Identification of nanosized defects using tribospectroscopy. Modeling by movable cellular automaton method

The work describes the application of the movable cellular automaton method for the simulation of typical situations of nano-scale crack identification in ceramic coatings by the spectral analysis of friction force continuously registered using a small counter-body moving over the coating surface. It is shown that the Fourier spectra of the friction force have peaks that correspond to the distance between the nanocracks oriented perpendicular and at some angle to the tested surface. The obtained results allow to conclude that the appearance of cracks on the Fourier spectra of friction force depends on their orientation. Thus, the distance between cracks, their orientation and sizes can be identified by the method of tribospectroscopy

Identification of nanosized defects using tribospectroscopy. Modeling by movable cellular automaton method

The work describes the application of the movable cellular automaton method for the simulation of typical situations of nano-scale crack identification in ceramic coatings by the spectral analysis of friction force continuously registered using a small counter-body moving over the coating surface. It is shown that the Fourier spectra of the friction force have peaks that correspond to the distance between the nanocracks oriented perpendicular and at some angle to the tested surface. The obtained results allow to conclude that the appearance of cracks on the Fourier spectra of friction force depends on their orientation. Thus, the distance between cracks, their orientation and sizes can be identified by the method of tribospectroscopy

Numerical study of mechanical behavior of ceramic composites under compression loading in the framework of movable cellular automaton method

Movable cellular automaton method was used for investigating the mechanical behavior of ceramic composites under uniaxial compression. A 2D numerical model of ceramic composites based on oxides of zirconium and aluminum with different structural parameters was developed using the SEM images of micro-sections of a real composite. The influence of such structural parameters as the geometrical dimensions of layers, inclusions, and their spatial distribution in the sample, the volume content of the composite components and their mechanical properties (as well as the amount of zirconium dioxide that underwent the phase transformation) on the fracture, strength, deformation and dissipative properties was investigated

On the dependence of effective mechanical properties of ceramics on partial concentrations of different size pores in its structure

In the framework of the movable cellular automata method we have developed a plane/2D model of mechanical behavior of brittle porous material under shear loading. The work considers the material characterized by a function of pore size distribution with two maxima. Based on simulation results, the authors proposed the analytical estimation of the dependence of strength and elastic properties of the material on its total porosity and partial porosities that correspond to the pores with different sizes

On the dependence of effective mechanical properties of ceramics on partial concentrations of different size pores in its structure

In the framework of the movable cellular automata method we have developed a plane/2D model of mechanical behavior of brittle porous material under shear loading. The work considers the material characterized by a function of pore size distribution with two maxima. Based on simulation results, the authors proposed the analytical estimation of the dependence of strength and elastic properties of the material on its total porosity and partial porosities that correspond to the pores with different sizes

3D modeling of the mechanical behavior of ceramics with pores of different size

Movable cellular automaton method was used for simulating uniaxial compression of 3D porous ceramic samples. Pores were considered explicitly by removing randomly selected automata from the original FCC packing. Distribution of pores in space, their size and the total fraction were varied. It is shown that the relation between mechanical properties of the material and its porosity significantly depends on the pore size. Thus, value of the elastic modulus of the samples with large pores is greater than that of the samples with small pores by average value of 3%-16%. Strength value of the samples with large pores is less than that of the samples with small pores by average value of 12% up to the porosity of 0.55, and then becomes to be greater. When the samples contain small and large pores there is a maximum of mechanical properties at ratio of volumes of large and small pores of about 0.75

The numerical study of fracture and strength characteristics of heterogeneous brittle materials under dynamic loading

In the present paper the multiscale approach to the construction of rheological models of brittle materials with heterogeneous internal structure is implemented within the numerical method of movable cellular automata. An example of application of the implemented approach to determine the mechanical properties (including parameters of the rheological model and strength) of brittle materials with complicated internal structure at both macroscopic and mesoscopic scales is described. The effect of strain rate on brittle materials behavior under uniaxial compression and tension is analyzed

The numerical study of fracture and strength characteristics of heterogeneous brittle materials under dynamic loading

In the present paper the multiscale approach to the construction of rheological models of brittle materials with heterogeneous internal structure is implemented within the numerical method of movable cellular automata. An example of application of the implemented approach to determine the mechanical properties (including parameters of the rheological model and strength) of brittle materials with complicated internal structure at both macroscopic and mesoscopic scales is described. The effect of strain rate on brittle materials behavior under uniaxial compression and tension is analyzed