Analytical Models for Prediction of the Thermoelastic Properties of 3-D Braided Composites: A Review

In the available analytical models for the prediction of clastic properties of 3-D braided composites, aside from differences in the identified internal structure of the preform, many assumptions and approximations have been introduced and therefore different solutions are available. Many of these models are based on an idealized “unit cell” which takes the form of a parallelpiped, with lines which represent the braiding yarns connecting the opposite corners along the body diagonals. The braided composite is regarded as being made up of repetition of these unit cells. However, more recent research has demonstrated that the 3 D braided composite is not homogeneous and that the fiber architectures in the interior, boundary, and the corner of the braided composite are different. In this paper some of the existing analytical models for 3 D braided composite are briefly reviewed and a summary of their concept, assumptions, and methodology is given. The results of recent research which identifies the three dimensional fiber architecture of 3 D braided composite are also demonstrated. The 4 Step (1x1) braiding is used as an example. Finally, a finite element based method for modeling the behavior of 3 D braided composite is described briefly and some of the predictions of this modeling approach that have been published before are presented.