## 4 Conclusions  
The influences of trailing-edge structural configurations on the shear fatigue life of the trailing-edge adhesive joint were investigated in this study using the finite element and STM methods. The fatigue properties of the adhesive were obtained by laboratory tests. The fatigue properties under different stress ratios were obtained by constant-amplitude life curve interpolation. The transformation matrices were obtained by applying a unit load to the finite element model. The software GH BLADED was used to obtain the time-series of blade dynamic loads. Shear fatigue damage of the structural adhesive was obtained from the stress time-series curve and constant-amplitude life curve. The four structural configurations related to the bonding of the trailing edge had an obvious influence on the fatigue shear life of the bonding. * The angle of chamfer affected mainly the damage of the beginning of the bonding line. If the angle of the chamfer near the bonding surface was acute, the damage increased. If the angle of chamfer near the bonding surface was obtuse, the damage reduced. The results showed that a fillet at the beginning of the bonding line in the process of blade generation is beneficial to reduce the maximum damage. If the excess adhesive could be scraped away and a certain chamfer could be formed in the production, it was very beneficial to the blade structure. On the one hand, the unnecessary weight in the blade could be reduced. On the other hand, the stress concentration of the bonding line could be reduced, thus minimizing the damage and improving the reliability of the adhesive. * The position of UD affected mainly the damage of the middle region of the bonding area. The peak value of damage in the middle region changed with the movement of the UD position. The value of the valley of the middle region moved toward the leading edge along with UD positioning, and the value of the valley was lower as it moved toward the leading edge. However, adjusting the damaged distribution of the trailing-edge adhesive by adjusting the position of the trailing-edge UD in the actual blade structure design was almost impossible. The calculation results might help understand the effect of UD positioning on shear fatigue damage of the trailing-edge adhesive. * The stiffness of prefabricated bonding components affected the uniformity of adhesive damage. The greater the stiffness, the more uniform the damage distribution. Therefore, in the design of  
Figure 22: Comparison of the benchmark and OL models on each layer: (**a**) Comparison of the results of layer 1 in each model; (**b**) Comparison of the results of layer 2 in each model; (**c**) Comparison of the results of layer 3 in each model; (**d**) Comparison of the results of layer 4 in each model; (**e**) Comparison of the results of layer 5 in each model. the blade structure, the prefabricated bonding components with higher stiffness should be used if possible, thus effectively reducing the maximum damage extreme value. * The outer over-lamination of the end of the bonding line could effectively reduce the shear damage of the structural adhesive and affect 20% of the bonding width. Therefore, placing the outer over-lamination at the end of the tailing-edge bonding line after the blade was demolded and maintained as necessary. This study systematically explored the influence of four structural configurations related to the trailing-edge structural adhesive on the shear fatigue damage. The findings might help engineers to understand the mechanical behavior in the process of blade design and maintenance to a certain extent, thus contributing to reducing the failure rate of blades and the maintenance cost of wind turbines. [PERSON] performed the calculations and tests and wrote the manuscript. [PERSON] and [PERSON] checked the calculation results, and [PERSON] helped analyze the results. All authors have read and agreed to the published version of the manuscript. This study was funded by the National Key R&D Program of China (Grant no.