Biaxial tensile properties of reinforcements in composites

The deformability of acomposite reinforcement depends onitsinternal structure and has a relevant influence on the quality of the composite part. Among the mechanical features of a composite reinforcement, the bi-axial behaviour plays an important role on its capability to drape a complex shape. In this chapter the methodologies employed to measure and to predict the bi-axial behaviour of composite reinforcements are discussed. The features of some experimental devices adopted to investigate the response to bi-axial loading of composite reinforcements are detailed. A prediction tool based on an analytical model of a plane weave reinforcement is briefly described and compared to experimental data. Finally, the characteristics of reliable numerical models, based on the finite element method, are highlighted in terms of information obtained at macro and meso-scale.