Abstract: Because of complicated structure and load condition, accurate rigidity/strength analysis of the runner hub is difficult to the axial flow water turbine. To study the stress and displacement distribution of the axial flow runner hub in operation, the rigid-ity/strength analysis is conducted by using FEM based on dynamic equations of elastic structure and periodic boundary condition. One sector including whole pintle hole is selected as computation model. Two operation points including rating poi- nts, maximum head points and two running away points are taken into account. According to the result, the maximal stress of the hub on the running away point is larger far and away than that on the normal points. The maximal stress and distortion lie the lower part of the big pintle hole, which accord with the fact. And the result shows that the method used is effective.

Key words: FEM, Rigidity/strength, Runner hub