Modeling of damage in unidirectional ceramic matrix composites and multi-scale experimental validation on third generation SiC/SiC minicomposites

Abstract

International audienceThe purpose of this paper is to experimentally validate a 1D probabilistic model of damage evolution in unidirectional SiC/SiC composites. The key point of this approach lies in the identification and validation at both local and macroscopic scales. Thus, in addition to macroscopic tensile tests, the evolution of microscopic damage mechanisms - in the form of matrix cracks and fiber breaks - is experimentally analyzed and quantified through in-situ scanning electron microscope and computed tomography tensile tests. A complete model, including both matrix cracking and fiber breaking, is proposed on the basis of existing modeling tools separately addressing these mechanisms. It is based on matrix and fiber failure probability laws and a stress redistribution assumption in the vicinity of matrix cracks or fiber breaks. The identification of interfacial parameters is conducted to fit the experimental characterization, and shows that conventional assumptions of 1D probabilistic models can adequately describe matrix cracking at both macro- and microscopic scales. However, it is necessary to enrich them to get a proper prediction of ultimate failure and fiber break density for Hi-Nicalon type S fiber-reinforced SiC/SiC minicomposites

Analysis of the damage initiation in a SiC/SiC composite tube from a direct comparison between large-scale numerical simulation and synchrotron X-ray micro-computed tomography

“…Although 1D modeling of such a phenomenon is now well established (see e.g. [69,70] On the other hand, as any experimental approach, the DVC-based crack detection technique also suffered its limitation: only the cracks with an opening larger than 0.5 µm could be captured. Therefore, it is likely that some cracks are missing, whether they opened at damage initiation or after.…”

A finite fracture model for the analysis of multi-cracking in woven ceramic matrix composites

“…The axial tensile behavior of unidirectional ceramic matrix composites has been analyzed in the literature [14][15][16]. The elastic response is characterized by a modulus…”

Damage evolution in SiC/SiC unidirectional composites by X‐ray tomography

“…Other nondestructive methods, such as acoustic emission (AE) and electrical resistance have been utilized to study the types of damage that occur in CMCs under various types of loading and environmental conditions . The use of X‐ray computed microtomography to observe damage in various types of CMCs has proven to be a valuable nondestructive techniques …”