Analysis Of Thin-walled Circular Stiffened Steeltubes Subjected To Bending

Wind turbines are becoming an important alternative to standard energy provision.Wind energy is renewable and has no direct pollution related environmental effects,which makes it attractive in many countries. With the development of technique, windenergy technology develops rapidly. The main supporting structure of the wind turbineis assembled by thin-walled circular hollow section (CHS) steel tubes. For wind turbinetower, it is mainly subjected to horizontal wind load and vertical dead load caused bynacelle and rotor. It is found that the bearing capacity of wind turbine towers iscontrolled by bending moment. With the increase of diameter-to-thickness ratio, theload-carrying capacity increases evidently, but results in low ductility under bendingmoment. It is a good way to weld stiffener on CHS steel tubes to improve its stabiliyand ductiliy. At present, most of research is focused on the study of CHS steel tubessubjected to bending moment. And there is little research to study the behavior of CHSsteel tubes with stiffeners. The main contents are as follows:(1) A total of10specimens is fabricated and tested, which includes4CHS steeltubes with stiffeners and6CHS steel tubes without stiffeners. All specimens aresubjected to bending moment. The load, displacement, and strain data of specimens aremeasured in the test. The influence of diameter-to-thickness ratio and stiffeners on thebehavior of CHS steel tubes is analyzed.(2) Three-dimensional finite element model (FEM) is developed using thecommercial finite element software ABAQUS to analyze the CHS steel tubes underlateral load, whose results are validated by the experimental results. In the model, theinfluence of initial geometry deformation and residual stress on the behavior of CHSsteel tubes is considered.(3) A parametric analysis is conducted to investigate the influence of the length-diameter ratio, diameter-to-thickness ratio, layout and dimensions of stiffeners on thestatic behavior of the steel tubes. Based on the experimental research and finite elementanalysis, design suggestions of CHS steel tubes with stiffeners are proposed.