# Comparative Study on Vibration Characteristics of Biaxial Carbon/Glass Hybrid Wind Turbine Blades
## 1 Introduction
[20] simplified the wind turbine blade as a variable cross-section Euler-Bernoulli cantilever beam rotating around the hub for nonlinear flapping analysis. [PERSON] [21], based on the two-way fluid-structure interaction method, analyzed that the blade deformation is mainly concentrated at the tip, and the blade deformation is mainly waving along the axial direction. When the blades are under different inflow conditions they are mainly subjected to axial forces [22] and the coupled displacement response amplitude gradually increases along the blade span direction, resulting in an increase in inflow velocity and amplitude [23]. [PERSON] [24] analyzed the composite laminated shell structure of 10 kW wind turbine blades and found that the blade displacement increased with the increase in aerodynamic force, but when the blade reached its maximum speed it was within the safe range. In addition, researchers are committed to exploring fluid-structure interaction vibration of wind turbine blades under different working conditions [25], bending torsional coupling vibration and fault diagnosis [26; 27]. The above literature mainly focuses on research methods, ideas, and analysis of blade vibration characteristics. However, the content focuses on the variation patterns of blade displacement and natural frequency, and there is less analysis of blade vibration characteristics based on stress distribution. In this paper, carbon/glass hybrid-fiber reinforced composite laminates were prepared via vacuum assisted resin transfer molding. Their Poisson's ratio and elastic modulus were obtained through experiments, and were imported into the ANSYS software (2022R1) for modeling. Based on the overall dynamic balance equation of the structure, fluid-structure interaction and modal analysis were carried out for the blade, and the blade load distribution and deformation were studied. At present, carbon fiber material blades and glass fiber material blades have been put into production and use. Carbon fiber materials have excellent performance, and their seismic resistance and deformation resistance are far greater than those of glass fiber wind turbine blades. However, due to the high cost of carbon fiber wind turbine blades, their universality is not strong. In contrast, carbon glass hybrid fiber blades have improved performance and lower cost compared to glass fiber material blades, which is expected to replace traditional blade materials. Therefore, analyzing the vibration characteristicsof carbon glass fiber hybrid blades can help scholars further understand the material and provide further reference for the actual production and use of the blade. This article produces three different carbon glass hybrid ratio specimens through experiments, measures their mechanical properties, uses Ansys software to model a 10 kW blade, and establishes a flow field for modal analysis and bidirectional fluid structure coupling analysis of the blade. These analysis methods can help engineers evaluate whether the designed structure is reasonable. This article aims to use modal analysis and fluid structure coupling analysis to study the characteristics of the designed blades. Through modal analysis, we can understand the natural frequencies and vibration modes of different blades. The fluid solid coupling analysis investigated the influence of fluid on the modal and deformation of blades with different carbon glass hybrid ratios. Through these analyses, engineers can better understand the performance of carbon glass hybrid blades under actual working conditions.