Fracture analysis of a turbine casing

This paper describes the fracture problem of the turbine casing of helicopter engine. Visual inspection of the defected component was incomplete because of the fact that the fracture was repaired by welding during technical inspection of engine. In this work, authors try to explain the reasons of damage of the turbine casing with the help of the numerical stress analysis. In order to solve the problem, a geometrically complicated numerical model was created. The finite element method (FEM) was used in the computations. As a result of nonlinear static analyses performed for both mechanical and thermal load occurring during operating condition, the stress and deformation contours were generated. High thermal stress gradients were found at the region of casing where cracks were detected in engine operation.