| Autor: |
John C. Klug, Vinay K. Goyal |
| Rok vydání: |
2004 |
| Předmět: |
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| Zdroj: |
45th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials Conference. |
| DOI: |
10.2514/6.2004-1845 |
| Popis: |
A stress-strain delamination constitutive law based on a continuum damage mechanics formulation is postulated for the thin resin layer that exists between adjacent composite laminae to predict initiation and growth of delamination. Delamination is predicted to initiate based on a interlaminar maximum stress obtained from a multiaxial stress criterion and the delamination front is predicted to advance based on a critical fracture energy obtained from a mixed mode fracture criterion. Damage is assumed to be irreversible via the inclusion of a thermodynamically consistent damage parameter. The damage parameter is directly related to the dissipated fracture energy. Although the implementation of the constitutive law in a commercial finite element code is straightforward, the nonlinear solver often fails to converge to a solution using the conventional tangent stiffness matrix. Convergence is achieved by using a stiffness matrix with a modification that improves its condition number. With this novel constitutive law and stiffness modification, the delamination front and the direction of delamination propagation are predicted for various fracture test configurations such as the double cantilever beam, end load split, and end crack torsion. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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