Mechanical Behavior Research On KT-type Joints Of Lattice Concrete-filled Steel Tubular Wind Turbine Tower

With the large development of Chinese wind power industry, the design and innovation ofwind turbine generator has become an important factor in wind power industry. And it’simportant to study the major supporting structure of wind turbine generator. Compared with thetraditional cone type tower, the lattice tower has a certain advantage in low cost, easyinstallation and maintenance, better low-cycle fatigue character. However, due to the stressstate of the tower is more complicated, especially in the joint. Therefore, the joint structure isthe key course of tower design. Given the current lack of research information and data oflattice wind tower joint, studied the mechanic performance of the KT-type joints of latticeconcrete-filled steel tubular wind turbine generator tower.This paper is related to a research of a1.5MW wind turbine tower as the reference objectwhich located in Inner Mongolia Bayan Obo region. Preliminarily designed a latticeconcrete-filled steel tubular wind turbine generator tower, and had a monotonic static loadingtest of the KT-type joints. Through the changing of the tower diameter-thickness ratio andoverlap rate, the tower joints failure process, deformation relationship of web members, theequivalent stress of the joint intersection and the bearing capacity of the joint characteristicswere analyzed. The experimental results show that the failure modes of joints are the failure ofwebs while there’s no obvious deformation in tower. For lap joints, the high-stress area is inthe gap and on the tower wall between crown point and saddle point of tensile web, and foroverlap joints the high-stress area is on the tower wall between crown point and saddle point oftensile web. The equivalent stress distribution of tension is larger than that of compression.Based on the tests, applied the finite element analysis software, ABAQUS, to discuss theinfluence of some parameters on bearing capacity and failure modes of the joints and toanalyse the test specimens. The results show that: the ultimate bearing capacity of overlap jointwith diameter-thickness ratio18is12.3%larger than that of lap joint, while the ultimatebearing capacity of overlap joint with diameter-thickness ratio14is13.1%larger than that of lap joint. The main effect of concrete is to increase the radical stiffness of joints and the wholetower bending stiffness. The bearing capacity is decreasing with the tower diameter-thicknessincreasing while it’s increasing with the overlap rate increasing. The joint capacity isincreasing with the increase of web-tower stiffness ratio.Through the experimental study and numerical simulation of finite element analysis of theKT-type joints of lattice concrete-filled steel tubular wind turbine generator tower, learned thatthe mechanic behavior and failure mechanism of this type of joints, providing the reference ofjoint design and construction in the future.