Repair of defective 3D blade model based on deformation of adjacent non-defective cross-sectional curve

Currently, most blade repairing methods are primarily oriented for a straight or slightly curved blade; moreover, they are based on non-contact measured point-cloud, resulting in low accuracy and significant uncertainty-related issues on the defective region during repair. Therefore, this study investigates a contact measured point method with a high accuracy to analyze the repairing of a defective twisted blade; in addition, the paper proposes a new repairing method of deforming the reference cross-sectional curves adjacent to defective cross-sectional curves recursively. In order to accomplish the aforementioned, first, an interpolation algorithm of the cross-sectional curves using B-spline is set; thereafter, a criterion of the measured point density based on the size relationship between the defective region and the blade as a whole is determined. Subsequently, the registration algorithm of the reference curve and measured points of the defective cross-sectional curve to facilitate the deforming operation is provided. An iteratively moving distribution algorithm of all control points belonging to the reference curve is proposed by this paper in order to realize curve deformation. The paper presents twisted blade repairing examples and also compares the repairing surface and the designed surface to verify the validity of the proposed method. The blade repairing method proposed in this paper is aimed to guarantee a surface smooth restoration with higher accuracy and offers good conditions for several designing and repairing cases.