The stress intensity factor (SIF) distribution along the front of a through-the-thickness crack is significantly influenced by the presence of the 3D corner (vertex) singularities. All past 3D finite element studies indicated that for mode I, SIF rapidly decreases near the free surface and for mode II, it sharply increases. From the previous numerical simulations, it is unclear what the limiting values of SIF near the surface are and whether these values are infinite or bounded at the vertex point. In this paper, we conduct a careful finite element study and propose a theoretical equation, which describes the SIF behaviour near the vertex. We demonstrate that the asymptotic behaviour of SIF near the surface is governed by the difference in the strength of the corner and edge singularities. Furthermore, we validate our numerical approach and calculations by utilising the invariant properties of J-integral. © 2015 Wiley Publishing Ltd.

Effect of vertex singularities on stress intensities near plate free surfaces / He, Z.; Kotousov, A.; Berto, F.. - In: FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES. - ISSN 8756-758X. - 38:7(2015), pp. 860-869. [10.1111/ffe.12294]

### Effect of vertex singularities on stress intensities near plate free surfaces

#### Abstract

The stress intensity factor (SIF) distribution along the front of a through-the-thickness crack is significantly influenced by the presence of the 3D corner (vertex) singularities. All past 3D finite element studies indicated that for mode I, SIF rapidly decreases near the free surface and for mode II, it sharply increases. From the previous numerical simulations, it is unclear what the limiting values of SIF near the surface are and whether these values are infinite or bounded at the vertex point. In this paper, we conduct a careful finite element study and propose a theoretical equation, which describes the SIF behaviour near the vertex. We demonstrate that the asymptotic behaviour of SIF near the surface is governed by the difference in the strength of the corner and edge singularities. Furthermore, we validate our numerical approach and calculations by utilising the invariant properties of J-integral. © 2015 Wiley Publishing Ltd.
##### Scheda breve Scheda completa
2015
Crystallography; Finite element method; Stress intensity factors; Thermoelectricity, Asymptotic behaviour; Asymptotic solutions; Invariant properties; J integral; Numerical approaches; Straight crack; Stress intensity factor (SIF); vertex singularities, Crack tips; crack-tip asymptotic solution; FEA; J-integral; straight crack front; stress intensity factor; vertex singularities
01 Pubblicazione su rivista::01a Articolo in rivista
Effect of vertex singularities on stress intensities near plate free surfaces / He, Z.; Kotousov, A.; Berto, F.. - In: FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES. - ISSN 8756-758X. - 38:7(2015), pp. 860-869. [10.1111/ffe.12294]
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Utilizza questo identificativo per citare o creare un link a questo documento: `https://hdl.handle.net/11573/1688069`