An Electromagnetic Loading Method for Centrifugal Load Reconstruction of Rotating Machinery Blades

To statically reproduce the continuously distributed centrifugal load on metallic blades of rotating machinery, an electromagnetic loading method using a non-uniform double-sided linear induction motor is proposed. The method utilizes eddy currents induced in a stationary conductive specimen by a time-varying traveling magnetic field and the resulting Lorentz forces to generate an equivalent distributed load. A mapping relationship is established among the target centrifugal line load, the period-averaged electromagnetic line load, the local wavenumber, and the spatial phase. The non-uniform traveling magnetic field is realized through segmented phase discretization and phase assignment to winding slots. A two-dimensional time-domain finite element model is developed for verification. The normalized spatial profile of the normal magnetic flux density at the specimen midplane has a correlation coefficient of 0.942 with the target profile. Within the main evaluation region, the period-averaged electromagnetic line load reproduces the increasing target distribution with normalized root mean square and mean absolute errors of 12.06% and 9.82%, respectively. The total electromagnetic load over the full specimen length is 8.01% below the target centrifugal load. The proposed method provides a new approach for non-contact static reconstruction of centrifugal loads.