Strength analysis of three-dimensional braided T-shaped composite structures

In this paper, based on the properties and strength analysis of the prestressed unit cell, the pull-off behaviors of the three-dimensional (3D) braided T-shaped composite structures are estimated by means of finite element method (FEM). First, a finite element model with Hashin’s failure criterion and maximum stress failure criterion is established to investigate the influence of the prestresses on the strength of the unit cell for the 3D four-directional braided composites. Second, the influences of the braided direction and fiber content on the strength of the unit cell for the 3D four-directional braided composites are discussed. Finally, based on the predicting results of the unit cell strength, the pull-off strength and damage characterizations of the 3D braided T-shaped composite structures is predicted using the Tsai–Hill failure criterion. The results will provide an important guidance for designing and evaluating damage and strength the 3D braided T-shaped composite structures.