Comparative Analysis on Damage Mechanism of Two New Types of Concrete Filled Steel Tubular Lattice Wind Turbine Tower Joints

This research was to find a more suitable joint form for the concrete filled steel tubular lattice wind power tower，two split spherical joints and two ellipsoidal joints were designed，and then the static test was conducted. Firstly，the failure mode of the two joints，the load-deformation curve of the web member，the stress distribution of the ball table，and the plate area of the ball table were compared and analyzed by controlling the change of the wall thickness of the ball table. Moreover，the parameters were expanded by ABAQUS. The results showed that the failure mode of the split spherical joint was the material strength failure and the plate buckling failure of the platform. Besides，the failure modes of ellipsoidal joints were the tear failure of the ball press plate and the bolt thread failure，and the elliptical joint showed higher ultimate bearing capacity. Compared with ellipsoidal joints，the stress distribution of split spherical joints was more uniform，the stress range was smaller，the material utilization rate was higher and the economy was better. When the wall thickness of the ball table increased from 6 mm to 10 mm，the ultimate bearing capacity of the two kinds of joints increased significantly；at the same time，when the stress level of the ball table of the split spherical joint decreased，the stress level of the pressure plate of the ball table increased significantly. The stress level of the ball table and the pressure plate of the ellipsoid joint decreased largely. The finite element analysis showed that the sensitivity of the ultimate bearing capacity of the joint to the wall thickness of the spherical platform was significantly reduced when the wall thickness of the spherical node and the ellipsoid node increased to 7 mm and 9 mm，respectively. © 2023 Hunan University. All rights reserved.