Functionally Graded Plate Fracture Analysis Using the Field Boundary Element Method

This paper describes the Field Boundary Element Method (FBEM) applied to the fracture analysis of a 2D rectangular plate made of Functionally Graded Material (FGM) to calculate Mode I Stress Intensity Factor (SIF). The case study of this Field Boundary Element Method is the transversely isotropic plane plate. Its material presents an exponential variation of the elasticity tensor depending on a scalar function of position, i.e., the elastic tensor results from multiplying a scalar function by a constant taken as a reference. Several examples using a parametric representation of the structural response show the suitability of the method that constitutes a Stress Intensity Factor evaluation of Functionally Graded Materials plane plates even in the case of more complex geometries.

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Functionally Graded Plate Fracture by Field Boundary Element

10.20944/preprints202107.0487.v1 ◽

2021 ◽

Author(s):

Simone Palladino ◽

Luca Esposito ◽

Paolo Ferla ◽

Renato Zona ◽

Vincenzo Minutolo

Keyword(s):

Stress Intensity Factor ◽

Stress Intensity ◽

Boundary Element Method ◽

Intensity Factor ◽

Boundary Element ◽

Scalar Function ◽

Functionally Graded ◽

Field Boundary ◽

Plane Plate ◽

Element Method

The paper describes the Field Boundary Element Method applied to the fracture analysis of a 2D rectangular plate made of Functionally Graded Material to calculate Mode I Stress Intensity Factor. The object of the Field Boundary Element Method is the transversely isotropic plane plate. Its material presents an exponential variation of the elasticity tensor depending on a scalar function of position, i.e., the elastic tensor results from multiplying a scalar function by a constant taken as a reference. Several examples using a parametric representation of the structural response show the suitability of the method that constitutes a sight of Stress Intensity Factor evaluation of Functionally Graded Materials plane plates even in the case of more complex geometries.

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Research on Fracture Behavior of a Cracked Film-Substrate Medium

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.324-325.903 ◽

2006 ◽

Vol 324-325 ◽

pp. 903-906

Author(s):

Bao Liang Liu ◽

Xian Shun Bi

Keyword(s):

Stress Intensity Factor ◽

Stress Intensity ◽

Boundary Element Method ◽

Intensity Factor ◽

Boundary Element ◽

Fracture Behavior ◽

Thickness Ratio ◽

Film Substrate ◽

Substrate Medium ◽

Element Method

This study gives the problem of a crack in the film oriented perpendicular to the film-substrate interface with the crack tip terminating at the interface. Based on Beuth’s theory, three-dimensional model is simplified to plane strain problems, which obtains fracture mechanisms of a cracked film-substrate medium by applying the boundary element method(BEM). The method aptly resolves the problem involving stress concentration and, further, that this study develops the multi-region boundary element method and applies it to evaluate the cracked film-substrate medium. It shows that the stress intensity factor is affected by the different elastic mismatches and the thickness ratio of the film and the substrate. These results indicate: 1) The stress intensity factor has remarkable increased with the decrease of the thickness ratio of the film and the substrate. The effect of the fracture behavior of film is negligible when the thickness ratio of the film and the substrate is above 10, therefore, it is treated as thin film; 2) The stress intensity factor will decrease with the increase of α ( −1 pα p +1) for β = 0 and β =α / 4 , where α and β are called Dundurs parameters. What’s more, this paper studies the special condition of the film-substrate medium, which is the analysis of the fracture of the absence of any elastic mismatch between the film and the substrate, i.e.α=β=0, and revision of the formula of Xia and Hutchinson is put forward for the stress intensity factor of the deep crack problems by comparing to the former conclusions of Y.Murakami.

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