Numerická analýza sub-kritického růstu trhlin v keramických kompozitních materiálech

Numerical Analysis of Sub-Critical Crack Growth in Particulate Ceramic Composites

článek v časopise ve Web of Science, Jimp

en

The strength of glass or ceramic containing materials can be affected by the environment (stress corrosion). Under applied stress, crack-like defects may grow (sub-critically) for stress intensity factors, KI, below the fracture toughness of the material, KIc. The aim of the present work was to develop a two-dimensional finite element model to analyze the subcritical crack growth behavior of ceramic-based particulate composites. The maximum tangential stress criterion (MTS) was used to predict the direction of the crack propagation, in the framework of linear elastic fracture mechanics. The modeled material was a Low Temperature Co-fired Ceramic (LTCC), containing alumina particles embedded in a glass matrix. The experimentally determined SCCG material behavior (i.e. v-KI data) was implemented in the numerical model. The effect of the elastic modulus of the particles on the subcritical crack propagation was investigated. The conclusions of this paper can contribute to a better understanding of the subcritical propagation of cracks in particulate composites.

Pevnost keramických kompozitních materiálů bývá často ovlivněna i prostředím, ve kterém se daná součást provozuje. V provozním zatížení se pak mohou trhliny šířit i při hodnotách nižších, než je lomová houževnatost. Cílem práce bylo navrhnout 2D výpočtový model a pomocí něj dále analyzovat šíření trhliny v kompozitu. K určení směru bylo použito MTS kritérium. Z experimentu byly převzaty hodnoty k určení zbytkové životnosti.

The strength of glass or ceramic containing materials can be affected by the environment (stress corrosion). Under applied stress, crack-like defects may grow (sub-critically) for stress intensity factors, KI, below the fracture toughness of the material, KIc. The aim of the present work was to develop a two-dimensional finite element model to analyze the subcritical crack growth behavior of ceramic-based particulate composites. The maximum tangential stress criterion (MTS) was used to predict the direction of the crack propagation, in the framework of linear elastic fracture mechanics. The modeled material was a Low Temperature Co-fired Ceramic (LTCC), containing alumina particles embedded in a glass matrix. The experimentally determined SCCG material behavior (i.e. v-KI data) was implemented in the numerical model. The effect of the elastic modulus of the particles on the subcritical crack propagation was investigated. The conclusions of this paper can contribute to a better understanding of the subcritical propagation of cracks in particulate composites.

lomová mechanika, šíření trhlin, metoda konečných prvků, odhad životnosti

Fracture Mechanics; Low Temperature Co-fired Ceramics; Micro-crack Propagation; Finite Element Method; Lifetime Estimation

2014

01.07.2014

ELSEVIER

2211-8128

3

1

2071–2076

6