Predictive strength-fracture model for composite bonded joints

Abstract A new strength-fracture model is proposed for the formulation of decohesion elements, which are implemented in finite element models to predict failure of bonded joints. The proposed model unifies criteria for strength to predict failure initiation and criteria for fracture to predict failure progression. The initiation and progression of interfacial cracks and/or cohesive cracks are simulated by positioning decohesion elements at the adherend–adhesive interface and between bulk adhesive elements. Geometric nonlinearity of the adherends and adhesive are included in the finite element formulation. Simultaneous cracks and their paths are predicted for static equilibrium configurations of the following joint configurations: double cantilever beam, single lap joint, and the crack lap shear. Qualitative and quantitative between finite element analyses predictions and experimental results for quasi-static loading of these joint configurations were found to be in general agreement.

[1]  H. Saunders,et al.  Advanced Fracture Mechanics , 1985 .

[2]  K. Wang,et al.  Stress singularities at interface corners in bonded dissimilar isotropic elastic materials , 1971 .

[3]  Carlos G. Davila,et al.  Irreversible constitutive law for modeling the delamination process using interfacial surface discontinuities , 2004 .

[4]  Viggo Tvergaard,et al.  On the toughness of ductile adhesive joints , 1996 .

[5]  M. D. Moura,et al.  Mixed-Mode Decohesion Elements for Analyses of Progressive Delamination , 2001 .

[6]  David B. Bogy,et al.  Edge-Bonded Dissimilar Orthogonal Elastic Wedges Under Normal and Shear Loading , 1968 .

[7]  Carlos G. Davila,et al.  An Irreversible Constitutive Law for Modeling the Delamination Process Using Interface Elements , 2002 .

[8]  Naveen Rastogi,et al.  Stress analysis codes for bonded joints in composite structures , 1997 .

[9]  A. Needleman.  A Continuum Model for Void Nucleation by Inclusion Debonding , 1987 .

[10]  V. Goyal,et al.  INTERPHASIC FORMULATION FOR THE PREDICTION OF DELAMINATION , 2004 .

[11]  Olivier Allix,et al.  Identification and forecast of delamination in composite laminates by an interlaminar interface model , 1998 .

[12]  M. Williams,et al.  Stress Singularities Resulting From Various Boundary Conditions in Angular Corners of Plates in Extension , 1952 .

[13]  Shankar Mall,et al.  A fracture mechanics approach for designing adhesively bonded joints , 1985 .

[14]  Damodar R. Ambur,et al.  Intralaminar and interlaminar progressive failure analyses of composite panels with circular cutouts , 2002 .

[15]  Jan G. Rots,et al.  Occurrence of spurious mechanisms in computations of strain‐softening solids , 1989 .

[16]  J. Hutchinson,et al.  The influence of plasticity on mixed mode interface toughness , 1993 .

[17]  R. Salganik,et al.  The strength of adhesive joints using the theory of cracks , 1984 .