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dc.contributor.advisorLubineau, Gilles
dc.contributor.authorTraudes, Daniel
dc.date.accessioned2012-07-24T06:55:17Z
dc.date.available2012-07-24T06:55:17Z
dc.date.issued2012-07
dc.identifier.doi10.25781/KAUST-2P7FI
dc.identifier.urihttp://hdl.handle.net/10754/235331
dc.description.abstractCarbon fiber based composites are an essential material in weight-critical applications such as in the aerospace industry. However, these materials are susceptible to damage such as matrix microcracking and fiber/matrix debonding (diffuse damage), which occurs at stresses much lower than the failure stress. A T700/M21 [0/90]s laminate was tensile loaded to introduce diffuse damage and prepared for a study on the initiation of transverse microcracks. The material was tensile loaded in a [+45/-45]s orientation to induce diffuse damage. A diffuse damage indicator was developed by measuring the decrease in shear stiffness. Samples with diffuse damage levels of 0, 0.05, 0.10, 0.15, 0.20, and 0.25 were prepared to be tensile tested in a [0/90]s orientation to induce microcracks. A successful development of the microcracking test procedure was performed. The edge of the material was studied with optical microscopy and x-ray to establish the structure of the fiber bundle geometry when undamaged. A sample containing microcracks was treated with diiodomethane dye penetrant, which successfully highlighted microcracks during x-ray imaging. The application time was not sufficient to produce consistent x-ray images over time, so a 45 minute soak time was recommended instead. The same damaged sample was subjected to a tomographic scan without a dye penetrant and while unloaded. Transverse microcracks were successfully identified from the data, although the results were not clean enough and likely omitted some smaller microcracks. Results are expected to be cleaner if performed during tensile testing. Future tensile testing will quantify the induced crack density of samples containing various degrees of initial diffuse damage, either using x-rays with a dye penetrant or using x-ray microtomography.
dc.language.isoen
dc.subjectComposites
dc.subjectTomography
dc.subjectIn situ
dc.subjectDiffuse
dc.subjectCFRP
dc.subjectMicrocrack
dc.titleIn Situ Tomography of Microcracking in Cross Ply Carbon Fiber Composites with Pre-existing Debonding Damage
dc.typeThesis
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberAmassian, Aram
dc.contributor.committeememberFarooq, Aamir
thesis.degree.disciplineMechanical Engineering
thesis.degree.nameMaster of Science


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