Construction Diagnostics of the Aircraft Parts on the Basis of the Energy Method and the Stress-state Stiffness Criterion

Abstract The analysis of the stress-strain state on the basis of equivalent stress and the theories of durability is used for diagnostics of parts at present moment in the typical strength calculations. However a lot of basic aviation parts work at cyclically repeated loadings and they are exposed to loadings and deformation in the field of low and high cycle fatigue. In this case there is necessity of deformation condition calculations or the stress-strain type which significantly influences on the cyclic durability of the parts. For increasing of reliability and cyclic durability of the parts the research purpose is to develop a way and criteria of the analysis and assessment of the stress-strain state for the identification of the most loaded areas of the parts limiting its fatigue. It is offered to consider the stress-strain type on the basis of coefficient of stiffness K S calculated through the main tensions. In this case it is recommended to determine the most subjected to cracking initiating areas of the parts by the largest size of parameter K = K S K U . The research of the finite element analysis of the stress-strain state for the low pressure turbine shaft and high pressure compressor disks of D-30 series gas turbine engine was made according to this parameter. On the basis of this parameter the finite element analysis of the stress-strain state for the low pressure turbine shaft and high pressure compressor disks of the gas-turbine engine of D-30 series is researched in this work.