Overview of the application of digital design and

Summary of the application of large aircraft digital design and manufacturing technology

modern large passenger aircraft is a high-tech product of the close combination of advanced jet technology and computer technology. However, the large civil transport aircraft market in the world is dominated by European Airbus and American Boeing, and other countries (such as Russia) are gradually marginalized, especially in the research and development of Airbus A380 and Boeing 787 aircraft. Its competition is very fierce, which fully reflects the country's strategic interests and national will. At the same time, the research and development of A380 and Boeing 787 aircraft has brought the digital technology of large civil transport aircraft to a new level

development of large civil transport aircraft

in the civil aviation transportation industry, large passenger aircraft occupy an absolute dominant position. Large passenger aircraft is also called trunk transport aircraft in civil aviation transportation. It generally refers to large and medium-sized passenger aircraft with a passenger seat of more than 150, a load of more than 30 ~ 50t, and a full load range of more than 3000km. Sometimes, it is called super large passenger aircraft with a passenger seat of more than 400, such as Boeing 747 and Airbus's newly developed A380. According to the range, now it is often called medium/long-range trunk transport aircraft with a full passenger range of more than 6000 ~ 10000km. Most of these aircraft are sailing on international routes, generally wide body airliners with dual channels; Those with a full passenger range of less than 5000km are called medium/short-range trunk transport aircraft. Most of them sail between major cities in China. They are often called domestic trunk aircraft. They are generally narrow body airliners with two engines and one channel, such as Airbus A320 and Boeing 737 series. There is also a smaller regular flight in some areas of the country, from large cities to small and medium-sized cities, with less than 120 passengers. It is called Regional airliners, such as Bombardier CRJ series aircraft, Brazil ERJ series aircraft, China ARJ and Russia SSJ airliners. This kind of airliner is also a one-way regional airliner

complexity of large aircraft development

aircraft manufacturing industry, especially large aircraft manufacturing industry, is different from general machining industry. Due to its high product complexity and great technical difficulty, it is a strategic high-tech industry of a country and a product of high integration of modern science and technology. It is one of the important symbols to measure a country's science and technology, industrial level and comprehensive national strength

the development stage of large civil transport aircraft

large passenger aircraft products are extremely complex, with the characteristics of strict aerodynamic shape requirements, frequent design changes, numerous product configurations, different parts materials and shapes, complex internal structure, compact space, dense layout of various systems, and a large number of components. The Boeing 747 airliner in the United States has up to 6million parts per aircraft, including 3million connectors, wind tunnel blowing for 15000h, and a total cable length of 274km. It has many development stages and long cycle. For example, it took 19 years for Airbus A380 to officially enter the route from the feasibility of the scheme to its delivery. The life of large passenger aircraft is long. For example, the design life of Boeing 777 is 40 years, and it will continue to serve for 20 to 30 years, with a total life of 70 years. The service life of Boeing 737 and 747 aircraft has exceeded 40 years. The development of a large aircraft requires global collaboration. There are thousands of parts suppliers, such as more than 10000 suppliers of A380 aircraft. It is difficult to manage the data in the development process. More importantly, all kinds of equipment required to ensure the safe flight of aircraft, such as software and hardware equipment such as communication, navigation, display and flight control, need to adopt high-tech. At present, there are strict environmental protection requirements, such as less pollution emissions, low noise and high fuel efficiency. Therefore, from the whole development process of the aircraft, that is, from the customer's requirements for the aircraft to the aircraft design, manufacturing, delivery and service after the aircraft is put into service, the aircraft development process is a huge system engineering

application characteristics of digital design and manufacturing technology

in the development of large civil transport aircraft in recent years, whether Airbus A380 or Boeing 787, it fully reflects that digital technology is the core competitiveness of enterprises and the most powerful tool for product innovation and development. Therefore, the application of digital technology has made great progress in both depth and breadth, and its characteristics are reflected in the following five aspects

traditional aircraft development process

1 digital technology has fundamentally changed the product development method

modern aircraft development method, which has evolved from the original serial mode based on physical (physical) prototype to the parallel mode based on digital prototype. Taking Lockheed Martin as an example, the original traditional development process and method can be divided into three stages: conceptual design, preliminary design and production design. In these three design stages, it is necessary to draw mold lines and make physical prototypes to help technicians accurately design the aircraft and configure the internal space of the aircraft. The development process is serial, and the transmission of product definition information is discontinuous. Its shortcomings are well known

in the development of modern new machine, although the development stage of its products has not changed much, its mold line and physical prototype are all replaced by the digital definition or digital prototype of the product, and its development process is parallel, which is convenient to realize multidisciplinary collaborative design

Table 1 Boeing bos-600 series specifications

in addition, its collaboration mode has also developed from the original centralized collaboration based on IPT to network-based distributed collaboration, that is, the product design collaboration team IPTS are no longer concentrated in one place, but distributed around the world, through the network to carry out collaborative design and exchange relevant design information of products. Boeing adopted this most advanced collaborative approach through the global collaborative network environment (GCE) in the design of Boeing 787 aircraft

in the research and development of Boeing 787 airliner, Boeing has not only made great progress in the collaborative way, but also made a major change in the focus of its research and development work. Boeing originally distributed the design information of various parts of aircraft products to suppliers for manufacturing. Boeing supervised the development progress and quality of all products, and finally was responsible for the docking, assembly and test flight delivery of aircraft, that is, Boeing was responsible for the design of all aircraft. However, in the development of Boeing 787 aircraft, Boeing made major changes. It was only responsible for the overall design of the aircraft, and entrusted the extremely heavy workload of detailed design to the component manufacturing unit (Boeing's partner). Finally, Boeing was only responsible for the docking and assembly of more than a dozen large components. Boeing's practice of "grasping both ends" is very scientific. It not only greatly reduces the workload of Boeing company, but more importantly, the detailed design is productive design, which is most suitable for enterprises that know how to manufacture products. This design mode of Boeing also represents the design direction of aircraft products in the future

2 digital technology runs through the whole product development process

Digital Collaborative development is business process centered, with cross regional/multi enterprise, dynamic development characteristics. From the perspective of the overall goal of collaborative development, there are two modes in Product Digital Collaborative Development: horizontal (multidisciplinary collaborative development MDO) and vertical (product life cycle collaboration)

model based ergonomic simulation

on the basis of these two working modes, taking the development process defined by product digitalization as the object, the different enterprises/departments/personnel/information involved in the development in an isolated and discrete state are integrated to work together, and the complete digital product information description required to complete the task is obtained, ensuring the different stages of the development process The parallel work and continuous and effective information between different departments and teams fully reflect that digital technology runs through the whole process of product development. It is a multidisciplinary optimization development mode of aircraft structure design under the condition of digitalization. First, multidisciplinary teams (IPTS) of the disciplines involved in the development must be established. The disciplines involved must have their own effective analysis models and design standards. All models must be parameterized. After digital multidisciplinary optimization, when determining the final design variables, the wind tunnel simulation test results of setting out and aerodynamic shape carried out by geometric shape personnel are combined

from 2004 to 2007, Airbus organized 63 companies from many European countries to participate in the vivace (value improvement through a virtual aeronautical collaborative enterprise) system research project. After a total of four years, it has built a multidisciplinary collaborative development system framework for MDO, and in three aviation fields - helicopters, aircraft and engines, from feasibility study Applied research has been carried out in the whole life cycle from conceptual design to detailed design. In the development process of Airbus A380, the idea of multidisciplinary collaborative development is fully used for aircraft design

Boeing 787 docking assembly simulation based on model definition

digital technology is not only reflected in the design process, but also in the subsequent manufacturing links. Boeing has implemented lean production while implementing digital technology. In this process, in order to facilitate product data management and configuration control, the aircraft product is divided into thousands of modules. During configuration control, the customer's aircraft product is composed of different modules according to effectiveness, and the production process is divided into three simplified operation processes (TBS): tbs1, tbs2 (a, B) and tbs3. According to the nature of the modules, different modules belong to three simplified operation processes. In this way, the data defined by product digitalization can be smoothly transmitted to the production downstream of aircraft manufacturing and assembly plants, and even to the use and maintenance of aircraft

in the development of Boeing 787 aircraft, the physical model, manufacturing model, performance model and maintenance model of the aircraft are also constructed. The collaborative design team has developed from the early DBT (design build team) to IPT (integrated product TAM) and the latest lcpt (live cycle product team). On the other hand, it embodies that digital technology runs through the whole product development process

3 digital definition technology is developing towards MBD (full three-dimensional) technology

because in the usual CAD system, the product digital model established by engineers and technicians is only a three-dimensional geometric model, while the manufacturing process information is still on the two-dimensional drawing

in this way, it is often difficult to produce and inspect products only based on three-dimensional geometric models. In other words, the technicians in the three-dimensional model cannot add the design intent necessary for the production process, mold design and production, component assembly, component and product inspection and other processes in a simple and clear way. Although the three-dimensional model contains the detailed geometric information that the two-dimensional drawing does not have, the three-dimensional model does not include the dimension and tolerance annotation, surface roughness, surface treatment method, heat treatment method, material, combination method, gap setting, connection range, lubricating oil painting range, color, required specifications and standards and other (non geometric) information that cannot be expressed by geometry alone. In addition, in 3D modeling, there are also deficiencies in the means that can more flexibly and reasonably convey the design intent, such as shape based annotation tips, enlarged drawings and sectional drawings of key parts. This leads to the contradiction between using 3D models and 2D drawings in practical engineering. From the perspective of data management, the duality of data sources makes it difficult to maintain data consistency. Based on these serious problems, the American Society of mechanical engineers in Poland in 1997