Mechanics of three-dimensional braided structures for composite materials ¯ Part II: prediction of the elastic moduli

In the first part of this series of paper [Z.X. Zang, R. Postle, Mechanics of threedimensional braided structures for composite materials ¯ Part I: fabric structure and fibre volume fraction, Comp. Struct. 49 (2000) 451¯459], it was demonstrated that the braiding angles and fibre volume fraction can be represented as functions of the normalized pitch length introduced as a key parameter of three-dimensional braided reinforced composite materials. In the present paper, the models for the prediction of the tensile and shear moduli of three-dimensional braided composites are established by numerical simulation and mathematical modelling. Three-dimensional braided preforms are produced from the material system comprising glass/polypropylene and their moduli are measured. The results predicted from the braided composite models are supported by the experimental data