scholarly journals Moving interfacial Griffith crack between bonded dissimilar media

2005 ◽  
Vol 2005 (3) ◽  
pp. 289-299 ◽  
Author(s):  
S. Mukherjee ◽  
S. Das
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Crack Opening Displacement ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Crack Opening ◽  
Strain Energy Release ◽  
Griffith Crack ◽  
Opening Displacement

The plane strain problem of determining strain energy release rate, crack energy, and crack-opening displacement (COD) for a moving Griffith crack at the interface of two dissimilar orthotropic half-planes is considered. The problem is reduced to a pair of singular integral equations of second kind which have finally been solved by using Jacobi polynomials. Graphical plots of the strain energy release rate, crack energy, and crack-opening displacement for the problem in different particular cases are presented.

A Study of Crack Growth in Sandwich Composite Beams

2001 ◽  
Author(s):  
Sami I. El-Sayed ◽  
Srinivasan Sridharan
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Crack Opening ◽  
Strain Energy Release ◽  
Beam Specimen ◽  
Crack Kinking ◽  
Interfacial Delamination

Abstract The paper proposes models to track the face-core interfacial delamination growth and crack kinking into the sandwich core, respectively. The models consist in interposing a cohesive layer along a pre-existing delamination or an identified plane of crack propagation. The former, designated as CLD (cohesive layer delamination model) is investigated first in detail using an example of a restrained beam specimen. The Influence of the key parameters of the model, viz. the thickness of the cohesive layer and the strength and stiffness of the cohesive layer material, have been studied. It is found that the model is fairly robust and is not sensitive to changes in parameters other than the critical strain energy release rate. The second model is a highly simplified one, but it is nevertheless a comprehensive model which can track the crack path by identifying crack planes in various elements using a maximum tensile stress criterion. This is designated as CLDK model as it deal with delamination and crack kinking — whichever is the preferred mode of fracture. The models are constructed ensuring that the crack opening is controlled by the critical value of strain energy release rate in mode I fracture. Experimental results of two sandwich specimens, viz. bottom restrained beams with 0° and −10° tilt angle respectively were used for comparison. The results indicate that the both the models are able to capture the initiation and track the growth of the interfacial delamination. The CLDK model tracks the crack kinking into the core, and its subsequent return to the facesheet-core interface.

On the Axial Rigidity of a Perforated Strip and the Strain Energy Release Rate in a Centrally Notched Strip Subjected to Uniaxial Tension

1964 ◽  
Vol 86 (4) ◽  
pp. 693-697 ◽  
Author(s):  
R. G. Forman ◽  
A. S. Kobayashi
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Uniaxial Tension ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Theoretical Studies ◽  
Correction Factors ◽  
Elasticity Solutions

This paper presents theoretical studies on the axial rigidities in strips with circular and elliptical perforations and subjected to uniaxial tension. Greenspan’s original derivations on these axial rigidities [2] were improved by using the elasticity solutions by Howland [6] and Ishida [7] for infinite strips with circular and elliptical perforations, respectively. Finally, the correction factors for centrally notched strips subjected to uniaxial tension were rederived from the above results following the energy approach by Irwin and Kies [3].

Nonlinear Approach for Strain Energy Release Rate in Micro Cantilevers

2010 ◽  
Author(s):  
Arash Kheyraddini Mousavi ◽  
Seyedhamidreza Alaie ◽  
Maheshwar R. Kashamolla ◽  
Zayd Chad Leseman
Keyword(s):  
Surface Roughness ◽  
Crack Propagation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Rigid Substrate ◽  
Micro Cantilever

An analytical Mixed Mode I & II crack propagation model is used to analyze the experimental results of stiction failed micro cantilevers on a rigid substrate and to determine the critical strain energy release rate (adhesion energy). Using nonlinear beam deflection theory, the shape of the beam being peeled off of a rigid substrate can be accurately modeled. Results show that the model can fit the experimental data with an average root mean square error of less than 5 ran even at relatively large deflections which happens in some MEMS applications. The effects of surface roughness and/or debris are also explored and contrasted with perfectly (atomically) flat surfaces. Herein it is shown that unlike the macro-scale crack propagation tests, the surface roughness and debris trapped between the micro cantilever and the substrate can drastically effect the energy associated with creating unit new surface areas and also leads to some interesting phenomena. The polysilicon micro cantilever samples used, were fabricated by SUMMIT V™ technology in Sandia National Laboratories and were 1000 μm long, 30 μm wide and 2.6 μm thick.

Influence of Loading History on Delamination in Multilayered Beam with Creep

2021 ◽  
Vol 1046 ◽  
pp. 23-28
Author(s):  
Victor Iliev Rizov
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Time Dependent ◽  
External Loading ◽  
Loading History ◽  
Multilayered Beam

The present paper deals with an analytical study of the time-dependent delamination in a multilayered inhomogeneous cantilever beam with considering of the loading history. The multilayered beam exhibits creep behaviour that is treated by using a non-linear stress-strain-time relationship. The material properties are continuously distributed along the thickness and length of the layers. The external loading is applied in steps in order to describe the loading history. The analysis reveals that during each step of the loading, the strain energy release rate increases with time. The influences of crack length and location on the time-dependent strain energy release rate are also investigated.

Effect of Plastic Deformation on the Strain Energy Release Rate in a Centrally Notched Plate Subjected to Uniaxial Tension

1966 ◽  
Vol 88 (1) ◽  
pp. 82-86 ◽  
Author(s):  
R. G. Forman
Keyword(s):  
Plastic Deformation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Uniaxial Tension ◽  
Correction Factor ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Linear Elastic

This paper presents theoretical studies on the effect of plastic deformation on the strain energy release rate, G, of a plate under uniaxial tension with a central propagating crack. The linear elastic fracture mechanics solution for G is improved by using the Dugdale model for the crack and yielded region to obtain the axial rigidity of the plate. The axial rigidity is then used to obtain the solution for the strain energy release rate as the crack propagates. It is found that plastic deformation has a pronounced effect on G. A correction factor is presented for correcting the linear elastic solution for the strain energy release rate. The correction factor is found to depend upon the nominal (gross) stress to material yield stress ratio and the crack length to plate width ratio.

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