A developed Fick's law and HSV-based fatigue reliability modeling method for CFRP/Epoxy adhesive structures considering environmental stresses and size effects

This manuscript, set against the backdrop of offshore wind turbine blades, focuses on the adhesive structure of carbon fiber and epoxy resin. By incorporating Fick's law and the High Stress Volume (HSV) method, a fatigue analysis and fatigue reliability modeling approach for adhesive structures under multi-environmental stresses, considering size effects, is proposed. This study applies Fick's law to analyze material moisture diffusion and assesses adhesive layer failure in aged samples. It develops a probabilistic fatigue life prediction model using the HSV method, delving into the fatigue degradation of adhesive structures. Through environmental aging and fatigue testing on CFRP/Epoxy adhesive structures revealed that extreme conditions of temperature, humidity, and salt fog expedite epoxy corrosion, diminishing load-bearing capacity and shortening the fatigue life. The study highlights that the aging environment, along with adhesive length and thickness, profoundly influence the performance of these structures. The model's predicted results have an average error of less than 5 % compared to experimental values, validating the feasibility of the proposed method. Furthermore, this research provides a theoretical basis for the life prediction and maintenance of offshore wind turbine blades.