Vibration modal analysis of three-dimensional and four directional braided composites

The composite has found extensive applications because of its excellent mechanical properties, but most conditions for the composite serving are subjected to dynamical loads. The parameters relevant to the performance under dynamical loads are system dynamical parameters, for example natural frequency, mode shape. For this aim, the three-dimensional (3D) and four directional braided composite was exemplified to explore the effect rule of the microstructure properties on the dynamical parameters. These macroscopic parameters are employed in discrete beam models and finite element models of continuous body to determine the natural frequencies and shapes. The simulation results were compared with experimental vibration modal analysis. Our study shows that the natural frequencies and shapes computed from both the discrete beam models and finite element models fit the experimental results well. This validates both our research approach and our theory from the microstructure properties to systematical dynamical properties.