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Download or read book Prediction of Stable Tearing of 2024-T3 Aluminum Alloy Using the Crack-Tip Opening Angle Approach written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-10-18 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the crack-tip opening angle (CTOA) approach was incorporated into a damage growth finite element program, MADGIC (Micromechanics Analysis and Damage Growth in Composites), and was used to predict stable tearing in a middle-crack tension 2024-T3 aluminum alloy specimen. The MADGIC code is a displacement based finite element program implemented with an incremental elastic-plastic algorithm used to model elastic-plastic behavior and a nodal splitting and nodal force relaxation algorithm used to generate crack surfaces. Predictions of the applied stress as a function of crack extension and applied stress as a function of load-line displacement were in good agreement with experiments and with similar predictions made using an existing finite element program, ZIP2D. In addition, path integrals, namely, the J-integral and T*-integral, were also evaluated and compared with the CTOA approach. There appears to be a weak relationship between the CTOA and the T*-integral evaluated on a specific integration path during crack extension beyond maximum applied stress. This study further verifies that the CTOA can be used as an effective elastic-plastic fracture mechanics parameter to predict crack growth. Bakuckas, J. G., Jr. and Newman, J. C., Jr. Langley Research Center RTOP 538-02-10-01...