Strain energy release rate in combination with reinforcement isotropic solid model (SERIS): A new mixed-mode I/II criterion to investigate fracture behavior of orthotropic materials

2021 ◽  
Vol 113 ◽  
pp. 102962
Author(s):  
Zahra Khaji ◽  
Mahdi Fakoor
Keyword(s):  
Release Rate ◽  
Mixed Mode ◽  
Strain Energy ◽  
Fracture Behavior ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Orthotropic Materials ◽  
Solid Model ◽  
Mode I ◽  
Isotropic Solid

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.

scholarly journals Measuring the Cohesive Law in Mode I Loading of Eucalyptus globulus

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 23 ◽  
Author(s):  
Almudena Majano-Majano ◽  
Antonio Lara-Bocanegra ◽  
José Xavier ◽  
José Morais
Keyword(s):  
Energy Release ◽  
Release Rate ◽  
Eucalyptus Globulus ◽  
Strain Energy ◽  
Fracture Behavior ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Mode I ◽  
Cohesive Law ◽  
Cohesive Laws

Assessing wood fracture behavior is essential in the design of structural timber elements and connections. This is particularly the case for connections with the possibility of brittle splitting failure. The numerical cohesive zone models that are used to simulate the fracture behavior of wood make it necessary to assume a cohesive law of the material that relates cohesive tractions and crack opening displacements ahead of the crack tip. This work addresses the determination of the fracture cohesive laws of Eucalyptus globulus, a hardwood species with great potential in timber engineering. This study centres on Mode I fracture loading for RL and TL crack propagation systems using Double Cantilever Beam tests. The Compliance-Based Beam Method is applied as the data reduction scheme in order to obtain the strain energy release rate from the load-displacement curves. The cohesive laws are determined by differentiating the relationship between strain energy release rate and crack tip opening displacement. The latter is measured by the digital image correlation technique. High strain energy release rates were obtained for this species, with no big differences between crack propagation systems. The difference between the crack systems is somewhat more pronounced in terms of maximum stress that determines the respective cohesive laws.

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.

scholarly journals Fracture Behavior of Carbon-Epoxy under Different Loading

2020 ◽  
Vol 9 (3) ◽  
pp. 1145-1149
Keyword(s):  
Fracture Surface ◽  
Strain Energy ◽  
Fracture Behavior ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Mode I ◽  
Mode Ii ◽  
New Materials ◽  
The Common ◽  
Mode Ii Loading

Delamination is the common failures of composite material attributed to various reasons, most importantly the potential stiffness degradation leading to small flaws and subsequently theypropagate, and it becomes essential to characterize the new materials for interlaminar fracture. For the present study Carbon /epoxy system of IM7/8552 was investigated under mode I and mode II loading. Material was formed into unidirectional laminates with Teflon inserts at its mid length. The specimens were machined according to ASTM standards, Tests were executed on a quasi-static Intron 8225, with load control at 5 mm/ min and 2 m/min for the mode -I and mode-II respectively. The strain energy release rate was found to be GIC=0.266 kJ/m2 and GIIC=0.687 kJ/m2 . Fiberbridging was prominently absent in the DCB samples Examination of the fracture surface by SEM at SAIF, in IIT{M) and the nature of the fracture surface revealed the typical failure mechanism pertaining to mode-I and mode-II failuremechanisms

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