0000000000308846
AUTHOR
A. Thionnet
Multi-scale analysis to determine fibre/matrix debonding criteria in SiCTitanium composites with and without consideration of the manufacturing residual stresses
Abstract Certain dissipative phenomena in long-fibre composites are still quite poorly understood, especially the debonding between the fibre and the matrix. The present study is an attempt to elucidate this phenomenon in SiC Titanium metal-matrix composites. The phenomenon is analysed both experimentally and numerically, both on the scale of the constituents and on the scale of the equivalent homogeneous material. This leads to the identification of a local debonding criterion which helps to determine a global debonding criterion. This approach is made for two cases, without and without consideration of the manufacturing residual stresses.
Multi-scale modelling of heterogeneous shell structures
International audience; This paper reviews multi-scale computational homogenisation frameworks for the non-linear behaviour of heterogeneous thin planar shells. Based on a review of some of the currently available methods, a computational homogenisation scheme for shells is applied on to representative volume elements for plain weave composites. The effect of flexural loading on the potential failure modes of such materials is analysed, focusing on the reinforcement-matrix delamination mechanism. The attention is next shifted toward failure localisation in masonry unit cells. Subsequently, a recently developed computational FE2 solution scheme accounting for damage localisation at structura…
Fibre break failure processes in unidirectional composites: evaluation of critical damage states
Earlier work which successfully modelled the kinetics of fibre breakage in unidirectional composites under monotonic tensile loading has been extended to quantify the kinetics of fibre failure during both monotonic and sustained tensile loading. In both cases, failure was seen to occur when a critical density of large clusters (more than 16 fibres are broken within the representative volume element) of fibre breaks developed. However, in monotonic loading failure occurred very quickly after the first development of these large clusters, whereas under sustained loading the composite could accommodate greater levels of large clusters because of the lower applied load. This article is part of …
A theoretical and experimental study to point out the notion of loading mode in damage mechanicsApplication to the identification and validation of a fatigue damage modeling for laminates composites
A model of fatigue-induced intralaminar cracking in strongly anisotropic laminates is presented. The features of the microscopic phenomenon are explicitly taken into account at the macroscopic level by the use of two variables, which define a new concept in Damage Mechanics that results not only in a coherent model of crack density evolution, but also in a coherent treatment of damage deactivation. Damage evolution indeed is strongly dependent on the local loading mode in each ply where cracking occurs. Experiments on complex lay-ups provided sufficient data for complete calibration of the model. These tests also allowed to validate the theoretical choice of the damage variable. Finally, nu…