Tabela A z publikacjami w czasopismach wyróżnionych w Journal Citation Reports (JCR) 
Tabela B z publikacjami w czasopismach zagranicznych i krajowych, wyróżnionych na liście MNSzW
Publikacje konferencyjne indeksowane w bazie Web of Science Core Collection
Inne publikacje w pozostałych czasopismach i wydawnictwach konferencyjnych
Afiliacja IPPT PAN

1.Postek E., Sadowski T., Impact model of WC/Co composite, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2019.01.084, No.213, pp.231-242, 2019
Postek E., Sadowski T., Impact model of WC/Co composite, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2019.01.084, No.213, pp.231-242, 2019

Abstract:
WC/Co composite is a standard hard material used for the production of cutting tools. It has both very good thermo-mechanical and wear properties. During the cutting, process tools are subjected to impact loading and gradual degradation due to high-stress concentrations. This loading induced deterioration is complex process still not well investigated and explained.Up till now the dynamic response of the WC/Co composite was analysed under dynamic impulse compressive loading [1]. However, the behaviour of the above two-phase composite under impacts conditions was not investigated in details. In the presented micromechanical approach the real material structure geometry of the internal structure can be performed including spatial distribution of: (1) WC grains and their dimensions, (2) volume content of plastic Co binder with their thickness, (3) system of grain/binder interfaces and (4) cracks initiated and developed during impulse loading, (5) possible brittle grains rotation.The results reveal the dependence of the microcracking processes and the stress distribution on impact velocity and presence of discontinuities in the Co binder and the interface zone between the binders and the grains. The microcracks system was evaluated by the damage parameter according to Kachanov, 1986 [62].

Keywords:
Cermet; Impact load; Microcracking; Cohesive elements; Numerical modelling;

(40p.)
2.Madan N., Rojek J., Nosewicz S., Convergence and stability analysis of the deformable discrete element method, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.6014, pp.1-22, 2019
Madan N., Rojek J., Nosewicz S., Convergence and stability analysis of the deformable discrete element method, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.6014, pp.1-22, 2019

Abstract:
This work investigates numerical properties of the algorithm of the discrete element method employing deformable circular discs presented in an earlier authors' publication. The new formulation, called the deformable discrete element method (DDEM) enhances the standard discrete element method (DEM) by introducing an additional (global) deformation mode caused by the stresses in the particles induced by the contact forces. An accurate computation of the contact forces would require an iterative solution of the implicit relationship between the contact forces and particle displacements. In order to preserve efficiency of the DEM, the new formulation has been adapted to the explicit time integration. It has been shown that the explicit DDEM algorithm is conditionally stable and there are two restrictions on its stability. Except for the limitation of the time step as in the standard DEM, the stability in the DDEM is governed by the convergence criterion of the iterative solution of the contact forces. The convergence and stability limits have been determined analytically and numerically for selected regular and irregular configurations. It has also been found out that the critical time step in DDEM remains unchanged with respect to standard DEM.

Keywords:
discrete element method; deformable particles; iterative solution; convergence criterion;explicit scheme; stability

(40p.)
3.Chmielewski M., Nosewicz S., Wyszkowska E., Kurpaska Ł., Strojny-Nędza A., Piątkowska A., Bazarnik P., Pietrzak K., Analysis of the micromechanical properties of copper-silicon carbide composites using nanoindentation measurements, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.01.257, Vol.45, No.7A, pp.9164-9173, 2019
Chmielewski M., Nosewicz S., Wyszkowska E., Kurpaska Ł., Strojny-Nędza A., Piątkowska A., Bazarnik P., Pietrzak K., Analysis of the micromechanical properties of copper-silicon carbide composites using nanoindentation measurements, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.01.257, Vol.45, No.7A, pp.9164-9173, 2019

Abstract:
The study presents a detailed analysis of the impact of the coating type of silicon carbide particles and its share by volume on the microstructure and micromechanical properties of Cu-SiC composites. In order to protect the carbide from decomposition during the manufacturing of the composites, the surface of SiC was modified via a plasma vapour deposition technique with a layer of metals (W, Cr, Ti and Ni). Composites with a variable share of the ceramic phase (10–50 %vol.) were obtained at a temperature of 950 °C using spark plasma sintering. An analysis of the structures of the composites, especially in the metal-ceramic boundary region, was conducted with the use of scanning and transmission electron microscopy. The mechanical properties of the composites in the Cu-interface-SiC system were studied via a nanoindentation technique. The comparison of the results of hardness and Young's modulus studies were completed in relation to the actual structures of the materials, which in turn made it possible to determine the impact of the interfacial structure on the global properties of the composite materials.

Keywords:
Copper-silicon carbide composites; Nanoindentation; SPS; Interface study

(40p.)
4.Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete Element Modeling of Intermetallic Matrix Composite Manufacturing by Powder Metallurgy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020281, Vol.12, No.281, pp.1-18, 2019
Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete Element Modeling of Intermetallic Matrix Composite Manufacturing by Powder Metallurgy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020281, Vol.12, No.281, pp.1-18, 2019

Abstract:
This paper presents a numerical and experimental analysis of manufacturing of intermetallic ceramic composites by powder metallurgy techniques. The scope of the paper includes the formulation and development of an original numerical model of powder metallurgy of two-phase material within the framework of the discrete element method, simulations of powder metallurgy processes for different combinations of process parameters, and a verification of the numerical model based on own experimental results. Intermetallic-based composite NiAl–Al2O3 has been selected as representative material for experimental and numerical studies in this investigation. Special emphasis was given to the interactions between the intermetallic and ceramic particles by formulating the special model for adhesive contact bond. In order to properly represent a real microstructure of a two-phase sintered body, a discrete element specimen was generated using a special algorithm. Numerical validation showed the correct numerical representation of a sintered two-phase composite specimen. Finally, micromechanical analysis was performed to explain the macroscopic behavior of the sintered sample. The evolution of the coordination number, a number of equilibrium contacts, and the distribution of the cohesive neck size with respect to time are presented.

Keywords:
powder metallurgy; sintering; discrete element method; modeling; intermetallic matrix composites

(35p.)
5.Meissner M., Wiśniewski K., Influence of room modes on low-frequency transients: Theoretical modeling and numerical predictions, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1016/j.jsv.2019.02.012, Vol.448, pp.19-33, 2019
Meissner M., Wiśniewski K., Influence of room modes on low-frequency transients: Theoretical modeling and numerical predictions, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1016/j.jsv.2019.02.012, Vol.448, pp.19-33, 2019

Abstract:
In the low-frequency range, a sound reproduction in enclosures is strongly influenced by excited room modes. While the spectral impact of acoustic modes on a room response is well recognized, there is no sufficient knowledge on how these modes affects transients. In the paper this issue has been examined theoretically and numerically for a room excited by a tone burst by using a modal expansion method supported by a computer implementation. To quantify a temporal accuracy of a sound reproduction, the new metrics referred to as the tone burst reproduction error was introduced. The basis for determining this quantity was a deviation between the tone burst amplitude and the amplitude of a sound pressure computed via the Hilbert transform. A numerical simulation was performed for an irregularly shaped enclosure having a form of two-room coupled system. Calculation results have proved that a high inaccuracy of a tone burst reproduction occurs at receiving points corresponding to sharp dips in a distribution of the steady-state sound pressure level. This is because in these points an amplitude of transient sound is much bigger than a tone burst amplitude. It was discovered that strong narrow peaks in the tone burst reproduction error are located at centers of vortices in the active sound intensity vector field. An influence of a sound damping in a room on a reproduction of a tone burst was also examined and it was found that a substantial increase in a wall sound absorption does not significantly improves a tone burst reproduction because it does not eliminate sharp dips in a distribution of the steady-state sound pressure level.

Keywords:
room acoustics, room modes, transients, tone burst, discrete Hilbert transform, sound intensity vector field

(35p.)
6.Nosewicz S., Rojek J., Wawrzyk K., Kowalczyk P., Maciejewski G., Maździarz M., Multiscale modeling of pressure-assisted sintering, COMPUTATIONAL MATERIALS SCIENCE, ISSN: 0927-0256, DOI: 10.1016/j.commatsci.2018.10.001, Vol.156, pp.385-395, 2019
Nosewicz S., Rojek J., Wawrzyk K., Kowalczyk P., Maciejewski G., Maździarz M., Multiscale modeling of pressure-assisted sintering, COMPUTATIONAL MATERIALS SCIENCE, ISSN: 0927-0256, DOI: 10.1016/j.commatsci.2018.10.001, Vol.156, pp.385-395, 2019

Abstract:
This report presents the modeling of pressure-assisted sintering within the framework of a multiscale approach. Three individual numerical methods have been collectively applied to predict the behavior of a sintering body at three different scales. The appropriate solutions to connect each model/scale have been proposed. Molecular dynamics have been employed to evaluate the grain boundary diffusion coefficient at the atomistic scale. The obtained results of diffusive parameters have been transferred to the micromechanical model of sintering. Here, the discrete element method was used to represent the sintered material properties at the microscopic scale. Micromechanical based results have been validated by own experimental data of material density evolution, indicating the required coincidence. The transfer from micro- to the macroscopic model has been realized by determining the macroscopic viscous moduli from discrete element simulations and subsequently applying them to the continuum model of sintering. The numerical results from finite element simulations at the macroscopic scale have been compared with discrete element ones.

Keywords:
Sintering; Multiscale modeling; Discrete element method; Molecular dynamics; Finite element method

(30p.)
7.Romelczyk-Baishya B., Lumelskyj D., Stępniewska M., Giżyński M., Pakieła Z., The mechanical properties at room and low temperature of p110 steel characterised by means of small punch test, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126232, Vol.64, No.1, pp.159-165, 2019
Romelczyk-Baishya B., Lumelskyj D., Stępniewska M., Giżyński M., Pakieła Z., The mechanical properties at room and low temperature of p110 steel characterised by means of small punch test, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126232, Vol.64, No.1, pp.159-165, 2019

Abstract:
In this paper, small punch test (SPT) which is one of miniaturized samples technique, was employed to characterize the mechanical properties of carbon steel P110. The tests were carried out in the range of –175°C to RT. Results obtained for SPT were compared to those calculated for tensile and Charpy impact test. Based on tensile and SPT parameters numerical model was prepared. 8 mm in diameter and 0.8 mm in height (t) discs with and without notch were employed in this research. The specimens had different depth notch (a) in the range of 0.1 to 0.4 mm. It was estimated that α factor for comparison of Tsp and DBTT for carbon steel P110 is 0.55 and the linear relation is DBTT = 0.55TSPT. The numerical model fit with force – deflection curve of SPT. If the factor of notch depth and samples thickness is higher than 0.3 the fracture mode is transformed from ductile to brittle at –150°C.

Keywords:
small punch test, carbon steel P110, small samples, low temperature, mechanical properties

(30p.)