Research On Digitization Of Manufacturing Technology Of Large Compex And High-precision Skin Parts

The skin part is one of the main parts in the aircraft,which is used in the fuselage,the tail section,the wing,the pressure cabin,the engine room,and other key parts.With the continuing improvement of the performance index of modern aircraft,the shape of the skin parts will become more complex,and the precision of the external dimension and surface quality will be more demanding.At the same time,the new generation of military and civil aircraft are designed with digital design method,and provided in the form of electronic prototype.Besides,the coordination method of "to the digital quantity for manufacturing basis" is the key issue of modern aircraft development.The digital designing,prototyping and testing technology are not only developing with the trend of sheet-metal forming technology,but also meeting the needs of high precision and rapid development.The research is based on the skin-stretch forming equipment,laser engraving machine,five-coordinate skin three-dimensional cutting equipment and the evaluation of existing production ability.It takes bay G280 executive fuselage section of left and right after-skin parts as the research object of digital manufacture,and carry out the research of the digitalization,precision of large complex high-precision skin forming technology.The aim of this research is to obtain a technical solution to the digital manufacturing process of skin parts via simulation optimization analysis,tooling design,manufacturing integration and digital detection technology.At the same time,the digital manufacturing method can reduce the production cost of parts,improve the shape and size accuracy of parts and the digital precision forming technology level of sheet metal parts,which make the manufacturing mode of sheet-metal forming parts transfer from the traditional empirical mode to the scientific manufacturing mode.Besides,it can provide good technology accumulation to the aviation enterprise military and civil aircraft development.Based on the design model of the rear fuselage skin of gulfstream G280,the research provided craft manufacturing model and tooling model,built the finite analysis model based on Pam-Stamp simulation software and analyzed the drawing forming process.The scheme of laser engraving,five-coordinate skin edge-cutting and hole making process were formulated,which were verified by milling test.Besides,this paper investigated the status of digital measurement about the skin part of G280's rear fuselage,which was verified by the measuring tests of skin parts.The simulation results show that when the mold height is up to 700 mm,the elevation angle of the clamp is adjusted to-1.5° and the pressure of the upper mold is increased to 100 kN,the strain distribution during the forming of the skin parts is relatively uniform,and the maximum mold gap is less than 2 mm,which indicates that the rebound situation has been significantly improved.The digital measurement results also demonstrate that the technical route specified in this paper is capable of producing large,complex aircraft skin parts that are both dimensionally and dimensionally qualified.Under this technical route,the manufacturing cycle of parts was shortened from 7 days to 2 days,and the pass rate of one inspection was increased from 0% to 100%,which obviously improved the production efficiency of the G280's skin.The research provides a theoretical basis for the promotion of digital manufacturing technology in the field of aerospace manufacturing and plays a driving role.