A Model Reconstruction Method of Blade Repair Based on Linear Combination

Repair of damaged blade in aero-engine reduces economic losses and has been applied widely in factory areas. However, the actual blade model after service is not consistent with the theoretical model. Thus, the reconstructed blade model is required. Different damage areas, damage forms and operations in the additive process may lead to different deformations of the blades, thus the actual CAD model of the blade is also different, resulting in the challenge when reconstruct the model. In this paper, a new model reconstruction method of blade-repair is proposed based on the linear combination of base curves blending algorithm. Firstly, the blade after additive processing is measured and such data is processed and registered with the theoretical model. Secondly, the area created by measurement data is smoothly blended to the theoretical area utilizing a developed linear combination algorithm, leading to the capability of providing the reconstructed concave and convex surfaces. Finally, the reconstructed concave and convex surfaces are bridged to theoretical leading and trailing edges. Consequently, the intact reconstructed model of the damaged blade is obtained. The blade-repair case study demonstrates the availability of the proposed method and the analysis of machining error indicates that the blending between the reserved area and the theoretical area of the reconstructed model is smooth.