Finite element analysis of an interface crack with large crack-tip contact zones

Abstract There is considerable ambiguity regarding the limiting values of the strain energy release rate (SERR) components at the tips of a crack lying along the interface between two dissimilar isotropic media. In this paper this aspect is examined using finite element analysis and Modified Crack Closure Integral (MCCI) for a problem in which the material properties are chosen so as to cause a large size crack-tip contact zone. By careful choice of this problem, interpenetration of the crack faces in the crack-tip contact zones is observed for the first time in the finite element analysis. Earlier solutions primarily on remote mode 1 loading reported that SERR components do not converge as the virtual crack extension Δa → 0 and that these components show an oscillatory nature when Δa is less than the contact zone size rc. In the present work, multipoint constraints are imposed on crack face normal displacements in the contact zone and meaningful results are generated for both remote tension and shear loading cases. The apparent nonconvergence of the SERR components as Δa → 0 can be explained if these components are considered as functions of Δa, and Δa is considered as the actual crack growth step size.

[1]  M. Williams.  The stresses around a fault or crack in dissimilar media , 1959 .

[2]  G. B. Sinclair.  On the stress singularity at an interface crack , 1980 .

[3]  John Dundurs,et al.  The Interface Crack in a Tension Field , 1987 .

[4]  J. Willis,et al.  Fracture mechanics of interfacial cracks , 1971 .

[5]  Maria Comninou,et al.  The Interface Crack in a Shear Field , 1978 .

[6]  M. Toya,et al.  On mode I and mode II energy release rates of an interface crack , 1992 .

[7]  M. Kanninen,et al.  A finite element calculation of stress intensity factors by a modified crack closure integral , 1977 .

[8]  C. Sun,et al.  Strain energy release rates of an interfacial crack between two anisotropic solids under uniform axial strain , 1990 .

[9]  James R. Rice,et al.  Elastic Fracture Mechanics Concepts for Interfacial Cracks , 1988 .

[10]  B. Dattaguru,et al.  Finite element estimates of strain energy release rate components at the tip of an interface crack under mode I loading , 1994 .

[11]  I. Raju,et al.  Convergence of strain energy release rate components for Edge-Delaminated composite laminates , 1988 .

[12]  Maria Comninou,et al.  AN OVERVIEW OF INTERFACE CRACKS , 1990 .

[13]  Masayuki Toya,et al.  Fracture mechanics of interfaces , 1990 .

[14]  H. J. Grootenboer,et al.  A Finite Element Approach to Interface Cracks , 1986 .

[15]  C. Sun,et al.  On strain energy release rates for interfacial cracks in bi-material media , 1987 .

[16]  C. F. Shih,et al.  Mixed-Mode Interfacial Fracture Mechanics , 1991 .

[17]  John Dundurs,et al.  The Interface Crack Under Combined Loading , 1988 .

[18]  Maria Comninou,et al.  The Interface Crack , 1977 .

[19]  I. S. Raju,et al.  Simple formulas for strain-energy release rates with higher order and singular finite elements , 1986 .