Finite element analysis of shafts with lands and holes under torque loading using cyclic symmetry

The development of aeroengines with increasing thrust capabilities requires the development of shaft technology to deal with this greater power transmission, while still restricting their dimensions and weight. One important way of achieving this is by reducing the core size of the engine. The diameter of a low-pressure driveshaft is one of the main factors determining the overall size of the core. A key design objective is to reduce the diameter while at leat maintaining the same torque capacity. This requires the optimization of the geometry of individual stress-raising features. This paper focuses on one of these, the holes that allow the transfer of sealing and cooling air around the engine. A series of parametric studies is presented, which show the interactions between the holes, the reinforcement lands, and the adjacent plain shaft sections under torque loading. These use a cyclic symmetry-based modelling approach to reduce computational expense. Guidelines are proposed for selecting the thickness and axial length of the lands.