1. |
Postek E., Sadowski T.♦, Tahani M., Guhathakurta J.♦, Numerical Model of Metal-Ceramic Composite with Interphase Properties,
WCCM2024 and PANACAM2024, 16th World Congress on Computational Mechanics and 4th Pan American Congress on Computational Mechanics, 2024-07-21/07-26, Vancouver, British Columbia (CA), pp.1, 2024Streszczenie: Multiphase metal matrix composites are used in modern industries like energy, aerospace, and automotive. The materials are used in severe loading conditions like impact loads or thermal shocks. The presentation concerns a data-driven model of an interpenetrated composite. The geometry of the material phases is obtained using CT scanning. Further details, namely, the distribution of voids and inclusions are found with the scanning as well. Based on CT scans the 3D finite element and peridynamics models are derived from. Former analyses [1, 2] showed the importance of the existence of an interface zone in multiphase composites. In the current presentation, the diffusion-based mechanism of forming the interphase zone is shown. A constitutive law evaluated in [3] is considered. The constitutive law for the cohesive zone was obtained using molecular dynamics simulations. The effects of the MD-based law on mesoscale samples are presented. Acknowledgment: Grant from National Science Committee (PL) UMO-2019/33/B/ST8/01263; Polish National Agency for Academic Exchange (NAWA) [BPN/ULM/2021/1/00115/U/DRAFT/00001] Calculations: PL-GRID National Facilities: CYFRONET, Krakow, ICM at the University of Warsaw, TASK, Gdansk, Poland, and LUMI in Kajaani, Finland. References: [1] Felten, F., Schneider, G., and Sadowski T. Estimation of R-curve in WC/Co cermet by CT test. Int. J. Refract. Hard. Met., Vol. 26, pp. 55-60, 2008. [2] Postek, E. and Sadowski, T. Qualitative comparison of dynamic compressive pressure load and impact of WC/Co composite. Int. J. Refract. Hard. Met., Vol. 77, pp. 68-81, 2018. [3] Tahani, M., Postek, E., and Sadowski T., Investigating the Influence of Diffusion on the Cohesive ZoneModel of the SiC/Al Composite Interface, Molecules, Vol.28, No.19, pp. 6757-1-6757-19, 2023. Słowa kluczowe: Multiphase materials, Diffusion, Consitituve law, Molecular dynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) | Tahani M. | - | IPPT PAN | Guhathakurta J. | - | CT-LAB Stuttgart (DE) |
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2. |
Fathalian M., Postek E., Tahani M., Sadowski T.♦, Investigating the Mechanical Characteristics of Al2O3 through Density Functional Theory and Molecular Dynamics,
KUKDM 2024, Konferencja Użytkowniów Komputerów Dużej Mocy, 2024-03-13/03-15, Zakopane (PL), pp.17-18, 2024Streszczenie: This exploration highlights the essential role of ceramics, nota bly aluminum oxide (Al2O3 ),
in various technological applications due to its remarkable properties, including high mecha-
nical strength and electrical insulation. It underscores the transformative impact of com-
putational approaches such as density functional theory (DFT) and molecular dynamics (MD)
simulations in unraveling Al2O3’s mechanical characteristics. The focus is on key attributes like
surface energy, Young’s modulus, and fracture toughness, providing insights into the atomic-scale mechanisms governing these features. Through the application of DFT and MD simulations, a deeper understanding emerges regarding how cracks initiate, propagate, and influence overall
fracture behavior, contributing to the advancement of enhanced materials for diverse applica-
tions. Słowa kluczowe: alumina, mechanical properties, crack development, density functional theory, molecular dynamics, Afiliacje autorów:
Fathalian M. | - | IPPT PAN | Postek E. | - | IPPT PAN | Tahani M. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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3. |
Fathalian M., Postek E., Sadowski T.♦, Crack Development In Al2O3: A DFT Study,
KSME, Korean Society of Mechanical Engineers Annual Meeting, 2023-11-01/11-04, Incheon (KR), pp.1-1, 2023Streszczenie: This study employs Density Functional Theory (DFT) simulations to explore the fracture toughness
(KIC), surface energy (γ), and Young's modulus (E) of α-Al2O3 (aluminum oxide) while investigating the impact of vacancies on these mechanical properties. Young's modulus and fracture toughness are determined for models with and without vacancies. Fracture toughness and Young's modulus are fundamental indicators of a material's ability to withstand crack propagation and its stiffness, respectively.
DFT, a computational approach, facilitates the analysis of atomic-level interactions within materials. Al2O3, a versatile ceramic with exceptional mechanical characteristics, serves as the subject of investigation.
Through DFT simulations, this research delves into the fracture mechanisms and crack propagation behavior of Al2O3, providing insights into its intrinsic fracture toughness. DFT can predict the formation and behavior of defects and dislocations in the material, which can affect its mechanical properties, including fracture toughness. By integrating DFT results with experimental data, a comprehensive understanding of both fracture toughness and Young's modulus is achieved. The research results provide useful information on the behavior of α-Al2O3 in the presence of vacancies. This study advances insights into Al2O3's crack behavior
and mechanical attributes, informing its application across aerospace, electronics, and manufacturing.
Demonstrating DFT's efficacy in uncovering complex mechanical phenomena, the research guides materials design strategies while forecasting employment opportunities in cutting-edge materials science. Słowa kluczowe: Crack,
Al2O3,
Fracture toughness,
DFT Afiliacje autorów:
Fathalian M. | - | IPPT PAN | Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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4. |
Postek E., Pietras D.♦, Guhathakurta J.♦, Kruszka L.♦, Grążka M.♦, Sadowski T.♦, Experimental testing and numerical modelling of impacts in interpenetrated composite,
ICCSE3, 3rd International Conference on Computations for Science
and Engineering, 2023-08-20/08-23, Neapol (IT), pp.19-20, 2023Streszczenie:
The interpenetrating composites consist of a scaffold and metallic matrix, which fills it being introduced under pressure. The scaffold is usually crushable. In our case, the SiC material stands for the skeleton, while the AlSi12 alloy is the matrix. Both materials are crushable. The SiC phase is brittle throughout the loading process, but the AlSi12 alloy is brittle during the elastic phase; then, its behaviour becomes viscous-plastic. The presentation concerns the experimental testing and simulations of the impact and fragmentation of metal matrix composite - AlSi12/SiC. The numerical model of the internal structure is created based on CT scanning. The microstructure of the composite is complex and consists of a metallic phase (85%), ceramic SiC skeleton, porosity, and a system of not perfect interfaces. The impacts are realized in the following few scenarios. The exemplary scenario is realized by imposing the initial conditions on the sample that hits a hard elastic barrier. The second one corresponds to SHPB experiments. The last one is the hitting of an elastic impactor against the sample. The influence of the impact velocities and material parameters of the phases on the failure modes is observed. Previously, analyses of the modes of loading application on the micromechanical failure of metal matrix composite were analysed in [1, 2]. An analysis of the empty SiC scaffolds is presented in [3]. The proposed finite element model of the AlSi12/SiC composite behaviour describing gradual degradation under impact loading was tested for different scenarios of hitting. In all cases, the growth of damage in the composite is very realistic. These results lead to the conclusion the proposed finite element model is very effective.
Acknowledgement: The results presented in this paper were obtained within the framework of research grant No. 2019/33/B/ST8/01263 financed by the National Science Centre, Poland. The numerical analyses were done in the ICM UW in Warsaw and in CI TASK in Gdańsk, Poland.
References:
[1] Postek, E. and Sadowski, T. Distributed microcracking process of WC/Co cermet under dynamic impulse compressive loading. Compos. Struct. (2018) 194: 494-508.
[2] Postek, E. and Sadowski, T. Qualitative comparison of dynamic compressive pressure load and impact of WC/Co composite. Int. J. Refract. Hard. Met. (2018) 77: 68-81.
[3] Postek, E., Sadowski, T. and Bieniaś, J. Simulation of impact and fragmentation of SiC skeleton, Phys. Letters (2021) 24:578-587.
Słowa kluczowe: Cermets, Interpenetration, Impact, Viscoplasticity, Peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Pietras D. | - | Lublin University of Technology (PL) | Guhathakurta J. | - | CT-LAB Stuttgart (DE) | Kruszka L. | - | Military University of Technology (PL) | Grążka M. | - | Military University of Technology (PL) | Sadowski T. | - | Lublin University of Technology (PL) |
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5. |
Postek E., Sadowski T.♦, Tahani M., Guhathakurta J.♦, A Numerical Model of Interpenetrated Composite Including Interface Properties,
USNCCM17, 17th U.S. National Congress on Computational Mechanics, 2023-07-23/07-27, Albuquerque, New Mexicom (US), pp.738-738, 2023Streszczenie: Advanced multiphase ceramic composites (MCCs) are employed in several modern industrial sectors, for example, aerospace, automotive or energy. The composites are used when extreme conditions like variable loads, impact loads or thermal shocks are expected.
The presentation deals with examples of interpenetrated composites (IPCs). The previous analyses of the composite materials showed the significance of the interface between the phases for the loading resistance of the material [1,2]. The interface forming is affected by the diffusion of the materials. The effect of diffusion of the phases is presented in [3]. An attempt to include the mechanical properties of the interface based on atomistic simulations is given in the presentation.
An analysis of samples of IPC based on SiC ceramic skeleton and an aluminium alloy under impact is performed. The structure of the material is obtained with CT scans. The numerical model considers the properties of the interfaces between the phases. It has been noted that the interface properties are a significant feature of the materials.
Acknowledgement: Grant from National Scientific Committee (PL) UMO-2019/33/B/ST8; Polish National Agency for Academic Exchange (NAWA) [BPN/ULM/2021/1/00115/U/DRAFT/00001].
Calculations: PL-GRID: CYFRONET, Krakow, Poland. ICM at the University of Warsaw, Poland and TASK, Gdansk, Poland.
References
[1] Felten, F., Schneider, G. and Sadowski T. Estimation of R-curve in WC/Co cermet by CT
test. Int. J. Refract. Hard. Met. (2008) 26: 55-60.
[3] Postek, E. and Sadowski, T. Qualitative comparison of dynamic compressive pressure load
and impact of WC/Co composite. Int. J. Refract. Hard. Met. (2018) 77: 68-81.
[3] Tahani M., Postek E. and Sadowski T. Molecular Dynamics Study of Interdiffusion for Cubic and Hexagonal SiC/Al Interfaces, Crystals (2023) 13(1):1-15.
Słowa kluczowe: Metal Matrix Composites,
Cohesive law,
Interface modelling,
Diffusion,
Molecular dynamics,
Finite elements Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) | Tahani M. | - | IPPT PAN | Guhathakurta J. | - | CT-LAB Stuttgart (DE) |
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6. |
Tahani M., Postek E., Sadowski T.♦, Diffusion effect on the cohesive zone model of SiC/Al interface using atomistic simulations,
COMPLAS 2023, XVII International Conference on Computational Plasticity. Fundamentals and Applications, 2023-09-05/09-07, Barcelona (ES), pp.1, 2023Streszczenie: Metal matrix composites (MMCs) are materials consisting of a metal matrix reinforced often with ceramic to improve the properties of the base metal. MMCs are used in a wide range of applications due to their unique combination of high strength, stiffness, and wear resistance with relatively low weight.
It is well recognized that the interface in composites plays a crucial role in transferring the load efficiently from the matrix to the reinforcement. Hence, to predict the overall mechanical properties of MMCs, it is essential to evaluate the interface strength. In this study, the C- and Si-terminated hexagonal and cubic SiC/Al interfaces are studied. The molecular dynamics (MD) simulation is used as a virtual environment to obtain this relation because it is challenging to determine it from experimental results. The equivalent mechanical properties of the interface are characterized by a cohesive zone model based on the traction-separation relation obtained from MD simulations. SiC/Al composites are created using high-temperature techniques that result in a fuzzy interface due to the diffusion of atoms [1]. In this research, the effect of diffusion on the traction-separation relation in mode I fracture is examined. The systems are heated to 2000 K and then cooled to 300 K. Young's modulus of samples after atom diffusion is found to be about 25% lower than those before atom diffusion, but the work of separation is found to increase by at least 40% following the heating of the system and diffusion. This finding demonstrates that diffusion significantly increases the fracture energy of SiC/Al composites. Furthermore, following system heating and diffusion of atoms, the C-terminated samples are found to have higher work of separation than the Si-terminated ones.
Acknowledgments: We acknowledge the National Science Centre, grant No. UMO 2019/33/B/ST8/01263. The calculations were performed at the PLGrid – Academic Computer Centre Cyfronet in Krakow, Academic Computer Centre in Gdańsk, Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw, Poland.
REFERENCE
[1] Tahani M., Postek E., Sadowski T., Molecular dynamics study of interdiffusion for cubic and hexagonal SiC/Al interfaces, Crystals, Vol. 13 (1), 46, 2023.
Słowa kluczowe: Metal Matrix Composite,
Cohesive zone,
Diffusion,
Molecular dynamics Afiliacje autorów:
Tahani M. | - | IPPT PAN | Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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7. |
Tahani M., Postek E., Sadowski T.♦, Molecular dynamics simulations of the interdiffusion at α-Al2O3/AlSi12 interface,
KomPlasTech 2023, XXVII Conference on Computer Methods in Materials Technology, 2023-03-05/03-08, Zakopane (PL), pp.1-4, 2023Streszczenie: Metal matrix composites (MMC) are used more and more in the aerospace, automotive, and bio-
-medical industries because of their high strength-to-weight ratio, high stiffness, and outstanding wear resistance. Aluminium, titanium, and magnesium are the most preferred matrix materials, whereas alumina and silicon carbide are the most used reinforcing elements for these composites. The overall mechanical and failure properties of MMCs depend on the mechanical properties of the constituents and the nature of the interface. The characteristics of the interface must be understood because they have the potential to significantly alter the properties of MMCs. The interface between phases is a fuzzy region because of diffusion. To this end, it is necessary to look into the diffusion between the two phases as the first step for determining the cohesive zone model of the interface.
In this study, AlSi12 metal alloy as matrix material reinforced with α-Al2O3 is considered. AlSi12
is an aluminium alloy that contains 12 wt.% silicon with excellent thermal conductivity, good corrosion resistance, and low density. The composite can be used in various high-temperature applications such as furnace linings, engine parts, and aerospace components. It is worth noting that the properties and performance of the composite will depend on the processing conditions, microstructure, the proportion of the components, and the interface’s characteristics.
The investigation carried out by Milas et al. [1] regarding the diffusion of Al, O, Pt, Hf, and Y atoms
on α-Al2O3(0001) can be mentioned as an illustration of research that has been published in the literature.
To the authors’ knowledge, no studies have been done on α-Al2O3/AlSi12 diffusion couple. To this end, the self-diffusion and interdiffusion at the interface are investigated in this research by heating the system to the desired temperature. The effect of annealing temperature and annealing time are studied on the diffusion zone and interdiffusion coefficients. The thickness of the diffusion zone and the interdiffusion coefficients are found to increase as expected with increasing annealing temperature and time. Słowa kluczowe: Self-diffusion, Interdiffusion, Metal-ceramic composite, Al2O3/AlSi12 interface;
Molecular dynamics method Afiliacje autorów:
Tahani M. | - | IPPT PAN | Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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8. |
Postek E., Pietras D.♦, Guhathakurta J.♦, Sadowski T.♦, Numerical model of impact and fragmentation of interpenetrated composite,
ICCSE, 2nd International Conference on Computations for Science and Engineering, 2022-08-30/09-02, Rimini (IT), pp.24-24, 2022Streszczenie: The interpenetrating composites consist of a scaffold and metallic matrix, which fills it being introduced under pressure. The scaffold is usually crushable. In our case, the SiC material stands for the skeleton, while the AlSi12 alloy is the matrix. Both materials are crushable. The SiC phase is brittle throughout the loading process, but the AlSi12 alloy is brittle during the elastic phase; then, its behaviour becomes viscous-plastic. The presentation concerns the simulations of impact and fragmentation of metal matrix composite - AlSi12/SiC. The numerical model of the internal structure is created based on CT scanning. The microstructure of the composite is complex and consists of metallic phase (85%), ceramic SiC skeleton, porosity, and system of not perfect interfaces. The impacts are realized in the following few scenarios. The exemplary scenario is realized by imposing the initial conditions on the sample that hits a hard elastic barrier. The second one corresponds to SHPB experiments. The last one is the hitting of an elastic impactor against the sample. The influence of the impact velocities and material parameters of the phases on the failure modes is observed. Previously, analyses of the modes of loading application on the micromechanical failure of metal matrix composite were analysed in [1, 2]. An analysis of the empty SiC scaffolds is presented in [3]. The proposed finite element model of the AlSi12/SiC composite behavior describing gradual degradation under impact loading was tested for different scenarios of hitting. In all cases, the growth of damage in the composite is very realistic. These results lead to the conclusion the proposed finite element model is very effective. Acknowledgment: The results presented in this paper were obtained within the framework of research grant No. 2019/33/B/ST8/01263 financed by the National Science Centre, Poland. The numerical analyses were done in the ICM UW in Warsaw, CYFRONET AGH in Krakow and in CI TASK in Gdańsk, Poland. Słowa kluczowe: Impact, Interpenetrated Ceramic Composites, Fragmentation, Peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Pietras D. | - | Lublin University of Technology (PL) | Guhathakurta J. | - | CT-LAB Stuttgart (DE) | Sadowski T. | - | Lublin University of Technology (PL) |
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9. |
Postek E., Sadowski T.♦, Numerical Modelling of Influence of Interface Properties on the Performance of Interpenetrated Composites,
WCCM-APCOM YOKOHAMA2022, 15th World Congress on Computational Mechanics and 8th Asian Pacific Congress on Computational Mechanics, 2022-07-31/08-05, Jokohama (JP), pp.1457-1457, 2022Streszczenie: Multiphase Ceramic Composites (CCs) are used in several modern industries like aerospace, automotive, nuclear power, or defense. They are used in the situation of expected extreme loads like variable loads or impacts. The interpenetrating composites (IPCs) is a class of composites that are defined by the technological process. The IPCs consist of a crushable skeleton and a metallic phase introduced into the skeleton under pressure. The resulting material combines the features of the skeleton and the filling metal. Earlier analyses of the composite systems showed the significance of the interface between the particular phases [1, 2, 3] for the overall performance of the samples and its load-carrying capacity. An attempt to include the mechanical properties based on atomistic simulations is shown. An analysis of samples of IPC based on SiC ceramic skeleton and an aluminum alloy under impact conditions is performed. The 3D structure of the sample is obtained with CT scans. The numerical model takes into account the properties of the interfaces between the phases. It has been noted that the interface properties are a significant feature of the materials and the resulting numerical model. Słowa kluczowe: Metal-ceramic Interpenetrating Phase Composites,
Impact Loading,
Peridynamics,
Finite Element Method,
Atomistic Simulations Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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10. |
Postek E., Sadowski T.♦, Kruszka L.♦, Grążka M.♦, Guhathakurta J.♦, Fikus B.♦, Numerical modelling and experimental observation of ballistic penetration process in two-phase metal/ceramic composites,
ESMC 2022, 11th European Solid Mechanics Conference, 2022-07-04/07-08, Galway (IE), pp.1, 2022Streszczenie: Ceramic two-phases composites are used in such industries as the armaments industry, aviation, automotive, nuclear power, and space exploration. In several areas, they stand as the source of technological progress. The material is often subjected to extreme loads, such as variable dynamic loads and high temperatures. The paper presents experimental investigations of ballistic impact on ceramic /metal composites. The internal structure of the novel material consists of ceramic foam made of SiC and filled with Al alloy. The experiment was performed using the ballistic stand and spherical impactor of diameter 5 mm and mass 0.5 g. The impactor hit the sample of diameter 30 mm and thickness 4 mm with a velocity of 600 m/s. Fig. 1 presents crater after impact and defragmented sample. The numerical analysis of the fragmentation process was performed using the finite element method. The internal structure of the composite was assessed using micro-CT selecting both phases, i.e., ceramic foam and AL alloy. The phases are joined by a continuous very small thickness interface. The numerical calculations allow for the description of the whole degradation process of the analysed interpenetrating composite up to the final failure by fragmentation and confirm the novel applicability of the material as a protective layer against the high-velocity impact. Acknowledgement The work has been performed under the research grants 2019/33/B/ST8/01263, National Science Centre, Poland. The analyses were done in the ICM UW in Warsaw and in CI TASK in Gdańsk, Poland. References [1] T. Ohji and M. Singh, Engineered Ceramics: Current Status and Future Prospects: Wiley, 2015. Słowa kluczowe: two-phase metal/ceramic composites, penetration experiments, numerical modelling Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) | Kruszka L. | - | Military University of Technology (PL) | Grążka M. | - | Military University of Technology (PL) | Guhathakurta J. | - | CT-LAB Stuttgart (DE) | Fikus B. | - | inna afiliacja |
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11. |
Pietras D.♦, Sadowski T.♦, Postek E., Boniecki M.♦, Tarasiuk J.♦, Badania eksperymentalne kompozytów AlSi/SiC w stanach jednoosiowego rozciągania i ściskania,
PLASTMET 2021, XII Konferencja Naukowa, Zintegrowane Studia Podstaw Deformacji Plastycznej Metali, 2021-11-23/11-26, Łańcut (PL), pp.54-55, 2021Streszczenie: W pracy przedstawiono badania eksperymentalne kompozytów ceramicznych infiltrowanych poddanych działaniu obciążeń mechanicznych. Rozpatrywany typ kompozytów wytwarzany jest z pianki ceramicznej typu SiC, która wypełniona jest stopem AlSi. Ten typ zaawansowanego kompozytu jest stosowany w przemyśłe kosmicznym, lotniczym i samochodowym.
Przeprowadzono obserwacje mikroskopowe struktury badanych kompozytów oraz pianki ceramicznej, wykonano skany micro-CT.
Odpowiedź na obciążenia dynamiczne zbadano prętem Hopkinsona używając próbek krępych.
Uzyskane wyniki pokazują postacie zniszczenia próbek cylindrycznych i beleczek. Wskazują one na istotny wpływ szkieletu ceramicznego na zachowanie kompozytu.
The experimental testing of interpenetrating composite was presented for uniaxial compression or tension. The analysed composite was manufactured using SiC ceramic foaminfiltrated by an alloy of AlSi. This type of composites is used in cosmic, aerospace, or automotive idustries.
The response of the rested material waas investigated using stocky samples in the Hopkinson bar device.
The obtained results exhibit different modes of fracture of cylindrical and beam samples. They indicate the substantial influence of the ceramic skeleton on the behaviour of the composite under the dynamic loading.
Słowa kluczowe: Kompozyty metalowo ceramiczne, kompozyty infiltrowane, skany CT, pręt Hopkinsona, dynamika, pękanie zniszczenie,
Metal matrix composites, infiltrated composites, CT scanning, Hopkinson bar, dynamics, fracture, failure Afiliacje autorów:
Pietras D. | - | Lublin University of Technology (PL) | Sadowski T. | - | Lublin University of Technology (PL) | Postek E. | - | IPPT PAN | Boniecki M. | - | Institute of Electronic Materials Technology (PL) | Tarasiuk J. | - | inna afiliacja |
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12. |
Postek E., Sadowski T.♦, Pietras D.♦, Uderzenie interpenetrowanego kompozytu Al/SiC,
PLASTMET 2021, XII Konferencja Naukowa, Zintegrowane Studia Podstaw Deformacji Plastycznej Metali, 2021-11-23/11-26, Łańcut (PL), pp.57-58, 2021Streszczenie: Kompozyty ceramiczne infiltrowane (IPC) znajdują zastosowanie w kilku strategicznie ważnych gałęziach przemysłu. Przykładami są przemysł motoryzacyjny, energetyka jądrowa lub przemysł kosmiczny. Badany kompozyt składa się ze szkieletu SiC i wypełnienia stopem aluminium. Próbki poddawane są mechanicznemu obciążeniu udarowemu. Dla materiału kruchego zastosowany został konstytutywny model uszkodzeń zaś materiał wypełnienia jest modelowany jako sprężysto-plastyczny. Do obliczeń zastosowana została perydynamika. Ważnym parametrem jest uwzględniana w obliczeniach odporność na pękanie materiału szkieletu. Zbadane zostało zachowanie próbki dla małych i dużych prędkości uderzenia. Ostatnia uwaga dotycząca metody peridynamiki dotyczy jej praktycznego wykorzystania, a mianowicie wyniki badań numerycznych potwierdzają stosowalność metody do oceny materiałów IPC, mimo że metoda ta powinna być używana przy zastosowaniu masowo zrównoleglonego oprogramowania i nowoczesnych klastrów komputerowych by uzyskiwać wyniki w rozsądnym czasie.
Infiltrated ceramic composites (IPCs) are used in several strategically important
industries. Examples are the automotive industry, nuclear Energy, or the space industry. The
tested composite consists of a SiC skeleton and an aluminum alloy filling. The samples are
subjected to impact loading. For the brittle material, a constitutive model of damage has been
used, and the filling material is modeled as elastic-plastic. Peridynamics was used for the
calculations. A final remark considering the peridynamics method concerns the practical use of
peridynarnics, namely, the results of the numerical studies confirm the feasibility of the method
for evaluation of the IPCs materials even though it should be used massively parallelized
software and up-to-date computer clusters to obtain results within a reasonable time.
Słowa kluczowe: kompozyty metalowo-ceramiczne, kompozyty interpenetrowane, uderzenie, perydynamika,
metal matrix composites, interpenetrated composites, impact, peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) | Pietras D. | - | Lublin University of Technology (PL) |
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13. |
Postek E., Sadowski T.♦, Compressive impact of SiC foam,
DSTA 2021, 16th INTERNATIONAL CONFERENCE Dynamical Systems
Theory and Applications, 2021-12-06/12-09, Łódź (PL), DOI: 10.34658/9788366741201, pp.444-445, 2021Streszczenie: The silicon carbide (SiC) can be used for its foam production. It is used for infiltrated
composites fabrication. In this paper, a problem of an impact of a steel plate travelling
with high velocity hitting a silicon carbide sample (SCF) is considered. The presentation concerns
the modes of failure and degradation. Słowa kluczowe: SiC, silicon carbide foam, impact, compression, peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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14. |
Postek E., Sadowski T.♦, Bieniaś J.♦, Boniecki M.♦, Dynamic impact of a ceramic skeleton of interpenetrating phase composites,
ICTAM2021, 25th International Congress of Theoretical and Applied Mechanics, 2021-08-22/08-27, Mediolan (virtual) (IT), pp.308-309, 2021Streszczenie: The paper presents the modelling of a ceramic foam that works as a skeleton of Interpenetrating Phase Composites (IPCs) before filling the preforms. The preforms are made of SiC or Al2O3. A dynamic analysis of the impact of such skeletons against the rigid surface is performed. The results of the quasi-static analysis will serve as a reference to the dynamic analyses. The analysis of the IPCs skeleton is performed due to evaluation of the role of the skeleton in a final product that is the filled IPCs. Słowa kluczowe: interpenetrating phase composites, metal-matrix composites, ceramic skeleton, peridynamics, high-performance computing Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) | Bieniaś J. | - | inna afiliacja | Boniecki M. | - | Institute of Electronic Materials Technology (PL) |
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15. |
Sadowski T.♦, Postek E., Pietras D.♦, Gieleta R.♦, Kruszka L.♦, Non-linear dynamic and quasi-static responses of two-phase ceramic matrix and metal matrix composites subjected to compression and degradation,
ICTAM2021, 25th International Congress of Theoretical and Applied Mechanics, 2021-08-22/08-27, Mediolan (virtual) (IT), pp.257-258, 2021Streszczenie: The paper presents modelling and experimental testing of non-linear degradation processes developing in the two-phase ceramic matrix (CMCs) and metal matrix composites (MMCs) subjected to quasi-static and dynamic compressive loading. Modelling was performed by a multiscale approach using both: (1) analytical and (2) numerical methods and selected Representative Volume Elements (RVE) based on SEM observations of composites. Both quasi-static and dynamic experimental tests were done applying standard MTS (100 kN) servo-hydraulic machine and Split Hopkinson Pressure Bar (SHPB) stand for impact tests with loading velocities 20 – 30 m/s. As a result, we observed for CMCs in quasi-static loading failure mode by splitting of cylindrical samples, whereas for impact loading dynamic crushing process took place. Słowa kluczowe: metal-matrix composites, dynamic testing, Split Hopkinson Pressure Bar, peridynamics Afiliacje autorów:
Sadowski T. | - | Lublin University of Technology (PL) | Postek E. | - | IPPT PAN | Pietras D. | - | Lublin University of Technology (PL) | Gieleta R. | - | inna afiliacja | Kruszka L. | - | Military University of Technology (PL) |
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16. |
Postek E., Nowak Z., Pęcherski R., Viscoplastic material with shear bands effect,
USNCCM16, 16th U.S. National Congress on Computational Mechanics, 2021-07-25/07-29, Chicago (US), pp.1, 2021Streszczenie: The paper‘s subject is the formulation accounting for shear bands in fine-grained metals [2] in terms of peridynamics. The formulation stands for an extension of the viscoplasticity model [1]. Several experimental investigations prove that plastic deformation's main mechanism is developing shear bands in prevailing cases. An influence of the rapid shear banding generation on the cumulated plastic strain field is investigated. The model is valid for finite strains. The primary interest is focused on impact analysis. The numerical models of the Taylor bar are shown. A complex structure, such as copper open-cell foam, were presented in [3]. The numerical examples given in [3] are enriched with the newly developed formulation.
Słowa kluczowe: viscoplasticity, shear bands, peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Nowak Z. | - | IPPT PAN | Pęcherski R. | - | IPPT PAN |
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17. |
Sadowski T.♦, Postek E., Pietras D.♦, Boniecki M.♦, Szutkowska M.♦, Description of quasi-static and dynamic damage processes in 2-phase ceramic matrix and metal matrix composites reinforced by ceramic grains,
ACE-X 2021, 14th INTERNATIONAL CONFERENCE ON ADVANCED COMPUTATIONAL
ENGINEERING AND EXPERIMENTING - ACE-X 2021, 2021-07-04/07-08, St. Julian's (MT), pp.9-10, 2021Streszczenie: Quasi-static degradation of brittle composites exhibits different mechanical responses under uniaxial tension and uniaxial compression. In this paper, we analysed cracking processes and failure under quasi-static loading of 2 phase ceramic material made of alumina and zirconia mixture, subjected to tension and compression. Constitutive modelling of two-phase ceramic composites obeys description of (1) elastic deformations of initially porous material, (2) limited plasticity and (3) cracks initiation and propagation. Modelling of polycrystalline ceramics at the mesoscopic level under mechanical loading is related to the analysis of a set of grains, which create a so-called Representative Volume Element (RVE). The basic elements of the defect structure inside polycrystal are: micro- and meso-cracks, kinked and wing cracks. To get the macroscopic response of the material one can calculate averaged values of stress and strain over the RSE with the application of an analytical approach. The dynamic degradation process was illustrated for 2 phase ceramic matrix composite and cermet, which was subjected to short compressive impulse. The pulse duration was 10-7s and the applied pressure level - 480 MPa. In the proposed, more advanced finite element formulation of the cermet behaviour is was necessary to take into account the following data and phenomena revealing inside of the RVE: (1) spatial distribution of the cermet constituents, (2) system of grain boundaries/binder interfaces modelled by interface elements, (3) rotation of brittle grains. The cermet response due to pulse loading is significantly different in comparison to the quasi-static behaviour, i.e. the stress distributions and microcracking processes are quite different. Słowa kluczowe: cermets, dynamic behaviour, brittle cracking Afiliacje autorów:
Sadowski T. | - | Lublin University of Technology (PL) | Postek E. | - | IPPT PAN | Pietras D. | - | Lublin University of Technology (PL) | Boniecki M. | - | Institute of Electronic Materials Technology (PL) | Szutkowska M. | - | Institute of Advanced Manufacturing Technology (PL) |
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18. |
Sadowski T.♦, Pietras D.♦, Postek E., Experimental testing and of modelling of gradual degradation of Al2O3/ZrO2 ceramic composite under slow and high strain rates,
ICCS23, ICCS23 - 23rd International Conference on Composite
Structures & MECHCOMP6 - 6th International Conference
on Mechanics of Composites, 2020-09-01/09-04, Porto (PT), pp.143-143, 2020Streszczenie: Gradual degradation of brittle composites exhibits different mechanical response under uniaxial tension and uniaxial compression. In this paper, we analysed cracking processes and failure under quasi-static loading of 2 phase ceramic material made of Al2O3 and ZrO2 mixture, subjected to tension and compression. Constitutive modelling of two-phase ceramic composites obeys description of (1) elastic deformations of initially porous material, (2) limited plasticity and (3) cracks initiation and propagation. Modelling of polycrystalline ceramics at the mesoscopic level under mechanical loading is related to the analysis of a set of grains, i.e. Representative Volume Element (RVE). The basic elements of the defect structure inside polycrystal are micro-cracks and meso-cracks, kinked and wing cracks. To get a macroscopic response of the material one can calculate averaged values of stress and strain over the RSE with an application of the analytical approach. High strain rate degradation process was illustrated for Al2O3/ZrO2 composite, which was subjected to short compressive impulse. The pulse duration was 10-7s. In the proposed more advanced finite elements formulation it was necessary to take into account the following data and phenomena appearing inside of the RVE: (1) spatial distribution of the composite constituents, (2) system of grain boundaries/binder interfaces modelled by interface elements, (3) rotation of brittle grains. The numerical model of gradual degradation of the Al2O3//ZrO2 composite response due to pulse compressive loading presents correctness and capability of the proposed FEM approach. Słowa kluczowe: brittle composites, representative volume element, degradation, damage, peridynamics Afiliacje autorów:
Sadowski T. | - | Lublin University of Technology (PL) | Pietras D. | - | Lublin University of Technology (PL) | Postek E. | - | IPPT PAN |
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19. |
Postek E., Sadowski T.♦, Impact model of two-phase composites,
DynaMAT, The 13th WORKSHOP on DYNAMIC BEHAVIOR OF MATERIALS AND ITS APPLICATIONS IN INDUSTRIAL PROCESSES, 2019-04-17/04-19, Nicosia (CY), pp.1-2, 2019Streszczenie: Assessment of impact techniques is given in [1]. A basic model of a two-phase material is presented in [2]. Two-phase composites are of vital applications in modern technology, for example cutting tools, implants, jet engines. Examples of such materials are WC/Co and Al2O3/ZrO2. Highly innovative technologies need applications of modern polycrystalline materials. The manufactured polycrystalline materials are planned to have controlled internal structure. However, even though the process is controlled the internal structure can be still complex due to engineering requirements. The novel multiphase materials possess different internal geometries, for example (i) with regular of disordered internal structures with introduced fibers, particles or nanoparticles (ii) with a functional gradation of mechanical or physical properties (iii) fabricated as regular of irregular layered materials structures. The analyses of modern composites require efficient computational methods and codes. The new method that has been developed mostly in the last ten years is peridynamics [3,4]. The developments resulted in a highly parallelised code [5] that we use in our analysis. We further investigate the model of cermet that has been developed with the finite element method [6, 7, 8]. The primary goal of the paper is to investigate the previously formulated models of the twophase composite under impacts. We have taken into account the spatial distribution of cermet phases, grain/binder interfaces modelled by interface elements and movement of brittle grains. We analyse a sample of the material that can be considered as Representative Volume Element RVE and do verification of the material properties of the RVE by multiplication of the elementary sample with complex geometry [9]. In Fig. 1, we illustrate an outline of the analysis. It is an Al2O3/ZrO2 polycrystal that hits a rigid obstacle with a velocity V. In this case, the velocity of the impactor is 100 m/s. We observe the damage development in the interfaces calculated with finite element and PD methods at time 10 ns. Further on, we consider damage models [10], elastic-plastic [11] and elastic-viscous-plastic models [12]. Słowa kluczowe: two phase composites, damage, elasoplasticity, impact, peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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20. |
Sadowski T.♦, Postek E., Pietras D.♦, Boniecki M.♦, Szutkowska M.♦, Modelling of Quasi-static and Dynamic Damage Process in Ceramic Matrix Composites,
MECHCOMP 2019, 5th International Conference on Mechanics of Composites, 2019-07-01/07-04, Lizbona (PT), pp.80-81, 2019Streszczenie: Quasi-static degradation of brittle composites exhibits different mechanical response under uniaxial tension and uniaxial compression. In this paper we analysed cracking processes and failure under quasi-static loading of 2 phase ceramic material made of alumina and zirconia mixture, subjected to tension and compression. Constitutive modelling of two phase ceramic composites obeys description of: (1) elastic deformations of initially porous material, (2) limited plasticity and (3) cracks initiation and propagation. Modelling of polycrystalline ceramics at mesoscopic level under mechanical loading is related to analysis of a set of grains, which create so called Representative Volume Element (RVE). The basic elements of the defect structure inside polycrystal are: micro- and meso-cracks, kinked and wing cracks. To get macroscopic response of the material one can calculate averaged values of stress and strain over the RSE with application of analytical approach. Dynamic degradation process was illustrated for 2 phase ceramic matix composite and cermet, which was subjected to short compressive impulse.
The pulse duration was 10-7s and the applied pressure level - 480 MPa. In the proposed more advanced nite elements formulation of the cermet behaviour is was necessary to take into account the following data and phenomena revealing inside of the RVE: (1) spatial distribution of the cermet constituents, (2) system of grain boundaries/binder interfaces modelled by interface elemnets, (3) rotation of brittle grains. The cermet response due to pulse loading is signifcantly different in comparison to the quasistatic behaviour, i.e. the stress distributions and microcracking processes are quite different. Słowa kluczowe: brittle composites, damage, quasi-static behaviour, dynamics, RVE Afiliacje autorów:
Sadowski T. | - | Lublin University of Technology (PL) | Postek E. | - | IPPT PAN | Pietras D. | - | Lublin University of Technology (PL) | Boniecki M. | - | Institute of Electronic Materials Technology (PL) | Szutkowska M. | - | Institute of Advanced Manufacturing Technology (PL) |
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21. |
Postek E., Pęcherski R.B., Nowak Z., Viscoplasticity effect during impact of metallic foams,
CCAM & 3D-Printing, Collaborative Conference on Advanced Materials, 2019-08-26/08-30, St. Julian's (MT), pp.16-17, 2019Streszczenie: In the last 20 years, a new rapidly developing method is applied to calculations of solid mechanics problems, [1]. It is a non-local method. The predecessors of the method that have been applied to crystals were developed in [2] and [3]. In the presentation, we show an application of the method for the evaluation of the viscoplasticity effects [4, 5] in the copper foams. The oxygen free high conductivity copper (OHFC) can be applied to produce the open-cell multifunctional structures, for example, heat exchangers, heat capacitors, using additive manufacturing [6]. We use the highly parallelized program Peridigm for the analysis, [7].
Figure 1(a) shows an exemplary impacting foam sample attacking with a velocity of 20 m/s an elastic block. The highest plastic strains are in the case of ideally elastic-plastic case (b). The equivalent plastic strains are higher when neglecting the strain rate hardening effects (d) than including both strain hardening and strain rate hardening effects (c). We provide dependences of the equivalent plastic strains on impact velocities and strain rate hardening exponents.
Literature;
1. S.A. Silling, Journal of Mechanics and Physics of Solids, 48, 175 (2000).
2. D. Rogula, Nonlocal theory of material media (Springer), 123 (1982).
3. A. Kunin, Elastic media with microstructure, one dimensional models (Springer), (1982).
4. J.A. Mitchell, A Nonlocal, Ordinary, State-Based Plasticity Model for Peridynamics (SANDIA ), (2011).
5. J.T. Foster, S.A. Silling, W.W. Chen, International Journal for Numerical Mechods in Engineering, 81,1242 (2010).
6. R.B. Pęcherski, M. Nowak, Z. Nowak, International Journal for Multiscale Computational Engineering, 15, 431 (2017).
7. M.L. Parks, D.J. Littlewood, J.A. Mitchell, S.A. Silling, Peridigm Users’ Guide (SANDIA), (2012). Słowa kluczowe: metallic foams, composites, impact loading, peridynamics, parallel computing Afiliacje autorów:
Postek E. | - | IPPT PAN | Pęcherski R.B. | - | IPPT PAN | Nowak Z. | - | IPPT PAN |
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22. |
Postek E., Scheider Y.♦, Schmauder S.♦, Impact of WC/Co/diamond sample with peridynamics,
SCFE2019, Supercomputing Frontiers Europe 2019, 2019-03-11/03-14, Warsaw (PL), pp.1-4, 2019Streszczenie: Metal Matrix Composites (MMCs) are widely used in several strategic industrial sectors, such as defense, aerospace, nuclear power plants, space exploration, being the main source of technological progress in the others, for example machining. In this communication, we use meshless method that is peridynamics for simulation of impact of a sample. Peridynamics is a non-local, meshless quite recently formulated method of stress analysis. Nonlocal methods were developed for crystal analysis [1], [2]. The nonlocal methods were generalized on the coupled problems in [3]. The peridynamics was formulated for the first time by Silling [4, 5]. Słowa kluczowe: WC/Co composite, Impact loading, Peridynamics, Numerical model Afiliacje autorów:
Postek E. | - | IPPT PAN | Scheider Y. | - | University of Stuttgart (DE) | Schmauder S. | - | University of Stuttgart (DE) |
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23. |
Postek E., Sadowski T.♦, Boniecki M.♦, Impact of Al2O3/ZrO2 Composite, Qualitative Comparison of Compositions,
RANM2019, Fourth International Conference on Recent Advances in Nonlinear Mechanics, 2019-05-07/05-10, Łódź (PL), pp.226-228, 2019Streszczenie: The ceramic composites Al2O3/ZrO2 are used for different kind of implants since they are nontoxic and nonallergic [1]. The composites of different composition of both compounds are obtained by sintering at the temperature 1600◦C. The amount of zirconia in the composite is normally up to 30% volume. The investigation of such properties like Youngs modulus, toughness and flexural strength is presented in [2]. The properties of ZrO2 compound with stabilization of Y2O3 are described in [3]. Słowa kluczowe: Al2O3/Zr02, composite compositions, impact, peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) | Boniecki M. | - | Institute of Electronic Materials Technology (PL) |
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24. |
Postek E., Pęcherski R.B., Nowak Z., Perydynamiczna symulacja procesów zgniatania otwartokomórkowych pianek miedzianych,
PLASTMET, 11 KONFERENCJA ZINTEGROWANE STUDIA PODSTAW DEFORMACJI PLASTYCZNEJ METALI, 2018-11-27/11-30, Łańcut (PL), pp.120-121, 2018Streszczenie: W ciągu ostatnich dwudziestu lat opracowano nową metodę bezsiatkową znaną jako perydynamika [1]. Metoda ta posługuje się zrównoleglonym kodem obliczeniowym [2]. Przedmiotem badań jest deformacja miedzianej pianki o strukturze otwartokomórkowej poddanej dynamicznemu ściskaniu, Rys. 1.
Model komputerowy szkieletu pianki otrzymano wykorzystując koncepcję materiału wirtualnego przedstawioną w pracy [3]. W zależności od potrzeb wymiary struktury szkieletu pianki można skalować. Materiałem pianki jest miedź beztlenowa o wysokiej przewodności cieplnej (OFHC), wykorzystywana do wytwarzania wielofunkcyjnych struktur komórkowych takich jak wymienniki lub kondensatory cieplne, itp. W obliczeniach zastosowano lepkoplastyczny model materiału szkieletu pianki, a symulacje przeprowadzono dla różnych prędkości uderzenia. Rezultaty metody perydynamiki porównano z obliczeniami MES podobnych problemów ściskania dynamicznego pianki. Obliczenia wykonano w ICM Uniwersytetu Warszawskiego na komputerze CRAY XC-40 oraz na klastrze HP w centrum TASK w Gdańsku. Słowa kluczowe: Obciążenia uderzeniowe, pianka metaliczna, perydynamika Afiliacje autorów:
Postek E. | - | IPPT PAN | Pęcherski R.B. | - | IPPT PAN | Nowak Z. | - | IPPT PAN |
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25. |
Postek E., Sadowski T.♦, Model uderzenia z dużą prędkością płytki wykonanej z kompozytu dwufazowego, początek procesu,
PLASTMET, 11 KONFERENCJA ZINTEGROWANE STUDIA PODSTAW DEFORMACJI PLASTYCZNEJ METALI, 2018-11-27/11-30, Łańcut (PL), pp.122-123, 2018Streszczenie: Materiały metaloceramiczne są często stosowane w elementach, które mogą być poddane uderzeniom. Jednak większość prac dotyczących obciążeń dynamicznych dotyczy kompozytów warstwowych. Techniki oceny obciążeń uderzeniowych dla kompozytów dobrze przedstawione są w pracy [1]. Przykładem kompozytu dwufazowego jest WC/Co. Ten rodzaj kompozytu jest często modelowany jako posiadający sprężysto plastyczne wypełnienie oraz sprężyste ziarna. Powodem tego jest wysoka odporność na zniszczenie materiału WC. Przedstawiamy rozszerzenie wcześniej opracowanych modeli [2], w których zakładana była idealna sprężystość ziaren. W nowym modelu zakładamy możliwość zniszczenia ziaren. Badamy układ, w którym próbka uderza o sztywną ścianę z różnymi prędkościami. Słowa kluczowe: Obciążenia uderzeniowe, węglik wolframu, kompozyt dwufazowy, metoda elementów skończonych Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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26. |
Postek E., Sadowski T.♦, Temperature effect in 2 phase ceramic based composite during impact conditions,
ICCS21, 21st International Conference on Composite Materials, 2018-09-04/09-07, Bologna (IT), DOI: 10.15651/978-88-938-5079-7, pp.100, 2018Streszczenie: Cermet Materials (CM) are often used for manufacturing of different cutting tools. They have very good mechanical, wear and thermal properties. In our opinion, the dynamic load is still not enough thoroughly analysed, and the impact load as well. The tools are subjected to different dynamic effects.We have taken into account complex spatial distribution of cermet phases, grain/binder interfaces modeled by interface elements, possibility of cracks appearance within binders using interface elements as well, and rotation of brittle grains.
The main goal of the presentation is to develop further previously formulated models of two-phase composite [1-4] to capture effects of temperature due to impact. The source of the thermal loading is the conversion of plastic work into heat [5, 6]. The increase of temperature takes place in the Co interfaces. We investigate adiabatic and fully coupled solutions.
We note differences in the behaviour of the samples when the thermal loading is not considered. We have found that the thermal softening effect in the interface material is important as well. We enhance the description of the damage mechanism in the presence of temperature increase.
Acknowledgements
This work was financially supported by Ministry of Science and Higher Education (Poland) within the statutory research (IPPT PAN) and National Science Centre (Poland) project No 2016/21/B/ST8/01027 (Lublin University of Technology). The calculations were done at the Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw, Poland. The licenses for the MSC Patran and Abaqus programs were provided by Academic Computer Centre in Gdańsk, Poland.
References:
[1] Sadowski T, Hardy S, Postek E. Prediction of the mechanical response of polycrystalline ceramics containing metallic intergranular layers under uniaxial tension. Comput Mat Sci 2005;34:46-63.
[2] Sadowski T, Hardy S, Postek E. A new model for the time-dependent of polycrystalline ceramic materials with metallic inter-granular layers under tension. Mat. Sci. Eng. A 2006;424:230-238.
[3] Sadowski T, Postek E, Denis C. Stress distribution due to discontinuities in polycrystalline ceramics containing metallic inter-granular layers. Comput Mat Sci 2007;39: 230-236.
[4] Postek E, Sadowski T. Dynamic pulse sensitivity of WC/Co composite, (accepted in Composite Structures).
[5] Wriggers P, Miehe C, Kleiber M, Simo JC. On the coupled thermomechanical treatment of necking problems via finite element methods. Int. J. Num. Meth. Eng. 1992; 33:869–883.
[6] Rojek J, Onate E, Postek E. Application of explicit FE codes to simulation of sheet and bulk metal forming processes. J. Mat. Proc. Tech. 1998; 80–81: 620–627.
Słowa kluczowe: cermet composites, coupled solutions, thermomechanics Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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27. |
Postek E., Nowak Z., Pęcherski R.B., Impact resistance of crushable foam skeleton,
SolMech 2018, 41st SOLID MECHANICS CONFERENCE, 2018-08-27/08-31, Warszawa (PL), pp.1-2, 2018Streszczenie: The analyses of the modern cellular materials due to complexity of their internal structure require efficient computer methods and codes. The new method that has been developed mostly in the last 10 years is peridynamics [1, 2]. The developments resulted in highly parallelized code [3] that we use in our analysis. The subject of the study are alumina foams produced by gelcasting method. The results of microtomography of alumina foams are used to create the numerical model reconstructing the structure of foam skeleton. The numerical simulations of failure strength under compression for alumina foams are performed. The calculations with use of the numerical model are time consuming. Therefore, the simplified method of the assessment of failure strength is proposed. The 3D model of the foam structure is created. The detailed description of the model generation is presented in Nowak et al. [5]. The numerical models of real Al2O3 foam with porosity 96 %, and discussion of theirs mechanical properties have been presented. The method of the assessment of failure strength of real alumina foam produced by the gelcasting is proposed. We attempt to present the mechanism of damaging of a crushable foam under impact. Słowa kluczowe: foams, damage, impact, peridynamics Afiliacje autorów:
Postek E. | - | IPPT PAN | Nowak Z. | - | IPPT PAN | Pęcherski R.B. | - | IPPT PAN |
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28. |
Postek E., Sadowski T.♦, Temperature effects during impact of WC/Co composites,
SolMech 2018, 41st SOLID MECHANICS CONFERENCE, 2018-08-27/08-31, Warszawa (PL), pp.1, 2018Streszczenie: Generally, the papers on dynamic loading of composites more focus on the layered composites, for example [1]. High attention is paid to blast load. However, in our opinion, the process of impact a gap for analysis of WC/Co composite during impact conditions. During impact of WC/Co composite objects and the other composites with metallic binder heat of plastic work is generated. If the process is fast enough the problem can be treated as adiabatic. However, more common situation is slower process when the heat is generated in metallic interfaces and the neighbouring grains are heated due to conduction. The process should be rather considered as coupled [2]. We developed our model of WC/Co composite towards impact load, [3]. Słowa kluczowe: thermomechanics, coupled problems, composites Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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29. |
Postek E., Generation of a tumor model,
Supercomputing Frontiers Europe wraz z XX Sesją Sprawozdawczą Użytkowników KDM, 2018-03-12/03-16, Warszawa (PL), pp.1, 2018Streszczenie: The physical environment of living cells and tissues, and more particularly their mechanical interaction with it, plays a crucial regulatory role in their biological behaviour such as cell differentiation, apoptosis, proliferation, tissue growth, remodelling, tumor growth, etc. However, the way that mechanical forces at the cellular level (i) influence the cell functions and (ii) govern the behaviour of cell assemblies as well as their development, remains unclear and hard to model. First of all, we investigate a tissue growth model. The model is generated with PhysiCell [1, 2]. Słowa kluczowe: computational biology, tumor growth Afiliacje autorów:
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30. |
Postek E., Sadowski T.♦, Impact modelling of cerment composite,
The 7th International Conference on Advanced Materials and Structures, 2018-03-28/03-31, Timisoara (RO), pp.111, 2018 | |
31. |
Postek E., Sadowski T.♦, Impact Models of WC-Co Composite,
CERMODEL 2017Modelling and Simulation Meet Innovation in Ceramics Technology, 2017-07-26/07-28, Trento (IT), pp.1-1, 2017 | |
32. |
Postek E., Dubois F.♦, Mozul R.♦, Canadas P.♦, Modelling of a Collection of Non-Rigid Particles with Smooth Discrete Element Method,
SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), pp.1, 2016Słowa kluczowe: cell mechanics, smooth discrete element method, finite element method, finite motions Afiliacje autorów:
Postek E. | - | IPPT PAN | Dubois F. | - | Université de Montpellier (FR) | Mozul R. | - | Université de Montpellier (FR) | Canadas P. | - | Université de Montpellier (FR) |
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33. |
Postek E., Sadowski T.♦, A Crack Model Around Junctions in WC/Co Composite,
SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), pp.1, 2016Słowa kluczowe: Metal-Ceramic Composite, Interface Elements, Crack Propagation at Composite Junctions Afiliacje autorów:
Postek E. | - | IPPT PAN | Sadowski T. | - | Lublin University of Technology (PL) |
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34. |
Postek E., Parameter sensitivity of a single layer tensegrity modelled tissue,
Mecánica Computacional, ISSN: 2591-3522, Vol.XXXIII, No.43, pp.2797, 2014 | |
35. |
Postek E., Caliendo C.♦, Latino P.M.♦, Numerical model of ALN-based bulk acoustic high-frequency resonators,
SolMech 2012, 38th Solid Mechanics Conference, 2012-08-27/08-31, Warszawa (PL), pp.316-317, 2012 | |
36. |
Postek E., Dubois F.♦, Mozul R.♦, Modeling of a collection of tensegrity particles with a nonsmooth discrete element method,
SolMech 2012, 38th Solid Mechanics Conference, 2012-08-27/08-31, Warszawa (PL), pp.28-29, 2012 | |
37. |
Postek E., A survey of tensegrity models of cells with design sensitivity analysis,
III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.44-45, 2012 | |
38. |
Postek E., Concept of an Agent-stress Model of a Tissue,
2nd International Conference on Material Modelling, 2012-08-31/09-02, Paryż (FR), pp.297, 2011 | |
39. |
Postek E., Parallel version of a design sensitivity tensegrity code,
TAM 2009, Transnational Access Meeting, HPC-Europa2 2009, 2009-10-14/10-16, Montpellier (FR), pp.1, 2009Streszczenie: The cytoskeleton is a tensegrity structure, The mechanics is important to the cells: „change the mechanical stresses on cancer cells and they can start to behave like healthy ones” [1]. The displacements and stresses change in the biological materials due to the growth, division and death of the cells. The cells receive signals for the actions. This constitutes the agent-stress based models of the tissue. [1] C. Ainsworth. Stretvhing the examination, Nature, 456, Dec., 696-699, 2008. Słowa kluczowe: cell mechanics, signals, design sensitivity Afiliacje autorów:
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40. |
Postek E., Smallwood R.♦, Hose R.♦, Finite deformation based model of cytoskeleton,
ICCB2009, IV International Congress on Computational Bioengineering including the first European Symposium on Biomedical Integrative Research, 2009-09-16/09-18, Bertinoro (IT), DOI: 10.6092/unibo/amsacta/2646, pp.53-53, 2009Streszczenie: The cytoskeleto is modelled as a tensegrity structure. It consists of tendons and struts [Stamenovic, 2005]. The basic tensegrity structures are developed from icosahedron.
The cells undergo finite deformations behaviour and their response to loading conditions is visco-elastic,
These types of structures are sensitive to initial prestressing what it intuitively natural since without the initial stress state they would not exist, The other factors affecting the mechanical behaviour of the cell are constitutive parameters and positions of the nodes, in fact, the shape of the cell. Słowa kluczowe: cytoskeleton, visco-elasticity, finite strains, prestressing Afiliacje autorów:
Postek E. | - | IPPT PAN | Smallwood R. | - | inna afiliacja | Hose R. | - | inna afiliacja |
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41. |
Postek E., Houseman G.A.♦, Jimack P.K.♦, Aspects of Non-Newtonian Viscoelastic Deformation Produced by Slip on a Major Strike- slip Fault,
AGU FALL MEETING 2008, American Geophysical Union Fall Meeting 2008, 2008-12-15/12-19, San Francisco (US), pp.1, 2008Streszczenie: Non-Newtonian flow occurs in crustal deformation processes on the long
timescales associated with large- scale continental deformation, and also
on the short time-scales associated with post-seismic deformation. The
co-seismic displacement is determined by the instantaneous elastic
response of the rocks on either side of the fault surface to the
distribution of slip on the surface of the fault. The post-seismic
deformation is determined by some combination of visco-elastic relaxation
of the medium and post-seismic creep on the fault. The response of the
crust may depend on elastic moduli, Poisson's ratio, temperature, pressure
and creep function parameters including stress exponent, activation
energy, activation volume and viscosity coefficient. We use the von Mises
function in describing the non-linear Maxwell visco-elastic creep models.
In this study we examine a model of a strike-slip fault crossing a 3D
block. The fault slips at time zero, and we solve for the viscoelastic
deformation field throughout the 3D volume using a 3D finite element
method. We perform parametric studies on the constitutive equation by
varying these parameters and the depth of the fault event. Our findings
are focused on the fact that the system is very sensitive to the above
mentioned parameters. In particular, the most important seems to be the
temperature profiles and stress exponent. The activation energy and the
pressure are of lower importance, however, they have their meaning. We
investigated the relaxation times and the deformation patterns. We took
the material properties as typical to dry quartzite and diabase. Depending
on the parameters the surface can be deformed permanently or the
deformation can decrease. We attempt to compare qualitatively the
calculated post-seismic response in terms of the post-seismic displacement
history of the earth's surface with InSAR patterns determined from recent
major strike-slip earthquakes. Quantitative comparison of the observations
with these numerical model results can in principle provide a better
understanding of the physical properties of the sub-surface and further
insight into the diagnostic properties of the earthquake cycles of major
fault systems.
Cite as: Author(s) (2008), Title, Eos Trans. AGU, 89(53), Fall Meet.
Suppl., Abstract T44B-07 Słowa kluczowe: rheology, crust, litosphere Afiliacje autorów:
Postek E. | - | IPPT PAN | Houseman G.A. | - | University of Leeds (GB) | Jimack P.K. | - | University of Leeds (GB) |
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42. |
Postek E.♦, Houseman G.A.♦, Jimack P.K.♦, Generic Models of Linear and Non-linear Visco-elastic Surface Deformation above a Fault,
EGU 2008, European Geosciences Union General Assembly 2008, 2008-04-13/04-18, Vienna (AT), pp.1, 2008Streszczenie: The ground displacements measured in the vicinity of a large strike-slip earthquake are
potentially important in diagnosing the state of stress on the fault and in the medium
surrounding. The co-seismic displacement is determined by the immediate elastic response
of the medium and the slip function on the fault-surface. The post-seismic
displacement is determined by a combination of post-seismic creep on the fault, viscoelastic
relaxation in the surrounding medium, and possibly poro-elastic deformation.
There are strong indications from previous earthquake studies that the visco-elastic
relaxation involves non-linear mechanisms, which produce faster deformation in the
early stages and slower deformation in the later stages than would occur with a linear
creep mechanism. In this study we examine a simplified model of a strike-slip fault
cutting a 3D block, and compute the surface displacement versus time functions for a range of different constitutive relations. We examine linear and non-linear Maxwell
visco-elasticity, and compare with the generalized linear Maxwell visco-elasticity. The
effect of non-linearities in the elasticity (finite strain theory) is also considered.We use
the von Mises flow function in describing the non-linear Maxwell visco-elastic creep
models in which viscous creep strain-rate is proportional to the nth power of the deviatoric
stress (formulated using the 2nd invariant of the stress tensor). We describe
analytical solutions used to validate the 3D code, and then consider the effect of the
exponent n on the time histories of the surface displacement fields above the fault.
We aim here to compare these numerical models with observations from actual fault
systems obtained using InSAR and GPS data. Among the factors affecting the surface deformation patterns are near-surface layering, and lateral variation of material
properties, as well as irregularities on the fault surface. In principle, the comparison
of observations with theory should provide a better understanding of the physical response
of the sub-surface, together with a better understanding of the earthquake cycle
as it operates on specific fault systems. Słowa kluczowe: surface deformation, seismic cycle, visco-elasticity, numerical models Afiliacje autorów:
Postek E. | - | inna afiliacja | Houseman G.A. | - | University of Leeds (GB) | Jimack P.K. | - | University of Leeds (GB) |
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43. |
Postek E.♦, Houseman G.A.♦, Jimack P.K.♦, Surface deformation during earthquake cycle for a layered visco-elastic crust,
Ada Lovelace Workshops on Modelling Mantle and Lithosphere Dynamics 10th International Workshop on Modeling of Mantle Convection and Lithospheric Dynamics, 2007-09-02/09-07, Carry-le-Rouet (FR), pp.1, 2007Słowa kluczowe: surface deformation, viso-elasticity, seismic cycle Afiliacje autorów:
Postek E. | - | inna afiliacja | Houseman G.A. | - | University of Leeds (GB) | Jimack P.K. | - | University of Leeds (GB) |
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44. |
Postek E.♦, Houseman G.A.♦, Jimack P.K.♦, Nonlinear effects during post-seismic visco-elastic deformation,
IUGG XXIV 2007, International Union of Geodesy and Geophysics General Assembly Earth, Our Changing Planet, 2007-07-02/07-13, Perugia (IT), No.JGS003, pp.207, 2007Słowa kluczowe: deformation, viscosity, power law Afiliacje autorów:
Postek E. | - | inna afiliacja | Houseman G.A. | - | University of Leeds (GB) | Jimack P.K. | - | University of Leeds (GB) |
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45. |
Postek E.♦, Houseman G.A.♦, Jimack P.K.♦, The effect of geometrical nonlinearity in visco-elastic deformation,
EGU 2007, European Geosciences Union, General Assembly 2007, 2007-04-15/04-20, Vienna (AT), No.9, pp.03087, 2007 | |
46. |
Dong L.L.♦, Lewis R.W.♦, Gethin D.T.♦, Postek E.W., Simulation of deformation of ductile pharmaceutical particles with finite element method,
ACME 2004, 12th Association of Computational Mechanics in Engineering Annnual Conference, 2004-04-05/04-06, Cardiff (GB), pp.1-5, 2004Streszczenie: In order to guarantee the strength and thus the quality of the tablets produced during the tabletting process, it is essential to understand the deforming characteristics of excipient binders. The present numerical work is motivated to provide an insight into the mechanical behaviour of the particle deformation of the excipient binder. In the present study pregelatinised starch is selected, which is known to behave in a ductile manner during compaction. An elasto-viscoplastic material model has been selected in the present study to simulate the deformation behaviour of the pregelatinised starch. Elasto-viscoplastic model 1S chosen because all the plastic deformation exhibits rate-dependency to some extent, and it is a well-developed model for simulating non-linear deformation which has been studied for four decades (Perzyna (1966), Zabaras and Arif (l992)). Słowa kluczowe: discrete element method, finite element method, viscoplasticity, adaptive meshing Afiliacje autorów:
Dong L.L. | - | inna afiliacja | Lewis R.W. | - | University of Wales (GB) | Gethin D.T. | - | University of Wales Swansea (GB) | Postek E.W. | - | IPPT PAN |
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47. |
Postek E.W., Lewis R.W.♦, Gethin D.T.♦, Ransing R.S.♦, Finite element model of mould filling during squeeze forming processes,
ACME 2004, 12th Association of Computational Mechanics in Engineering Annnual Conference, 2004-04-05/04-06, Cardiff (GB), pp.1-4, 2004Streszczenie: During mould filling due to decreasing of liquidus temperature takes place solidification pocess. The paper deals mostly with a presentation of an application of a microstructural solidification model. The Navier Stokes equation describing the flow problem is solved using Taylor Galerkin method. Słowa kluczowe: mould filling, microstructural solidification, thermomechanics Afiliacje autorów:
Postek E.W. | - | IPPT PAN | Lewis R.W. | - | University of Wales Swansea (GB) | Gethin D.T. | - | University of Wales Swansea (GB) | Ransing R.S. | - | inna afiliacja |
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48. |
Ahmad R.♦, Gethin D.T.♦, Lewis R.W.♦, Postek E., Design sensitivity of a sequentially coupled problem: casting,
ACME 2004, 12th Association of Computational Mechanics in Engineering Annnual Conference, 2004-04-05/04-06, Cardiff (GB), pp.1-4, 2004Streszczenie: The presented paper deals with the design sensitivity of a sequentially coupled thermo-mechanical problem. The key finding is to provide a tool for optimisation software (analytical design sensitivity gradients) for a sequentially coupled thermal-mechanical problem. Słowa kluczowe: casting process, thermomechanics, parameter sensitivity analysis Afiliacje autorów:
Ahmad R. | - | inna afiliacja | Gethin D.T. | - | University of Wales Swansea (GB) | Lewis R.W. | - | University of Wales Swansea (GB) | Postek E. | - | IPPT PAN |
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49. |
Karczewski J.A.♦, Postek E., Wierzbicki S.♦, Experimental shakedown analysis of double butt, prestressed, bolted connections,
6th International Conference, Modern Building Materials Structures and Techniques, 1999-05-19/05-22, Wilno (LT), pp.196-201, 1999Streszczenie: This paper deals with the experiment on double butt prestressed bolted connections. The goal of the experiment is to verify a 3D computational model of the connection. The connections are loaded cyclically according to a load program based on load variability observed in engineering practice
Słowa kluczowe: prestressing, deformability, ultimate load, elastooptic layer Afiliacje autorów:
Karczewski J.A. | - | Politechnika Warszawska (PL) | Postek E. | - | IPPT PAN | Wierzbicki S. | - | Politechnika Warszawska (PL) |
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50. |
Postek E., Kleiber M., Design sensitivity of reinforced concrete plate/shell structures,
CMM1995, XII Polish Conference on Computer Methods in Mechanics, 1995-05-09/05-13, Warszawa Zegrze (PL), pp.279-280, 1995Słowa kluczowe: parameter sensitivity, plate-shell structures, nonlinear analysis Afiliacje autorów:
Postek E. | - | IPPT PAN | Kleiber M. | - | IPPT PAN |
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51. |
Postek E., Hanganu A.♦, Onate E.♦, Barbat A.H.♦, Failure analysis of nuclear containment shells,
SOLMECH 30, 30th Polish Solid Mechanics Conference, 1994-09-19/09-23, Zakopane (PL), pp.199-199, 1994Streszczenie: The nuclear containment vessels or safety buildings are meant to protect the environment in case of a malfunction of the reactor. These structures are considered as of high responsibility and risk.Static analysis of a nuclear containment vessel treated as an symmetric shell is presented. The structure is subjected to the following loads: external pressure caused by prestressing and a monotonic increase in internal pressure until failure of the structure occurs. The behaviour of the structure is: highly nonlinear in the postcracking range. To reflect the material behaviour, two different constitutive models are used. The postcracking behaviour of concrete is described by means of an orthotropic damage model. Elasto-plastic behaviour with isotropic hardening is assumed for the steel. The structure is discretised by axisymmetric shell composite layered finite Elements based on the Reissner - Mindlin theory. Orthotropy in the meridional and circumferencial directions is introduced. This possibility is reserved only for steel reinforcement equivalent layers. The internal steel layer is modelled as an isotropic layer of steel with no slip between itself and concrete. To solve the finite element equilibrium equation the initial stiffness method is used. To follow the postfailure path of equilibrium the displacement control method is applied. The proposed methodology allows us to follow the behaviour of the structure up to a constant value of the internal pressure, while simultaneously increasing displacement are obtained . This phenomenon is considered as a complete failure of the structure. The point corresponds to the highest level of finite element damage indices and the overall damage index which is evaluated for the entire structure. In conclusion it is stated that the applied methodology provides a good approximation of the failure load, and the global behaviour of the structure is also well reflected at relatively low cost. Słowa kluczowe: nuclear containment vessel, prestressed reinforced structure, internal pressure growth, damage models, safety Afiliacje autorów:
Postek E. | - | IPPT PAN | Hanganu A. | - | Universidad Politécnica de Cataluña (ES) | Onate E. | - | Universidad Politécnica de Cataluña (ES) | Barbat A.H. | - | Universidad Politécnica de Cataluña (ES) |
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