Study On High Speed Machining Process And Reliability Of Fixture Method For NOMEX Honeycomb

Since the appearance of the honeycomb core composite material, it has been thought highly of by the aerospace industry for a series of merits that traditional material could not possess. Nowadays it is one of the indispensable materials to the development of the aerospace industry. In order to meet the requirements of assembly, connection and others, it is used to carry out a certain milling process after the manufacture of the honeycomb core material. For the reason that the milling parameters mostly based on experience and the present fixture methods being outdated, the machining quality of the honeycomb core part could hardly meet the design requirements. With traditional machining methods, it is usual to get low surface quality and machining precision, even worse, such cases that the honeycomb being pulled up for the shortage of fixture force, over-cut or even out-of-service occurred frequently. In order to solve the problems emerged during the honeycomb machining process, finite element method (FEM) associated with theoretical model building and a series of experiments is employed to investigate honeycomb's fixture methods deeply and extensively, its high speed milling technologies are studied in depth too.In chapter 1, fundamental conception, development and application of composite material are elaborated firstly. Then the characteristics and application of the honeycomb core material are introduced. The great importance of machining this kind of material in the aerospace industry is revealed subsequently. In the end, the factors that affect the surface quality of machined honeycomb core are analyzed.In chapter 2, the high speed milling technological process of a certain kind of honeycomb core that have complex molding surface is introduced, then key technologies and open questions are generalized. Due to fixture technology is one of the key points in the honeycomb machining process, the fixture technology is deeply investigated in this chapter, and the shortcoming of the present fixture methods is also revealed. Correspondingly, a new fixture method based on powerful magnetic field and friction principle is put forward.In chapter 3, a three-dimensional FEM model on NOMEX honeycomb core high speed milling is presented. A series of key technologies relating to the FEM simulation are provided. These technologies involve material property, tool-chip friction, chip separation criterion, energy dissipation and local thermal conduction etc. By means of high speed milling NOMEX honeycomb tests, the FEM model is properly validated and a satisfactory one has been obtained eventually.In chapter 4. by means of milling experiments and NOMEX honeycomb high speed milling three-dimensional FEM simulations, the influence that milling parameters impacting on the milling force and machined surface quality is revealed. Both the quantified surface quality model and the milling force model are set up at the same time. Simultaneously, under the condition of invariable milling efficiency and quality, the...