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Talks and Poster Presentations (without Proceedings-Entry):

M. Rodríguez-Hortalá, G. Requena, F. Sket, J. Molina-Aldareguia, E. Maire, L. Salvo, M. Scheel:
"3D Damage characterisation during sequential tensile loading of a multidirectional carbon fibre reinforced epoxy laminate (CFRP)";
Talk: European Congress and Exhibition on Advanced Materials and Processes: EUROMAT 2013, Sevilla (Spanien); 09-08-2013 - 09-13-2013.



English abstract:
Damage in carbon fibre reinforced polymer matrix composite laminates subjected to tensile stress is characterised by intra-laminar cracks, delamination between plies, fibre pull-out and fibre fracture. The aim of this work is to follow in-situ the formation and evolution of damage as well as the change in fibre orientation in a multidirectional carbon fibre reinforced laminate during tensile loading. The laminate was manufactured by hot pressing. Six prepreg-layers with a nominal thickness of 0.19 mm were stacked with a [+45/-45/+45]S lay-up. Synchrotron microtomography was carried out in-situ during tensile deformation of a notched sample with a notch radius of 1 mm and a cross section of aprox. 1 mm2 at the ID15A beamline of the European Synchrotron Radiation Facility. The first tomographic scan was performed using a preload of aporx. 5 MPa. Then, the sample was deformed stepwise using constant steps with a strain rate of 5 µm/s, nine tomographic scans were carried out at each deformation step until fracture. Volumes of 1017x1017x800 voxels with a voxel size of (1.4 µm)3 were obtained after reconstruction. Only one manufacturing pore was found within one of the plies, whose size 0.4∙106 μm3 represents 0.05 vol.%. Pre-existing cracks within plies dominate damage progression over manufacturing porosity. The change of orientation of the carbon fibres during tensile deformation was investigated individually for each ply. Fibres rotate about 2° aligning in the loading direction independently of the position of the ply within the laminate. The change in fibre orientation has been correlated to the damage taking place during deformation.

Keywords:
Synchrotron Microtomography; CFRP; Tensile Test; Damage Evolution

Created from the Publication Database of the Vienna University of Technology.