In composite reinforcement shaping, textile preform undergo biaxial tensile deformation, in plane shear deformation, transverse compaction and outof-plane bending deformations. Bending deformations have been neglected in some simulation codes up to now, but taking into account them would give more accurate simulations of forming especially for stiff and thick textiles. Bending behaviour is specific because the reinforcements are structural parts and out of plane properties cannot be directly deduced from in-plane properties, like for continuous material. Because the standard tests are not adapted for stiff reinforcements with non linear behaviour a new flexometer using optical measurements has been developed to test such reinforcements. This new device enables to carry out a set of cantilever tests with different histories of load. A series of tests has been performed to validate the test method and to show the capacities of the new flexometer to identify non linear non elastic behaviour.

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A finite element simulation of composite woven reinforcement forming requires the knowledge of the fabric mechanical behaviour. In the presented mesoscopic approach, the tensile and shear mechanical behaviour of the elementary cell (mesoscopic level) are used in a finite element made of woven meshes. The principal stiffness of the fabric is the tensile rigidity. Because of the weaving, the tensile behaviour is non-linear. It is analysed by biaxial tensile tests and 3D finite element computations of the woven unit cells. The in plane shear rigidity of fabrics is very weak up to a limit angle. In this first stage, it is shown by optical measures that the yarns are subjected to rigid rotations. A second stage in which the yarns are laterally crushed leads to larger stiffness. A first simplified form of the dynamic equation is based only on tensile internal virtual work. A second one takes also shear internal work into account. A fabric square box forming simulation is performed with both approaches. It shows the importance to account for shear when the limit shear angle is exceeded.

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