Equivalent energy release rate and crack stability in the End Notched Flexure with inserted roller mixed mode I/II test

2017 ◽  
Vol 87 ◽  
pp. 99-109 ◽  
Author(s):  
A. Boyano ◽  
J. De Gracia ◽  
A. Arrese ◽  
F. Mujika
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Mode I ◽  
Crack Stability

scholarly journals Crack Growth and Energy Release Rate for an Angled Crack under Mixed Mode Loading

2020 ◽  
Vol 10 (12) ◽  
pp. 4227
Author(s):  
Yali Yang ◽  
Seok Jae Chu ◽  
Wei song Huang ◽  
Hao Chen
Keyword(s):  
Energy Release Rate ◽  
Numerical Method ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Crack Tip ◽  
Theoretical Expression ◽  
Propagation Mechanism ◽  
Mode I ◽  
Theoretical Derivation

The evaluation of energy release rate with angle is still a challenging task in metal crack propagation analysis, especially for the mixed Mode I-II-III loading situation. In this paper, the energy release rate associated with stress intensity factors at an arbitrary angle under mixed mode loadings has been investigated using both a numerical method and theoretical derivation. A relatively simple and precise numerical method was established through a series of spatial-inclined ellipses in Mode I-II and ellipsoids in Mode I-II-III, with different propagation angles computed from simulation. Meanwhile, a theoretical expression of the energy release rate with angle for a crack tip under a I-II-III mixed mode crack was deduced based on the propagation mechanism of the crack tip under the influence of a stress field. It is confirmed that the theoretical expression deduced could provide results as accurately as the present numerical method. The present results were confirmed to be effective and accurate by comparison with experimental data and other literature.

Numerical Examination of Mixed Mode Crack in SSY: A Review

2013 ◽  
Vol 275-277 ◽  
pp. 198-202
Author(s):  
Prasad S. Godse ◽  
Sangram A. Gawande ◽  
Sunil Bhat
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Small Scale ◽  
Mode I ◽  
Mode Ii ◽  
Fracture Parameter ◽  
Conservation Of Energy ◽  
Mixed Mode Crack

The paper reviews the numerical methodology to investigate fracture parameter namely energy release rate, G, of a mixed mode crack. An inclined, through, centre crack is assumed in a ductile steel plate subjected to bi-axial tension. Applied stress and crack size are suitably selected to simulate small scale yielding (SSY) condition at the crack tips. The cracked plate is modelled by finite element method. Both plane stress and plane strain situations are examined. G value is found from J integral. Equations of transformation are employed to obtain normal and shear stress in the plane of the crack. G is then again determined for Mode I and Mode II cracks by modelling each case separately. The analysis is finally validated by fulfilment of the conservation of energy release rate criterion, G (Mixed mode) = G (Mode I) + G (Mode II).

scholarly journals Analysis of Mixed Mode I/II/III Fracture in Foam Core Sandwich Structures Using Imposed Displacement Split Cantilever Beams

2015 ◽  
Vol 45 (3) ◽  
pp. 69-82
Author(s):  
V. Rizov
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Mode I ◽  
Foam Core

Abstract Static fracture in foam core sandwich structures under mixed mode I/II/III loading conditions was studied theoretically. In order to generate such loading conditions, a thread guide was used to impose in- plane displacements of the lower crack arm of a sandwich Split Cantilever Beam (SCB). The upper crack arm was loaded by a transverse force. A three-dimensional finite element model of the imposed displacement sandwich SCB configuration was developed. The fracture was studied applying the concepts of linear-elastic fracture mechanics. The strain energy release rate mode components distribution along the crack front was analyzed using the virtual crack closure technique. The influence of the imposed displacement magnitude and the crack length on the fracture was evaluated. The effect of the sandwich core material on the mixed-mode I/II/III fracture was studied. For this purpose, finite element simulations were carried-out assuming that the core is made by different rigid cellular foams. It was found that the strain energy release rate decreases when the foam density increases.

Mode I and Mixed Mode Energy Release Rate Values for Delamination of Graphite/Epoxy Test Specimens

1987 ◽  
Vol 21 (2) ◽  
pp. 105-123 ◽  
Author(s):  
Edmund F. Rybicki ◽  
Tony D. Hernandez ◽  
John E. Deibler ◽  
Ronald C. Knight ◽  
Steven S. Vinson
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Mode I ◽  
Mode Energy

scholarly journals Influence of the Test Method on the Characterization of the Fatigue Delamination Behavior of a Composite Material under Mixed Mode I/II Fracture

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1788 ◽  
Author(s):  
Antonio Argüelles ◽  
Clara Rocandio ◽  
Silvia Rubiera ◽  
Isabel Viña ◽  
Jaime Viña
Keyword(s):  
Composite Material ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Fatigue Loading ◽  
Test Methods ◽  
Test Method ◽  
Mode I

Composite materials manufactured by overlapping plies with certain specific geometries are likely to lose part of their strength due to the presence of internally delaminated regions. The aim of this paper is to experimentally evaluate the generation and propagation of these interlaminar cracks in a carbon-epoxy composite material subjected to fatigue loading under mixed mode I/II fracture. Two different test methods were used for this purpose: The standardized mixed-mode bending (MMB) test and the asymmetric double cantilever beam (ADCB) test, with the goal of exploring the viability of the ADCB test as a simpler alternative to perform than the MMB test, especially in fatigue testing. With this aim in mind and after prior static characterization of the material in which the critical values of the energy release rate were determined under both test methods, the levels of the energy release rate to be applied in fatigue tests were defined for two mode mixity ratios, GII/Gc = 0.2 and 0.4 (0.34 ADCB), and a fatigue loading ratio, R = Gmin/Gmax = 0.1. The G-N fatigue onset curves were subsequently obtained from these experimental data. The most relevant result of the study is that the fatigue limits obtained using the MMB method are generally more conservative than those obtained via the ADCB method.

The Edge Delamination Test: Measuring the Critical Adhesion Energy of Thin-Film Coatings, Part II: Mode Mixity & Application

1994 ◽  
Vol 338 ◽  
Author(s):  
Edward O. Shaffer ◽  
Scott A. Sikorski ◽  
Frederick J. McGarry
Keyword(s):  
Thin Film ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Mode I ◽  
Rigid Substrate ◽  
Edge Delamination

ABSTRACTThe edge delamination test (EDT) is being developed to measure the critical energy required to cause a thin film, under biaxial tensile stress, to debond from a rigid substrate[1]. The test uses circular features etched through biaxially stressed films adhered to a rigid substrate. If the stress is large enough, a stable debond ring grows radially about the feature. We use a finite element analysis to model the test, solving for the applied strain energy release rate as a function of crack length, feature hole radius and other geometrical parameters. The model identifies both mode I and mode II components of the strain energy release rate, and agrees with previous analytical solutions for the total debond energy. However, the model predicts, with a very refined mesh at the crack tip, the fracture process is pure mode I. To explore this result, critical strain energy release rates from the EDT and the island blister test (IBT) are compared. This agreement supports the model prediction that the failure process in the EDT is modeI peeling.

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