Damage onset mechanisms in multi-axial tensile test of 3D Woven Organic Matrix Composite through an in situ coupled micro-computed tomography and acoustic emission methodology

he present work studies the multi-axial damage onset mechanisms of 3D Woven Organic composite for aero-engine applications. For this purpose, an experimental methodology has been developed to detect the onset of damage by interrupting a tensile test. In situ observations have been performed through micro-Computed Tomography coupled with Acoustic Emission. The synergy between both experimental techniques relates the tomographic observable damage with the released acoustic energy levels succeeding in interrupting the tensile test at the damage initiation. The use of tomography has allowed a visual classification of the damage with respect to the meso-structure of the textile. Further, thanks to this methodology and by carrying out tests in different orientations of the textile and through the use of a Finite Element model at the homogeneous equivalent scale it is possible to identify the failure surface for the first damage of the material.