Multi-scale sensitivity analysis of structural vibration behaviors of three-dimensional braided composites with respect to material properties

Three-dimensional braided composites have a wide range of application in various industries. This article presents a three-step scheme enabling the multi-scale analysis of the vibration properties for three-dimensional braided composites. Firstly, a micro-scale model and meso‑scale mechanical model were constructed to predict the stiffness properties of the braided composites using both analytical and numerical methods. Secondly, the macro-scale vibration responses of the braided composites were carefully investigated both from analytical and numerical perspectives, followed by validation with experimental data. Thirdly, sensitivity analysis of the vibration properties, such as the modal frequencies, with respect to the braiding angle, fiber volume fraction, and braided structure was conducted. The results show that the macroscopic vibration properties strongly depend on the braiding angle, fiber volume fraction, and braided structure. Three-dimensional braided composites are quite promising for the integrated design of materials and structures, as their macroscopic structural vibration behaviors can be optimized by properly regulating their microscopic material characteristics.