关键词: 涡扇叶片, 非均匀有理B样条, 曲面建模, 弯矩理论, 自适应采样

Abstract: The machining and measurement accuracy of the blades directly affect structural strength and aerodynamic performance of the turbofan.To improve the sampling accuracy and efficiency of on-machine measurement for blade quality inspection,a curved surface sampling method based on bending moment theory was proposed to solve the problems of sharp curvature change at leading edge or trailing edge and global profile sampling.According to the geometric characteristics change trend of blade surface,the arrangement of sampling points was confirmed automatically.The effectiveness and feasibility of the proposed method was verified by case simulations and on-machine measurement experiments.In contrast to the bidirectional isoparametric method,improved partition isoparametric method and Hammersley sequence method,the results showed that the proposed method realized the fine and accurate adjustment of the position and number of sampling points.It had the excellent performance of tiny sampling error and high surface reconstruction accuracy,which could well meet the requirements of on-machine measurement on time and accuracy.

Key words: turbofan blade, non-uniform rational B-spline, surface modeling, bending moment theory, adaptive sampling