Perforation of aero-engine fan casing by a single rotating blade

To study the mechanism of the aero-engine fan blade/casing impact process, experiments on high-speed spin tester and numerical simulations employing a sufficiently fine mesh and suitable material relations were carried out. Numerical results were in good agreement with the experimental data. The fan casing was perforated under the impact of the blade which was released from the root. The whole impact process can be divided into three stages: the first stage is the released blade scratching the inner wall of the containment area; the second stage is bulge formation and cracking on the casing; and the third is the tearing of the casing along the ribs and the bending of the torn bands. The cracking of the bulge is induced by biaxial tension and the bulge formation is the main energy absorption mode of the casing. In addition, effects of stress initialization on numerical results are assessed according to the interaction force, strain and kinetic energies, and it is found that the stress initialization effects are negligible for this particular problem.