creation of the foam model and describes its algorithms. The next part of the work deals with possibilities and utilizations of various software and libraries, describes creation of the own code in mathematical software Matlab and way how to transfer the model data into the system Ansys. The last part of the work demonstrates functionality of the created model on several FEM simulations, studying response of the ceramic foam on the external mechanical loading, upon consideration of various levels of the foam structure irregularity.
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Tensile strength of alumina based ceramics foam
Řehořek, Lukáš ; Chlup, Zdeněk
In last years cellular materials are getting to focus of an interest in a number of industrial applications and science fields. These materials are often used for filtration of different mediums such as melts or in aerospace industry and even in tissue engineering. Hence, there is evolved effort to understand and describe mechanical and physical properties of these interesting materials. While behaviour of these materials in compression is well understand and published, tensile tests are not so frequent and concerning ceramic cellular materials they are highly rare. The methodology of evaluation of tensile properties of model ceramic foam material VUKAPOR((R))A used like filters in metallurgy was developed. This methodology is based on fixation of ceramic foam sample by specialised resin to a holder. Homogenous transfer of forces is ensured by this technique.
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Tensile testing of high porous ceramic materials
Řehořek, Lukáš ; Chlup, Zdeněk ; Dlouhý, Ivo
In last years cellular materials are getting to focus of an interest in a number of industrial applications and science fields. These materials are often used for filtration of different mediums or in aerospace industry and even in tissue engineering. Hence, there is effort to understand and describe mechanical and physical properties of these materials. While behaviour of these materials in compression is well understand and published, tensile tests are not so frequent and concerning ceramic cellular materials they are highly rare. The methodology of evaluation of tensile properties of model ceramic open-pore foam material VUKAPOR((R))A used like filters in metallurgy was developed. This methodology is based on fixation of ceramic foam sample by specialised resin to a holder. Homogenous transfer of forces is ensured by this technique. Specimens of two sizes – 10x10x30mm and 15x15x40mm were tested. Ceramic foams with two pore densities – 10 PPI and 60 PPI have been investigated.
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