On mode I and mode II energy release rates of an interface crack

1992 ◽  
Vol 56 (4) ◽  
pp. 345-352 ◽  
Author(s):  
M. Toya
Keyword(s):  
Energy Release ◽  
Interface Crack ◽  
Mode I ◽  
Mode Ii ◽  
Release Rates ◽  
Energy Release Rates

Energy Release Rates for an Interface Crack Embedded in a Laminated Beam Subjected to Three-Point Bending

1997 ◽  
Vol 64 (2) ◽  
pp. 375-382 ◽  
Author(s):  
M. Toya ◽  
M. Aritomi ◽  
A. Chosa
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Interface Crack ◽  
Release Rate ◽  
Mode I ◽  
Mode Ii ◽  
Release Rates ◽  
Three Point Bending ◽  
Axial Forces ◽  
Energy Release Rates

Asymmetric three-point bending of a layered beam with an interface crack is analyzed on the basis of the classical beam theory. Axial forces induced by bending in the parts of the beam above and below the delamination are determined by regarding the cracked part as two lapped beams hinged at both ends. The compliance and the energy release rate are then derived. Numerical analyses based on the finite element method are carried out, which show that delamination growth occurs in mixed mode, i.e., both the normal separation (mode I) and mutual sliding (mode II) of the crack surfaces contribute to the fracturing process. Finally the decomposition of the energy release rate into mode I and mode II components is made by combining the analysis of the energy release rates by Toya (1992) and the two-dimensional linear beam solutions by Suo and Hutchinson (1990).

The Characterization of Mixed-Mode Energy Release Rates in Orthotropic Materials

1996 ◽  
Vol 210 (1) ◽  
pp. 33-42 ◽  
Author(s):  
C A Walker ◽  
Jamasri
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Energy Release ◽  
Crack Growth ◽  
Release Rate ◽  
Mode I ◽  
Mode Ii ◽  
Finite Element Models ◽  
Release Rates ◽  
Energy Release Rates

The aim of this work was to predict, from the material constants, mixed-mode energy release rates in orthotropic materials, in particular the general cases in which the crack is aligned at a random angle to the principal material direction, normal to the plane of orthotropy. Two-dimensional finite element models with various fibre orientations were generated. The finite element models were validated by comparing two sets of contour plots of deformation, one resulting from the finite element analysis and the other from moiré interferograms of the experimental work. On comparison there was shown to be a strict similarity between experimentally determined and computational deformation fields. Variations of the energy release rates were investigated for both rapid and stable crack growth. This was accomplished by generating two-dimensional stable crack growth finite element models. In general, energy release rates were found to be strongly affected by the fibre orientation. An increase of the angle of the crack growth direction caused a decrease of the mode I energy release rate and, by contrast, an increase of the mode II energy release rate, but the mode II energy release rate was always a small fraction of the mode I value. Crack extension caused a gradual increase of the mode I energy release rate both for coplanar and non-coplanar crack growth. However, there was no significant effect found on the mode II energy release rate.

scholarly journals Geometrically Nonlinear Analysis of Adhesively Bonded Joints

1984 ◽  
Vol 106 (1) ◽  
pp. 59-65 ◽  
Author(s):  
B. Dattaguru ◽  
R. A. Everett ◽  
J. D. Whitcomb ◽  
W. S. Johnson
Keyword(s):  
Energy Release ◽  
Strain Energy ◽  
Strain Energy Release ◽  
Mode I ◽  
Mode Ii ◽  
Geometrically Nonlinear ◽  
Release Rates ◽  
Lap Shear ◽  
Energy Release Rates ◽  
Strain Energy Release Rates

A geometrically nonlinear finite-element analysis of cohesive failure in typical joints is presented. Cracked-lap-shear joints were chosen for analysis. Results obtained from linear and nonlinear analysis show that nonlinear effects, due to large rotations, significantly affect the calculated mode I, crack opening, and mode II, inplane shear, strain-energy-release rates. The ratio of the mode I to mode II strain-energy-release rates (GI/GII) was found to be strongly affected by the adhesive modulus and the adherend thickness. GI/GII ratios between 0.2 and 0.8 can be obtained by varying adherend thickness and using either a single or double cracked-lap-shear specimen configuration. Debond growth rate data, together with the analysis, indicate that mode I strain-energy-release rate governs debond growth. Results from the present analysis agree well with experimentally measured joint opening displacements.

Energy Release Rates for an Edge Delamination of a Laminated Beam Subjected to Thermal Gradient

2004 ◽  
Vol 72 (5) ◽  
pp. 658-665 ◽  
Author(s):  
M. Toya ◽  
M. Oda ◽  
A. Kado ◽  
T. Saitoh
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Temperature Difference ◽  
Release Rate ◽  
Mode Ii ◽  
Pure Mode ◽  
Release Rates ◽  
Laminated Beam ◽  
Energy Release Rates ◽  
Edge Delamination

Energy release rates for an edge delamination of a laminated beam subjected to through-thickness temperature gradient are analyzed on the basis of the classical beam theory. The decomposition of the energy release rate into mode I and mode II components is made by combining the analyses of the energy release rates by Toya (1992) and the two-dimensional elasticity solutions for a split-beam element by Suo and Hutchinson (1990). The energy release rate is a quadratic function of the temperatures of the top and bottom surfaces of the beam. The transition of the type of crack growth between pure mode II and mixed mode type occurs at the temperature difference corresponding to the minimum energy release rate. Numerical analyses based on finite-element method are also carried out, which show that the theory agrees well with numerical results when temperature jump across the delaminated surfaces is relatively small as compared with the temperature difference between the top and bottom surfaces of the layered beam.

On Energy Release Rates and Configurational Forces for Interfacial Propagating Cracks: A Lattice Approach With a Brittle Erosion Technique

2016 ◽  
Vol 84 (2) ◽  
Author(s):  
Amir Mohammadipour ◽  
Kaspar Willam
Keyword(s):  
Energy Release ◽  
Interface Crack ◽  
Driving Forces ◽  
Configurational Forces ◽  
Bimaterial Interface ◽  
Release Rates ◽  
Material Forces ◽  
Energy Release Rates ◽  
Crack Tips ◽  
Lattice Approach

A numerical 2D lattice approach with an erosion algorithm is employed to analyze bimaterial interface fracture quantities in brittle heterogeneous materials in the context of linear elastic fracture mechanics (LEFM). The concept of configurational force is elucidated and the importance of nodal configurational changes in a mesh where no stress–strain analyses are needed is investigated. Three fracture problems, i.e., an infinite panel with a bi-material interface crack, a double-lap shear test, and a prenotched four-point bending masonry beam are then considered. Validated by analytical solutions, the lattice model uses two distinct postprocessing approaches to derive the energy release rates and configurational forces directly at bimaterial interface crack tips. While the first method takes advantage of the change of the lattice mesh's global stiffness matrix before and after crack growth without any stress–strain calculations to obtain crack tip driving forces, the second approach analyzes the configurational forces opposing the crack tip motion using the Eshelby stress tensor and local force balance law in cracked and heterogeneous domains. It is demonstrated that the discrete material forces at crack tips are closely equal to the tip driving forces for the three fracture problems, confirming that the lattice is an appropriate numerical tool to analyze fracture properties of evolving interface cracks. Satisfying C1 continuity by including rotational displacements for frame struts, there is also no need for the lattice to update interior computational points in the mesh to eliminate spurious material forces away from the tip.

Sign in / Sign up

Export Citation Format

Share Document