Equivalent and simplification of nickel-based single crystal plates with film cooling holes

Abstract

The mechanical properties of orthotropic material thin-walled plate with close-packed film cooling holes were studied based on the equivalent solid material concept. The equivalent principals of plane stress conditions, plane strain conditions, generalized plane strain conditions and general stress conditions were considered. A simplification method for square and triangular penetration patterns was presented. Extensive numerical simulation results covering different ligament efficiencies, penetration patterns and stress conditions were provided for the directionally solidified superalloy and nickel-based single crystal superalloy to verify the feasibility of equivalent principals and simplification method. Three crystal orientations [001], [011] and [111] of nickel-based single crystal superalloy were analyzed. The stress concentration factors were obtained for the mechanical behavior analysis of cooled blade. The values of equivalent error are all less than 10% when the ligament efficiency is larger than 0.4. The tensile deformation, Mises equivalent stress and stress distribution under the same stress level show the crystal orientation correlation. The tensile deformation of three crystal orientations is: [001] > [011] > [111]. The maximum Mises equivalent stress of [001] orientation and [011] orientation around the film cooling hole are basically the same, and they are all less than [111] orientation. The maximum and minimum values of stress concentration factors are 3.49 and 1.82 respectively.