Numerical analysis and experimental investigation of modalproperties for the gearbox in wind turbine

Wind turbine gearbox （WTG）, which functionsas an accelerator, ensures theof wind turbine systems.performance and service lifeThis paper examines thedistinctive modal properties of WTGs through finiteelement （FE） and experimental modal analyses. Thestudy is performed in two parts. First, a whole systemmodel is developed to investigate the first 10 modalfrequencies and mode shapes of WTG using flexible multi-body modeling techniques. Given the complex structureand operating conditions of WTG, this study applies springelements to the model and quantifies how the beatings andgear pair interactions affect the dynamic characteristics ofWTGs. Second, the FE modal results are validated throughexperimental modal analyses of a 1.5 WM WTG using thefrequency response function method of single pointexcitation and multi-point response. The natural frequen-cies from the FE and experimental modal analyses showfavorable agreement and reveal that the characteristicfrequency of the studied gearbox avoids its eigen-frequency very well.