FEM modelling of ceramic microstructures

• Autorzy: Niezgoda T. , Szymczyk W. , Małachowski J.

Warianty tytułu

PL

Modelowanie MES mikrostrusktur ceramicznych

• Języki publikacji: EN

Abstrakty

EN

The computer simulation of physical processes is one of the current direction of research development of body structures behaviour. The method, which was worked out (experimentally confirmed), gives an opportunity to analyse the same problems numerically, without expensive experiment. Recently the finite element method (FEM) has been used to invastigate the above problems. The authors of in the first part of the paper consider crack-face bridging, the stress field and the stress intensity factor ahead of the crack tip in the single-edge notched bend ceramics specimen using FEM. To solve this non-linear problem the incremental procedure was used. The results of this analysis are the stress and displacements on the bridging crack and external load, which allow to compute the stress intensity factor and fracture energy. The main aim of the second part of the work is to establish the method of numerical simulation of stress induced transformation of ZrO₂ from the tetragonal to monoclinic phase which takes place at the crack tip in two-phase Al₂O₃ - ZrO₂ ceramic composite. It is the base for the future crack growth numerical simulations in composite with the use of FEM models with the real grain size distribution and shape. The preliminary analysis allows us to estimate influence of phase transformation of the composite on the cracking resistance.

PL

Komputerowa symulacja procesów fizycznych jest jednym z obecnych kierunków badań zachowań ciała stałego. Metoda, która została wypracowana (sprawdzona eksperymentalnie), daje możliwość numerycznego analizowania tych problemów, bez ponoszenia kosztów na eksperymenty. W ostatnim czasie użyto metody elementów skończonych (MES) do badania tych zagadnień. Autorzy w pierwszej części pracy, przy pomocy MES, rozważają efekt mostkowania pęknięcia, pole naprężeń i współczynnik intensywności naprężeń na czole pęknięcia w zginanej, naciętej próbce ceramiki. W celu rozwiązania tego nieliniowego problemu zastosowano procedurę przyrostową. Wynikiem analizy są naprężenia i przemieszczenia w obszarze mostkowanego pęknięcia oraz obciążenie zewnętrzne, co pozwala wyliczyć współczynnik intensywności naprężeń i pracę pękania. Głównym celem drugiej części pracy jest opracowanie metody numerycznej symulacji indukowanej naprężeniowo przemiany ZrO₂ z fazy tetragonalnej w jednoskośną, która ma miejsce na czole pęknięcia w dwufazowych kompozytach ceramicznych Al₂O₃ - ZrO₂. Jest to podstawa do dalszych symulacji numerycznych kompozytów, przy użyciu modeli MES z rzeczywistym rozkładem wielkości i kształtem ziaren. Wstępna analiza pozwala oszacować wpływ przemiany fazowej w kompozycie na odporność na pękanie.

Słowa kluczowe

PL

MES; metoda elementów skończonych; analiza numeryczna; materiały ceramiczne

• Wydawca: Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Biuletyn Wojskowej Akademii Technicznej
• Rocznik: 2003
• Tom: Vol. 52, nr 8-9
• Strony: 225--246
• Opis fizyczny: Bibliogr. 42 poz.

Twórcy

autor

Niezgoda T.

• Department of General Mechanics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland

autor

Szymczyk W.

• Department of General Mechanics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland

autor

Małachowski J.

• Department of General Mechanics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland

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