scholarly journals Mixed-Mode Strain-Energy-Release Rate Effects on Edge Delamination of Composites

2008 ◽  
pp. 125-125-18 ◽  
Author(s):  
TK O'Brien
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Rate Effects ◽  
Edge Delamination

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 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.

Analysis of Mixed Mode II/III Crack in Bilayered Composite Beam

2012 ◽  
Vol 42 (4) ◽  
pp. 41-52 ◽  
Author(s):  
Angel S. Mladensky ◽  
Victor I. Rizov
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Composite Beam ◽  
Mixed Mode ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Mode Ii ◽  
Applied Forces

Abstract Mixed mode II/III crack investigation in cantilever bilayered unidirectional fiber reinforced composite beam is reported. The crack is situated between the layers. The two crack arms have different widths. Formula for the strain energy release rate is obtained by the linear elastic fracture mechanics methods using the magnitude of the applied forces, geometrical characteristics of the cross-section, and the elastic moduli of the layers. An equivalent shear modulus of the un-cracked beam portion is used. Several diagrams illustrating the results of parametrical analysis of the strain energy release rate are presented. The paper is a part of a research in the field of fracture behaviour of composite beams.

Analysis of mixed-mode II/III fracture in sandwich beams

2015 ◽  
Vol 11 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Victor Rizov
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Mode Ii ◽  
Foam Core ◽  
Content Type

Purpose – The purpose of this paper is to study theoretically the ability of the prestressed foam core composite sandwich Split Cantilever Beam (SCB) for generating mixed-mode II/III crack loading conditions (the mode II fracture was provided by prestressing the beam using imposed transverse displacements). Design/methodology/approach – The concepts of linear-elastic fracture mechanics were used. The fracture behavior was studied in terms of the strain energy release rate. For this purpose, a three-dimensional finite element model of the prestressed sandwich SCB was developed. The virtual crack closure technique was applied in order to analyze the strain energy release rate mode components distribution along the crack front. Findings – It was found that the distribution is non-symmetric. The analysis revealed that a wide mixed-mode II/III ratios range can be generated by varying the magnitude of the imposed transverse displacement. The influence of the sandwich core material on the mixed-mode II/III fracture behavior was investigated. For this purpose, three sandwich beam configurations with different rigid cellular foam core were simulated. It was found that the strain energy release rate decreases when the foam core density increases. Originality/value – For the first time, a mixed-mode II/III fracture study of foam core composite sandwich beam is performed.

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