Experimental and numerical investigations on the tensile behavior of 3D random fibrous materials at elevated temperature

Using experimental method and Finite Element Method (FEM) in this paper, we studied the mechanical behaviors of the three-dimensional (3D) random fibrous (RF) material under tensile loadings in the through-the-thickness (TTT) and in-plane (IP) directions at elevated temperatures. It is interestingly found from the experiments that the fracture strength of 3D RF material in the TTT and IP directions doesn't follow the convention that the strength decreases as increasing temperature. Such a different variation trend of the fracture strength in the two directions is attributed to the presence of residual stress inside the material arisen from the fabrication process. In addition, Young's modulus of the 3D RF material in the TTT and IP directions decreases with the temperature. These observations from the experiment are in good agreement with the numerical results from the 3D FEM modeling of the 3D RF material developed in this paper.