scholarly journals A numerical finite fracture mechanics approach on asymmetric cracks in open-hole plates

2016 ◽  
Vol 2 ◽  
pp. 1991-1998 ◽  
Author(s):  
P.L. Rosendahl ◽  
P. Weißgraeber ◽  
N. Stein ◽  
W. Becker
Keyword(s):  
Fracture Mechanics ◽  
Finite Fracture Mechanics ◽  
Open Hole

A Finite Fracture Mechanics Model for the Prediction of the Notched Response and Large Damage Capability of Composite Laminates

2014 ◽  
Vol 627 ◽  
pp. 13-16 ◽  
Author(s):  
A. Arteiro ◽  
Giuseppe Catalanotti ◽  
J. Xavier ◽  
P.P. Camanho
Keyword(s):  
Fracture Mechanics ◽  
Composite Laminates ◽  
Present Model ◽  
Dimensionless Parameter ◽  
Notch Sensitivity ◽  
Sensitivity Factor ◽  
Mechanics Model ◽  
Finite Fracture Mechanics ◽  
Open Hole ◽  
Notched Strength

A new model based on Finite Fracture Mechanics (FFMs) has been proposed to predict the open-hole tensile strength of composite laminates [1]. Failure is predicted when bothstress-based and energy-based criteria are satisfied. This model is based on an analytical solution, and no empirical adjusting parameters are required, but only two material properties: the unnotched strength and the fracture toughness. In the present work, an extension of the proposed FFMs model to predict the notched response of composite laminates with notch geometries other than a circular opening [2] is presented and applied to the prediction of size effects on the tensile and compressive notched strength of composite laminates. The present model is also used to assess the notch sensitivity and brittleness of composite laminates by means of versatile design charts and by the identification of a dimensionless parameter designated as notch sensitivity factor. A further extension of the FFMs model is proposed, which takes into account the crack resistance curve of the laminate in the model's formulation, and it is used to predict the large damage capability of a non-crimp fabric thin-ply laminate [3].

scholarly journals Non-local criteria for the borehole problem: Gradient Elasticity versus Finite Fracture Mechanics

Meccanica ◽  
2021 ◽  
Author(s):  
A. Sapora ◽  
G. Efremidis ◽  
P. Cornetti
Keyword(s):  
Stress Concentration ◽  
Fracture Mechanics ◽  
Elastic Material ◽  
Fracture Criterion ◽  
Biaxial Loading ◽  
Gradient Elasticity ◽  
Energy Conditions ◽  
Material Behaviour ◽  
Finite Fracture Mechanics ◽  
Non Local

AbstractTwo nonlocal approaches are applied to the borehole geometry, herein simply modelled as a circular hole in an infinite elastic medium, subjected to remote biaxial loading and/or internal pressure. The former approach lies within the framework of Gradient Elasticity (GE). Its characteristic is nonlocal in the elastic material behaviour and local in the failure criterion, hence simply related to the stress concentration factor. The latter approach is the Finite Fracture Mechanics (FFM), a well-consolidated model within the framework of brittle fracture. Its characteristic is local in the elastic material behaviour and non-local in the fracture criterion, since crack onset occurs when two (stress and energy) conditions in front of the stress concentration point are simultaneously met. Although the two approaches have a completely different origin, they present some similarities, both involving a characteristic length. Notably, they lead to almost identical critical load predictions as far as the two internal lengths are properly related. A comparison with experimental data available in the literature is also provided.

scholarly journals Finite Fracture Mechanics Assessment in Moderate and Large Scale Yielding Regimes

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 602 ◽  
Author(s):  
Ali Reza Torabi ◽  
Filippo Berto ◽  
Alberto Sapora
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Large Scale ◽  
Ductile Failure ◽  
Equivalent Material ◽  
Failure Initiation ◽  
Equivalent Material Concept ◽  
Finite Fracture Mechanics ◽  
Al 7075 ◽  
Scale Yielding

The coupled Finite Fracture Mechanics (FFM) criteria are applied to investigate the ductile failure initiation at blunt U-notched and V-notched plates under mode I loading conditions. The FFM approaches are based on the simultaneous fulfillment of the energy balance and a stress requirement, and they involve two material properties, namely the fracture toughness and the tensile strength. Whereas the former property is obtained directly from experiments, the latter is estimated through the Equivalent Material Concept (EMC). FFM results are presented in terms of the apparent generalized fracture toughness and compared with experimental data already published in the literature related to two different aluminium alloys, Al 7075-T6 and Al 6061-T6, respectively. It is shown that FFM predictions can be accurate even under moderate or large scale yielding regimes.

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