Aspects of simulating stable low-cycle fatigue crack growth in the main parts of aircraft gas turbine engines

Abstract

The article presents theoretical basis for the industry-based approach for finite element modeling of stable crack growth in the main parts of an aviation gas turbine engine. An axial compressor disc is used as an example. Parameters of typical FE-models applied are provided. In addition, some effective practices of FE-modeling representing the novelty of this work are described: crack evolution increment under-relaxation and automation of the process of constructing a new crack front. Some simulation results are presented demonstrating implementation of the approach steps and benefits gained from the application of the listed features. Under-relaxation ensures maintaining the stability of a numerical solution for a significantly larger crack increment size. This leads to essential effort decrease as a result of reducing the total number of simulation cycles required. Automatic construction of a new crack front allows significant improvement in crack representation accuracy during the simulation process due to the greater number of points for which crack front evolution is determined.