基于叶型特征重建和缺陷模型提取的LDMD叶片再制造  

LDMD-oriented Blade Remanufacturing Based on CSC Character Reconstruction and Defect Model Extraction

作　　者：王涛[1] 丁华鹏 刘一骝[2] 雷剑波[3] 

机构地区：[1]中国民航大学机械电子工程系,天津300300 [2]挪威科技大学生产与质量工程系 [3]天津工业大学激光技术研究所,天津300387

出　　处：《农业机械学报》2015年第8期333-337,共5页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金民航联合研究基金资助项目(U1333121);天津市应用基础与前沿技术研究计划资助项目(青年项目)(14JCQNJC05000)

摘　　要：为了实现激光直接沉积(LDMD)对破损叶片的再制造,提出了一种利用设计特征重建叶型曲线(CSC)的方法,并提取缺陷3D模型。首先,规划了叶片再制造系统结构;接着,基于叶型曲线设计特征,对前缘(LE)、后缘(TE)、吸力边(SS)和压力边(PS)在叶型点云中的位置进行识别,然后利用圆弧曲线以背离度和拟合误差作为2个阈值,实现对前缘和后缘的拟合,同时实现叶型点云的分割;再利用6次多项式曲线,在保证与前后缘曲线相切的约束条件下,用最小二乘法实现对吸力边和压力边的拟合,从而得到完整的叶型曲线;接着放样叶型曲线得到完好的目标模型,并采用布尔减运算提取了缺陷3D模型;最后,给出了一个叶片再制造应用实例,证明了方法的可行。The blades of gas turbine are usually long-term operated in harsh environments. Due to high temperature and pressure in operation, as well as many external impacts, blades may have various defects, such as erosion, distortion, wear, cracks and impact dents. In order to implement the remanufacturing of defective blade with laser direct material deposit （LDMD）, cross-section curve （CSC） was reconstructed based on design characters and defect 3D model was extracted. First, the remanufacturing system structure of blade was given. Second, on the basis of CSC design characters, the positions of leading edge （ LE）, trailing edge （ TE）, suction side （SS） and pressure side （PS） were identified in cross-section point cloud. In order to obtain LE and TE, the circle curves were utilized to fit the data points with the deviation of point from the circle and fitting error as threshold values. Meanwhile, the cross-section point cloud was segmented. And under the constraint condition of tangency to LE and TE, a sixth degree polynomial function was selected to fit the SS and PS by using the least square method. After some whole CSCs were obtained, the perfect blade airfoil model can be achieved by lofting them. Sequentially, defect 3D model for LDMD was extracted in Boolean subtraction. At last, an application of blade remanufacturing was given, which proved that the method was feasible, and the future research direction was also proposed.

关 键 词：叶片 缺陷模型 激光直接沉积 再制造 

分 类 号：TH166[机械工程—机械制造及自动化] V263[航空宇航科学与技术—航空宇航制造工程]