Modal shape and frequency identification method for motor stator core with welding groove

The invention discloses a modal shape and frequency identification method for a motor stator core with a welding groove. The method comprises the following steps: establishing an Euler-Bernoulli equivalent beam unit model of a motor stator core with a welding groove, obtaining a total stiffness matrix and a total mass matrix under a local rectangular coordinate system by using a matrix displacement method, and obtaining a structural stiffness matrix and a structural mass matrix under an integral polar coordinate system by using coordinate transformation; and establishing a discrete free vibration model, inputting the structural stiffness matrix and the structural mass matrix into the model, and outputting modal shapes of different orders and corresponding inherent frequencies of the motor stator core, thereby completing identification. According to the method, the process influence of the iron core yoke welding groove is considered, a visual modal shape graph can be obtained, the modal shape and the inherent