A TEMPLATE BASED HOLLOW TURBINE BLADE WALL THICKNESS INSPECTION METHOD USING ITS CONE BEAM CT IMAGES AND CAD MODEL

摘要

Hollow turbine blade wall thickness is a critical parameter for ensuring its strength. A template based wall thickness inspection method by using its Cone Beam CT images and CAD model was presented in this paper. Firstly, a modified Marching Cube algorithm was used to generate the blade geometric boundary mesh model from its CBCT images. Then, align the mesh model and the CAD model through the rough alignment method and the Iterative Closest Point based fine alignment method to bring these two models into one common coordinate system. After extracting a wall thickness inspection template from the CAD model and performing the intersecting calculation with the blade mesh model, the wall thickness deviation on the certain section could be generated automatically. The related algorithms was implemented with VC++ programming and verified by a set of simulated blade CBCT images.