Modeling Approaches for 3D Orthogonal Woven Composites

Abstract

In this paper, a unit cell model and a laminate model are presented for predicting engineering elastic constants of 3D orthogonal woven composites. For the unit cell model, one finite element analysis (FEA) and four theoretical analytical approaches were proposed. In the FEA approach, a finite element mesh of a unit cell was generated by interfacing an in-house computer code with the commercial FEA software Strand6, and then used to investigate the effects of some geometrical parameters on engineering elastic constants and yarn volume fractions. In the theoretical approaches, all four analytical methods were developed using the elastic mechanics theory and "X model," "Y model" and "Z model" developed previously [1]. For the laminate model, one FEA modeling approach and one theoretical method were proposed by introducing three new lamina blocks. The finite element analysis of a laminate block was conducted using Strand6 and the theoretical method was developed using the same theory as the unit cell model above. The effect of the warp lamina block layer number on engineering elastic constants was discussed using the theoretical method. Good agreement between the FEA and theoretical analysis results were achieved for both the unit cell model and the laminate model. In addition, the in-plane Young's moduli El and E2 predicted using the unit cell and the laminate models correlated well with the experimental results available in the literature [2].