In the background of that: the new round science and technology revolution and global industry upgrading is expeditiously advancing, the innovation-driven development is erected as state strategy by China and traditional equipment manufacturing industry is under transformation and update, how to realize the transform of the aero-engine assembly from the traditional manufacturing mode characterized by labor-intensified and experience-dominated to the advanced manufacturing mode characterized by digitization, automation and intelligence, increase the assembly accuracy, consistency, reliability and efficiency at upper level, create more and larger value of final manufacturing in the product life cycle, it is not only an important strategic development issue for aero-engine industry, but also a commitment for the ‘pearl on industry crown’ to lead as a model for assembly manufacturing upgradation of other high-tech equipment product. Based on the aero-engine assembly process technology development condition, this paper presents the main gap between China and other country, analyzes the issues wherein, refines the research requirement of fundamental technology and engineering application technology, makes the prospect and suggestion for later assembly technology development. Hopefully, this paper provides the enlightenment and reference for aero-engine assembly process optimization and upgradation, related R & D project planning and establishment.
This paper discusses the key contents and technologies of the assembly process design system based on the assembly digital twin model, aiming at the problem that the single digital model exposed in the implementation of digital assembly technology of aviation mechanical and electrical products cannot fully reflect the features, functions and performance indicators of the products. This paper points out the new requirements of the digitization of assembly process design for product digital model, and expounds the definition and development status of digital twin technology, and discusses the application of digital twin technology in product assembly process modeling. This paper discusses the virtual and real fusion and data exchange of assembling digital twin model and product prototype, and how to use real-time data to aid process decisions and dynamic modification process plan. Finally, the assembly process design can quickly respond to production changes.
As a key stage in the assembly process of large-scale products, pose measurement has characteristics of diverse methods and complex theory. It is helpful to analyze process of pose measurement theoretically by dividing pose measurement modes according to different measurement principles, and studying characteristics of various measurement modes is of great significance for accurate pose measurement. Firstly, pose of component was divided into absolute pose and relative pose according to the assembly process of large-scale products. Secondly, by analyzing principle of relative pose measurement, the research of pose measurement mode was carried out, three basic pose measurement modes were defined, and three combination modes were derived on this basis. Finally, the application of pose measurement mode was analyzed with three specific relative pose measurement cases, which provided a theoretical basis for selection and optimization of pose measurement method in large-scale products assembly tasks.
With the wide application of composite materials in aircraft body structure, one–sided fasteners are also widely used in the assembly process. In view of the problems existing in the assembly process of composite panels and one–sided fasteners, the application status of robotic riveting technology in aviation manufacturing is analyzed, the difficulties of robotic riveting technology for composite panels are expounded, and the key technology research is carried out, then the robot automatic riveting system is designed and developed. The system has the functions of automatic positioning and clamping, measuring, drilling, feeding and fastener riveting of composite panels assembly process, which can greatly improve the assembly quality and efficiency of composite structural parts.
Aiming at the neutral problem of manual electromagnetic riveting, a three-coordinate electromagnetic riveting bracket system based on industrial intelligent camera is designed. The riveting holes are photographed by using industrial intelligent camera, and the center coordinates of the holes are rapidly calculated by image processing, finally the result is converted into the assembly coordinate system according to the coordinate transformation. In this paper, the composition, working principle, hardware and software design of the threecoordinate riveting bracket system are described in detail. Siemens Smart PLC motion control function can achieve three coordinate positioning control, and human-computer interaction interface is established by WinCC touch screen. With the actual implementation process, experimental results verify the effectiveness of the positioning function and alignment accuracy of the system.
Because of composite materials’ excellent mechanical properties, they are widely used in aircraft manufacturing. Due to the large manufacturing deviation, there may be large gaps or interferences in the assembly of composite components. In addition, the brittleness of composite materials is large, and forced assembly may cause local damage between layers. Therefore, compared with metal materials, the assembly process of composites is more complex and the assembly demands are higher. Assembly gaps can be eliminated by measurement and compensation process, but the mechanical properties of shims are different from those of composite materials, and the gap compensation process lacks a unified standard, which may affect the assembly and service properties of composite components. This paper describes and summarizes the worldwide research progress about composites assembly, providing reference for future composites assembly.
The interference bushing hole reinforcement technology can significantly improve the mechanical properties and fatigue performance of the composite structural joint, and the interference size is the key process parameter of the technology. In this study, the resistance of interference bushing installation was analyzed theoretically, and the interference size of TA2 pure titanium interference bushing was taken as the research object. The strengthening resistance, the pore diameter change and the internal damage of the composite were studied by experiments. The results show that the interference size has a remarkable influence on the reinforcement resistance, and the reinforcement resistance increases obviously as the interference size increases. The interference size of the composite laminar hole is uneven along the mounting direction, as well as the amount of interference at the exit of the holes is higher than that at the entrance. When the interference size is 3%, the actual interference size at the exit of the composite laminate hole is as high as 1.5%, and the material damage occurs at the same time, so the interference size should be less than 3%.
As one of the critical steps of application of Automatic drilling and riveting technology, automatic drilling and riveting off-line programming will directly impact the manufacturing period of aircraft panel. This paper analyzed the process of automatic drilling and riveting off-line programming for aircraft panel. Aiming at improving the current situation, a method of fast automatic drilling and riveting off-line programming for aircraft panel is proposed, which has optimized off-line programming process and realizes batch processing for data of off-line programming based on CAA program development technology. It improves the efficiency and quality of automatic drilling and riveting off-line programming of the aircraft panel greatly based on this method.
As a new generation of two–dimensional carbon nanomaterials, graphene has excellent mechanical and electrical properties, and it is an ideal reinforcing material for the preparation of functional composites. Graphene can effectively improve the mechanical properties and electrical conductivity of graphene composites by combining with matrix materials. Polymer–matrix graphene composites can be used to prepare graphene flexible sensors, which has broad application prospects in structure health monitoring for composite material and human wearable devices. The basic properties of polymer–matrix graphene composites are introduced, based on this, the applications of flexible sensors in structure health monitoring and human wearable devices are analyzed. The progress of graphene flexible sensors in monitoring for strain of structure and human physiological motions are reported, and looking forward to the future developments of graphene flexible sensor.
Fireproof property is a key performance index to measure the safety of aero-engine titanium fire, which is generally evaluated by the abilities of titanium alloy materials/components to resist thermal spontaneous combustion, ignition and extended combustion. Aiming at the demand of advanced high-temperature titanium alloys for highperformance aero-engines, this paper reviews recent experimental studies on ignition resistance and combustion resistance and introduces the research progress of non-isothermal oxidation behavior and fireproof mechanism of fireproof titanium alloys, high temperature titanium alloys and intermetallic titanium aluminides from the aspect of thermal spontaneous combustion resistance. Finally, the future direction of development is prospected.
Aluminium alloys have been widely used in aeronautical engineering due to the advantages of high strength and easy processing. Low temperature is an inevitable environmental factor in using of aluminium alloys, and the cryogenic fatigue of aeronautic aluminium alloys has been greatly concerned by the engineering and academics overseas and domestically. The experiment researches on cryogenic fatigue of aeronautic aluminium alloys in recent years were generally reviewed here, meanwhile, the cryogenic fatigue failure mechanisms were analyzed. After that, the characterization model and life evaluation methodology on cryogenic fatigue of aeronautic aluminium alloys were summarized, and further research problems in experiment, failure mechanism, characterization model and life prediction were pointed out, which provides a technical support for engineering design and application of aeronautic aluminium alloys.
