Comparison of some improved solutions for mixed-mode composite delamination coupons

Four different solutions for the energy release rate of orthotropic, beam-like fracture specimens were compared in the present work. Two beam theory-based approaches were utilized. The current authors developed one of them, the other one was previously published in the literature. A model based on refined plate theory was also considered. Finally equations based on a numerical calibration technique were utilized as a fourth solution. These solutions were extended for the case of composite double-cantilever beam, end-loaded split, single-leg bending and mixed-mode bending fracture specimens. Comparison between the different solutions shows somewhat distinct results, especially for the mode ratio. There are some explanations for the experienced discrepancies between the mentioned solutions. (c) 2005 Elsevier Ltd. All rights reserved.