The Energy Release Rate for Decohesion in Thin Multilayered Films on Substrates

1997 ◽  
Vol 473 ◽  
Author(s):  
Ming. Y. He ◽  
Guanghai Xu ◽  
David R. Clarke ◽  
Qing Ma ◽  
H. Fujimoto
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Line Width ◽  
Release Rate ◽  
Metal Layer ◽  
Strain Energy Release ◽  
Intrinsic Stress ◽  
The Finite Element Method ◽  
Energy Release Rates ◽  
Strain Energy Release Rates

ABSTRACTThe strain energy release rates for the converging decohesion crack in a multilayered film on a substrate have been calculated using the finite element method. The results for the energy release rate as a function of the intrinsic stress, the thickness of the superlayer and the modulus ratio will be presented. A simple functional form for the results will be shown. The effects of plasticity of the thin metal layer on the energy release rate have been examined. The results show that the effect of plastic deformation is not significant for the converging decohesion crack. The effects of the line width have also been addressed. The results show that for two-layer films the energy release rate for steady-state decohesion cracks decreases dramatically as B/h decreases, in the range B/h<40, where B is the line width and h is the thickness of the superlayer. For narrow lines the plane strain solutions overestimate the energy release rate. The numerical results are consistent with the experimental observations on lines with different width.

Strain-energy release rate for a single-edge-cracked circular bar in tension

1978 ◽  
Vol 13 (2) ◽  
pp. 83-89 ◽  
Author(s):  
O E K Daoud ◽  
D J Cartwright ◽  
M Carney
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Circular Cross Section ◽  
Strain Energy Release ◽  
Energy Release Rates ◽  
Circular Bar ◽  
Strain Energy Release Rates

The strain-energy release rate is determined for an edge crack in a uniformly stressed bar of circular cross-section. Values of the strain-energy release rate, obtained using a finite-element representation of the bar and by measuring the compliance of the bar experimentally, are shown to be in close agreement. For crack depths of less than one-half diameter, the strain-energy release rates are found to be lower than existing results on rectangular bars having the same relative crack length.

A new Interface Element Method on Computation of the Interface Crack Propagation Energy Release Rate

2012 ◽  
Vol 204-208 ◽  
pp. 4573-4577
Author(s):  
Zhi Peng Zhong ◽  
Shui Wan ◽  
Lin Yun Zhou
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Crack Tip ◽  
Strain Energy Release ◽  
Interface Element ◽  
Energy Release Rates ◽  
Internal Forces ◽  
Strain Energy Release Rates ◽  
Element Method

A new interface element method was proposed to calculate the strain energy release rates(SERR) based on the virtual crack closure technique (VCCT). A Lagrange multiplier was introduced between the node pair at crack tip to obtain the internal forces. Then from the VCCT, the SERR was solved by using the forces and displacements near the crack tip. Examples for stationary cracks under the two typical cases are given. Meanwhile, the relationship curves between crack energy release rate and the length of crack, plate depths were plotted respectively.The example shows that the interface element used to calculate the SERR is simple, efficient, and highly accurate in analysis of 2D crack growth problems, and without requiring the special singularity element or collapsed element at crack tip.

Strain energy release rates and the fatigue growth of matrix cracks in model arrays in composite laminates

1991 ◽  
Vol 432 (1886) ◽  
pp. 427-444 ◽  
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Crack Growth ◽  
Release Rate ◽  
Composite Laminates ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Matrix Cracks ◽  
Energy Release Rates

Crack growth in the transverse plies of cross-ply composite laminates has been investigated both experimentally and theoretically. Expressions for the strain energy release rate associated with the growth of cracks in model arrays have been obtained using both the compliance approach and the energy method. Measurements of compliance change with crack length were obtained using glass-epoxy laminates and compared with various predictions. Correlations between the crack growth rate and the strain energy release rate range indicate that a Paris law is applicable.

Application of Fracture Mechanics to Crack Growth in Rubber-Cord Laminates

2001 ◽  
Vol 74 (3) ◽  
pp. 509-524 ◽  
Author(s):  
G. J. Lake
Keyword(s):  
Fracture Mechanics ◽  
Energy Release Rate ◽  
Energy Release ◽  
Crack Growth ◽  
Release Rate ◽  
Strain Energy ◽  
Fatigue Cracks ◽  
Strain Energy Release ◽  
Energy Release Rates ◽  
Laminated Structures

Abstract The use of a fracture mechanics approach based on the strain energy release rate to assess failure due to the growth of fatigue cracks in rubber—cord laminated structures is discussed. The mechanics of crack propagation is considered for cracking either between the plies or around individual cords, and also for crack initiation and growth near cord ends. Energy release rates can be calculated approximately for each of these cases and enable the laminate results to be related to the independently measured crack growth characteristics of the rubber. Experimental energy release rate determinations, from compliance changes produced by propagating model inter-ply cracks by cutting, provide a check on the accuracy of the calculated energies. The approach identifies material properties relevant to laminate failure and indicates the effects of loading, design and construction parameters on the rate and nature of failure.

Strength Determination Based on the Results of Modeling the Crack Propagation in a Nanostructured Hard Alloy

2019 ◽  
Vol 806 ◽  
pp. 45-50
Author(s):  
Maksim Dvornik ◽  
Elena Mikhailenko
Keyword(s):  
Crack Propagation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Volume Fraction ◽  
Strain Energy Release ◽  
The Finite Element Method ◽  
Intermediate Layers ◽  
Cobalt Layer ◽  
Co Alloys

The process of crack propagation from the initial pore in the microstructures of WC-Co alloys with different volume fraction of the cobalt phase was studied by simulation of the stressed state by the finite element method. A calculation of the energy release rate during the propagation of crack through sections which consist of the carbide grains and the cobalt phase was made. It is shown that the strain energy release rate increases with crack propagation in WC grains and decreases with crack propagation in the intermediate layers of cobalt. The maximum stresses required for the destruction of the cobalt layer determine the strength of the entire microstructure. The strength of the alloy increases when decreasing pore diameter and increasing the cobalt phase fraction.

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].

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