Stanovení součinitele intenzity napětí ve funkčně gradientních materiálech

An evaluation of the stress intensity factor in functionally graded materials

článek v časopise - ostatní, Jost

en

Functionally graded materials (FGM) are characterised by variations in their material properties in terms of their geometry. They are often used as a coating for interfacial zones to protect the basic material against thermally or mechanically induced stresses. FGM can be also produced by technological process for, example butt-welding of polymer pipes. This work is focused on a numerical estimation of the stress intensity factor for cracks propagat-ing through FGM structure. The main difficulty of the FE model creation is the accurate description of continual changes in mechanical properties. An analysis of the FGM layer bonded from both sides with different homoge-nous materials was performed to study the influence of material property distribution. The thickness effect of the FGM layer is also discussed. All analyses are simulated as a 2D problem of an edge crack specimen. In this pa-per, the above effects are quantified and conclusions concerning the applicability of the proposed model are dis-cussed.

Tato práce je zaměřena na numerický odhad součinitele intenzity napětí pro trhliny šířící se skrze funkčně gradientní strukturu. Hlavní obtížnost numerické simulace je dobrý popis gradientní změny mechanických vlastností. V práci je modelována gradientní vrstva mezi dvěma homogenními materiály a studován charakter změny mechanických vlastností z materiálu 1 do materiálu 2. Vliv tloušťky vrstvy je zde diskutován. Simulace jsou provedeny na 2D modelu pomocí metody konečných prvků.

Functionally graded materials (FGM) are characterised by variations in their material properties in terms of their geometry. They are often used as a coating for interfacial zones to protect the basic material against thermally or mechanically induced stresses. FGM can be also produced by technological process for, example butt-welding of polymer pipes. This work is focused on a numerical estimation of the stress intensity factor for cracks propagat-ing through FGM structure. The main difficulty of the FE model creation is the accurate description of continual changes in mechanical properties. An analysis of the FGM layer bonded from both sides with different homoge-nous materials was performed to study the influence of material property distribution. The thickness effect of the FGM layer is also discussed. All analyses are simulated as a 2D problem of an edge crack specimen. In this pa-per, the above effects are quantified and conclusions concerning the applicability of the proposed model are dis-cussed.

funkčně gradientní materiál; lineárně elastická lomová mechanika; diskretizašní postup; mocninná změna materiálových vlastností

functionally graded material; linear elastic fracture mechanics; discretization methodology; power-law material change

2009

28.12.2009

University of West Bohemia

Plzeň

1802-680X

Applied and Computational Mechanics

3

2

401–410

10