A methodology for computing bending and torsion deformation ofceramic cores based on convexhull algorithm

Bending and torsion deformation of ceramic core have a direct impact on the wall thickness accuracy of hollow turbine blade. To overcome the difficulties for determining deformation by extracting or fitting contour lines based on 3D registration of measured point sets and CAD model such as the slow convergence and low efficiency, the bending and torsion degree of ceramic core was proposed and a new algorithm for ceramic core bending degree and torsion degree was studied through the geometric characteristics of ceramic core measurement data based on convexhull algorithm and distanceweighted method. Through corresponding verification experiments the accuracy of proposed method was proved. The results indicated that the accuracy of the calculated torsional and bending deformation was 99.55% and 99.98%, respectively; compared with the twodimensional registration method, the deviation of the torsional and bending deformation was only ±0.01mm and ±0.006°, respectively.