Mechanics of three-dimensional braided structures for composite materials – part III: nonlinear finite element deformation analysis

In the previous two parts of this series of papers, the fabric structures of three-dimensional braided composites were simulated and the fibre volume fraction was derived [Z.X. Tang, R. Postle, Compos. Struct. 49 (2000) 451]. The models of tensile and shear moduli for three-dimensional braided composites were established by computer simulation and mathematical modelling. The results predicted from the modulus models were supported by the experimental data [Z.X. Tang, R. Postle, Compos. Struct. 51 (2001) 451]. In the present paper, a nonlinear finite element approach used for simulating and analysing the deformation of three-dimensional braided composites is derived. The corresponding computer codes are developed with 20-node hexahedral elements and 3×3×3 Gauss–Legendre quadrature. The tension and bending simulations are performed. The comparisons of the results obtained from simulation, experiment and prediction from the modulus models are reported. The results of simulation are supported by the experimental data and the values predicted by the previously published modulus models.