Study On Structure Analysis Technology For Wind Turbine Main Shaft Based On Nonlinear Contact Analysis

Main shaft is the main driving part and bearing part of the wind turbine, it connectsthe blade and gear box, and suffered all kinds of complicated loads from wind turbines.The performance of main shaft directly affects the safety and reliability of the windgenerating set. As a result, the studies on static and dynamic analysis for the main shafthave high practical significance. In this paper, a certain type of MW level wind turbinewas taken as the research object. With using the finite element analysis method andtheoretical calculation, based on the nonlinear contact theory, the static strength wasstudied deeply. And fatigue life was checked by using multiaxial fatigue theorys, andthe influences of the bearing for the main shaft modal are discussed. The analysis resultsprovide reference and basis for the structure design and dynamic characteristics study ofwind turbine main shaft, and have some engineering practical value.The main research contents of this paper are as follows:①Based on the structural characteristics of the main shaft, the shaft geometrymodel was simplified. By using the finite element software Hypermesh is used to meshmodel of the static strength finite element analysis model of the main shaft.②The nonlinear static strength of main shaft was analyzed. For Simulation ofroller bearings, two finite element models of static strength analysis were constructed,roller simulated by deformable element and gap element. The optimal solution would begot based on the comparison of analysis results.③Multiaxial fatigue life of main shaft was analyzed. Based on the Miner’s rule,fatigue analysis was constructed. S-N curve and time history was discussed. Fatiguedamage of main shaft was calculated by using multiaxial fatigue method to check thefatigue life of main shaft under fatigue load.④Modal analysis for main shaft. Considering the elastic support of bearing andfully controlled bearing, two models of modal analysis were constructed. By comparingthe analysis results, the impact of elastic support of bearings on the natural frequency ofmain shaft was researched.