Meso-scale (unit cell of an impregnated textile reinforcement) finite element (FE) modelling of textile composites is a powerful tool for homogenisation of mechanical properties, study of stress-strain fields inside the unit cell, determination of damage initiation conditions and sites and simulation of damage development and associated deterioration of the homogenised mechanical properties of the composite. Meso-FE can be considered as a part of the micro-meso-macro multi-level modelling process, with micro-models (fibres in the matrix) providing material properties for homogenised impregnated yarns and fibrous plies, and macro-model (structural analysis) using results of meso-homogenisation. The paper discusses stages of the meso-FE analysis and proposes a succession of steps (''road map'') and the corresponding algorithms for it: (1) Building a model of internal geometry of the reinforcement; (2) Transferring the geometry into a volume description (''solid'' CAD-model); (3) Preparation for meshing: correction of the interpenetration of volumes of yarns in the solid model and providing space for the thin matrix layers between the yarns; (4) Meshing; (5) Assigning local material properties of the impregnated yarns and the matrix; (6) Definition of the minimum possible unit cell using symmetry of the reinforcement and assigning periodic boundary conditions; (7) Homogenisation procedure; (8) Damage initiation criteria; (9) Damage propagation modelling. The ''road map'' is illustrated by examples of meso-FE analysis of woven and braided composites.

Damage in textile composites is closely connected with the internal micro-and meso-geometry of the reinforcement, and reveals features, which are not present in the damage processes in classical laminates. This paper proposes a test sequence intended to characterise damage in textile composites -its initiation and development different scale levels: (1) Tensile tests on samples cut in characteristic directions of the textile reinforcement (machine, cross and bias), accompanied with acoustic emission (AE) registration and full-field strain measurement on the surface. The test produces stress-strain diagrams and identifies characteristic strain levels for post-mortem investigation: just after first damage e 1 ; well-developed damage e 2 ; just before the final fracture of the sample e 3 . Full-field strain measurement highlights the relation between strain concentrations (linked with the damage initiation) and the reinforcement structure. (2) Samples loaded up to e 1. . .3 are examined with CT and X-ray. This reveals the damage pattern and allows quantitative characterising of the damage development.(3) Optical and SEM examination of cross-sections through the damage sites, determined with X-ray, identifies local damage modes. The same strain levels are further used for setting up fatigue tests. The experimental protocol is applied for triaxial braided and quasi-UD composites.

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