一种受损叶片数字化3D模型重建方法研究

3D Digitalized Model Reconstruction of Damaged Blades

航空发动机叶片长期工作在高温、高压的恶劣环境下,经常会出现各种各样的损伤。对受损叶片进行修复,是目前比较经济的做法。受损叶片三维模型逆向重建是叶片修复的关键技术之一,针对此技术,提出一种面向损坏叶片的不依赖于叶片原始模型的数字化3D模型逆向重建方法。首先,对扫描获得的受损叶片点云进行预处理。其次,对不同损坏部位的叶片分别进行逆向建模,对于叶尖受损的叶片,提出一种灰色GM(1,1)叶型重构算法,重建其叶尖受损部位的叶型,提高叶型放样建模的准确性;对于叶中受损的叶片,只需提取未受损部位叶型,放样获得叶片的完整模型,如此,在保证建模精度要求的前提下,减少计算量,提高叶片的建模效率。最后,对叶片重建模型进行误差分析和流场分析,验证建模方法的可行性。结果表明,重建模型的精度可以达到叶片维修要求。

A ero-engine blades are long-term operated in harsh environments. Because of high temperature and pressure, as well as foreign object impacts, blades may have various defects. 3D model reconstruction of damaged blades is one of the key technologies of blade repairing. A method is put forward to reconstruct the 3D digital model of blade, which does not need original design model of the blade. Firstly, to acquire and process the point cloud of broken blades. Secondly, respectively to reconstruct the digital model of blades which are damaged in different parts. For tip damaged blades, based on GM（1,1） cross section curve （CSC） reconstruction algorithm, the 3D digital model of blade is reconstructed The precision of model is improved by reconstructing the CSC of blade tip. For middle part damaged blades, only need to construct the CSC in undamaged part, and then loft the CSCs to reconstruct the 3D digital models. In this way, the calculation amount is reduced and the modeling efficiency is improved with a satisfactory precision accuracy. Finally, to check the precision of the 3D digital model and perform an error analysis. The results turn out that the proposed 3D digital model can meet the technical requirements prescribed in the aircraft engine maintenance manual.