Compression-Bending Load-Bearing Performance of Horizontal Joints in Wind Turbine Concrete Towers
This study investigates the compression-bending load-bearing performance of horizontal joints in wind turbine concrete towers through a 1:4 scaled compression-bending test on a concrete tower specimen. A finite element numerical model was established, and the simulated compression-bending capacity of the horizontal joint deviated from experimental results by less than 5%, validating the model's accuracy. The force mechanism of the horizontal joint in wind turbine concrete towers was systematically studied. Based on experimental results, theoretical cross-sectional force analysis, and finite element parametric analysis, a calculation method for the compression-bending capacity of horizontal joint connections under compression-bending conditions is proposed. The predicted values from this method deviate from experimental and finite element simulation results by less than 10%, further demonstrating the accuracy of the proposed calculation method. The study reveals that the failure mode of concrete towers under compression-bending loads exhibits brittle material failure, with concrete crushing on the compression side of the horizontal joint and yielding of longitudinal reinforcement. Existing design codes overestimate the compression-bending capacity of horizontal joints by a factor of approximately 1.7, leading to unsafe designs. The proposed method accounts for the actual force characteristics where ordinary tensile reinforcement remains unstressed and external prestressing strands remain uncompresssed, providing a more rational assessment of the flexural capacity of tower horizontal joints.