## 1 Introduction  
As the key components of wind turbine systems, wind turbine blades entail high costs for manufacturing, transportation, and maintenance, particularly in remote areas. Therefore, long-term structural reliability is crucial [1; 2; 3; 4; 5]. Wind turbine blades are generally manufactured using a vacuum infusion method, wherein the fiber materials pre-placed in the mold are synthesized and bonded together, as shown in Figure 1. During the actual manufacturing process of composite materials, due to significant manual intervention, defects are inevitably introduced [6; 7; 8; 9; 10]. These minor defects, under the influence of complex environments and alternating loads, gradually lead to crack propagation, severely impacting the operational safety of wind turbine blades. Due to the complexity and large size of wind turbine blade structures, it is challenging to study crack propagation in full-size cracked blades [11; 12]. This paper aims to establish and prepare cracked carbon-fiber structures for fatigue analysis to provide a basis for the application of carbon-fiber composites in wind turbine blades. The existing literature has accumulated extensive experience in the simulation analysis and experimental testing of cracked fiber composites. In simulation, [PERSON] et al. [13] developed a new multiphase field (MPF) model combined with the cohesive zone model (CZM), effectively simulating the interaction between intralayer and interlayer cracking in cracked fiber-reinforced composite panels, significantly improving the ability to predict the fatigue life for complex failure modes. [PERSON] et al. [14] studied the dynamic fatigue-crack propagation in cracked carbon-fiber panels under non-classical thermal shock conditions based on the Lord-Shulman theory. They used a domain-independent interaction integral method to calculate the stress intensity factor of dynamic cracks and simulated it using the extended finite element method (XFEM). [PERSON] et al. [15] applied the three-dimensional Hashin failure criterion, combining UMAT and VUMAT subroutines, to analyze the mechanical behavior and fatigue failure modes of cracked glass fiber composite panels under different strain rates, demonstrating the model's predictive capability under various loading conditions. Experimentally, [PERSON] et al. [16] explored the crack resistance of cracked fiber-reinforced composite panels through three-point bending tests and microstructure analysis, providing quantitative evaluations of the material's tensile strength and fracture toughness. [PERSON] et al. [17] combined experimental and numerical methods to study the fracture behavior of cracked carbon-fiber panel beam structures under four-point loading, using different carbon-fiber composite arrangements and analyzing the fatigue failure mode of crack propagation using the J-integral method, revealing the dominant failure mechanisms of skin crack extension and its impact on the structures' structural integrity. [PERSON] et al. [18] analyzed the vibration characteristics of single-crack and multi-crack blade disc systems using orthogonal experiments, studying the effects of the crack depth, height, and rotational speed on their vibration, and evaluated the role of crack distribution. In summary, this paper focuses on cracked carbon-fiber structures to study the influence of material parameters, cracks, and loads on fatigue reliability. Numerous parameters affect the fatigue reliability of carbon-fiber structures. Therefore, understanding the impact of each parameter on their structural reliability and identifying the most critical ones can provide clear guidance for designing and manufacturing wind turbine blades [19; 20]. Due to the high computational cost of sensitivity analysis, most studies adopt surrogate model-based methods. [PERSON] et al. [21] employed random forests as a non-parametric method and combined them with a metamodel for efficient sensitivity analysis.