Development Of Surface Reconstruction System For Repair Of Twisted Turbine Blades

Repairing worn turbine blade is a hot topic of remanufacturing engineering. There have done a lot of research in this area by domestic and foreign scholars. But they are mostly concentrated on repairing the straight blade. There have not effective method for repairing twisted blade. Turbine blades often have defects such as wear and tear during use, and makes the original CAD surface model is no longer suitable for the purpose of processing precision repair. Direct this difficulty of twisted blade repair, in this paper, a twisted turbine blade surface restructuring algorithm is considered. Including research the error calculation algorithm, IGES file format output, surface reconstruction system development. The main research works of the dissertation are as follows:1) This paper investigated current research state of repair turbine blade surface, analyzed the key technical problems existed in this area, and proposed a repair strategy for free-form worn turbine blade components surface.2) Analyze the curve fitting algorithm, such as approach method, free-form curve fitting method and so on. Compare these algorithm’s advantage and disadvantage. Find the suitable method fitting the turbine blade surface. Research the method of reverse control point, preparation for the optimization of surface fitting.3) Solving the problem that the each layers initial measured point’s number is not equal. Then compute the control points of the surface, using Non-uniform B-spline method to get the twisted turbine blade surface model, and output the model by IGES standard. Import the IGES file into UG and verify that the file is correct.4) Base on the origin blade model and fitting surface model, research the method of how to calculate the error of reconstruction surface. Get the precise error, and proof the algorithm is suitable and right.5) On the basis of the above mentioned study, and through Visual studio2008software, and OpenGL3D graphics technology, a prototype system was developed to identify and repair the surface of the worn turbine blade, and the feasibility and stability of system was verified through examples of blade models.