Deformation and fracture behavior of stator windings subjected to bending loads

This paper presents the deformation and fracture behavior of stator windings subjected to bending loads. A series of bending tests were carried out on four kinds of stator windings, which were composed of steel solid bar or copper strands and mica-splitting tapes, and were impregnated with epoxy and polyester resins. The strain produced on the insulation surface and the deflection of the stator windings were measured, applying uniform bending moment to the stator windings up to failure. The tanδ characteristics were also measured in order to detect the occurrence of mechanical damage produced in the insulation system. A preliminary bending stress and deflection analysis was made and then compared with the experimental results. From these studies, the relationship between the component properties and the composite mechanical behavior of the stator windings is clarified. The failure mechanism of the stator windings is also revealed.