The Digital Machining Technology Of Honeycomb Material Large-scale Irregular Surface

The application of large-scale irregular curved surface made from honeycomb material has become wider and wider in the area of aerospace. It's hard to machine for its typical characteristic of irregularity and low stiffness. In this paper, the fuel isolated layer structure of launch vehicle is taken as the typical component, which separates the liquid Hydrogen from liquid Oxygen. The conventional CNC manufacturing techniques are very difficult to meet the requirements of the precision. In order to solve this problem, Prof. Lu Jiechi in Dalian University of Technology studied a digital machining method for large matching surface, which solved the matching machining of upper-sheet of honeycomb structure. However, it also has some deficiencies, such as unfulfilment of the machining of honeycomb's male surface, low efficiency of the former surface measure method, inaccuracy of the weld feature mining. In response to these deficiencies, based on previous studies, the key technology of digital processing for the large-scale irregular curved surface made from honeycomb material is studied.Based on the manufacture requirements of honeycomb structure and digital matching machining method of "measurement-data processing-path control", under-sheet measurement and matching machining method of honeycomb structure are researched, former machining method and system perfected and updated, and functional reliability of honeycomb structure raised. Also, non-contact measuring method and technique of measuring large-scale irregular surface are studied, with the measuring efficiency promoted, the method of laser measuring path control is researched, error influencing factor of laser measurement analyzed, and scheme of laser measurement designed.Recognition methods of mass data singular area are studied. Drawing lessons from KDD (Knowledge Discovery from Database), with weighted comparative method, a reliable mathematical model of welding feature mining is raised and the mining of that is accurately done.The clamping method and machining technique of large-scale low stiffness honeycomb component are researched. The grinding and clamping mould of honeycomb structure is designed, and the analysis of mould structure reliability conducted by the FEM (Finite Element Method), the scheme of fixing the honeycomb structure in the grinding process is studied, and a pressure pad fixture method proposed, laying the technology foundation for the next transformation of machining equipment.