Strength Assessment of the Gas Turbine Engine Fan Disk Based on Its Fracture Toughness Analysis

Abstract

The competitiveness and economic efficiency of aviation gas turbine engines (GTE) are determined by the level of their reliability and resource. One of the most stressed elements of the GTE are disks. It is known that their destruction can lead to an air crash, and structural, technological, operational and other factors can be the cause of this. The specified level of reliability must be ensured throughout the entire engine operation. The evaluation of the crack resistance of the GTE fan disk using an improved method for calculating the development of cracks in structures under cyclic loading, which is based on determining the magnitude of elastic-plastic deformations by the finite element method in the area of the crack tip, is given in the paper. The study was performed for two options of the calculation scheme. In the first one, the disk is considered taking into account the interlocking joints of the blade shanks, which are in contact with the disk teeth. They are modeled by a layer with orthotropic material properties. For the second option of the calculation scheme, the interlocking joints were not included in the model, and the load was applied to the disk rim. In this case, the centrifugal force load from the interlocking joint was taken into account. It was established that the hub of the disk is more stressed than the rim. The nature of the destruction of the GTE disk from the hub and rim sides is different, which is explained by the change in circumferential stresses in the direction of the crack depth. The crack displacement during the destruction of the disk in the rim occurs in the radial direction, and in the hub – in the axial direction. The results of the conducted research will increase the period of reliable operation of aircrafts, reduce the costs and time of their development, and will also contribute to increasing safety in performing civil and combat missions.