Evaluation of vibration properties of three-dimensional, four-directional braided composites

This paper investigates the relationship between natural frequencies and different braiding parameters: the braiding angles and the fiber volume fractions for three-dimensional, four-directional (3D4d) braided composites. A systematic experiment was set up and conducted, and a corresponding finite element model was built to analyze the experimental results. Since the rate of change among the first three orders of natural frequencies for changing braiding parameters are strongly monotonous, only the first order is analyzed. Based on experimental data, the relationship between the natural frequencies of the first order and the two types of braiding parameters are compared and discussed. The findings suggest that the natural frequency of this material and its 3D4d structure can be designable.