The application of multi-point dies in the aluminum alloy integral panel forming is a novel forming method. However, how to predict and avoid the instability and fracture of the stiffeners has become a difficult problem in practical application. In this paper, the criterions for instability and fracture of the stiffeners in multi-point forming process were proposed. And the finite element simulation and multi-point bending test were carried out to make a comparison. The results show that the criterions proposed can predict the positions and moments when the instability or fracture occurs. Moreover, the changing of fracture and instability with different bending radius in step-by-step multi-point forming was investigated, and the forming limits of the stiffeners were also found out. The instability and fracture of integral panels with varying path forming were simulated, and the optimal loading path is selected.

      Digital twin, as the key technology of cyber-physical system, can digitally describe the physical world and effectively manage and control the data of the entire product lifecycle, and provide new ideas to optimize the various activities in product research and development. The concept and research progress of digital twin is discussed, aiming at the two problems existing in the current CAPP (Computer Aided Process Planning) research, the concept of as-build model is introduced, the design framework of CAPP under the digital twin is proposed, and finally a real-time process decision-making method based on digital twin and a process knowledge mining method based on digital twin are discussed.

      In order to fabricate a type of titanium hollow structure, a new process is developed based on hot isostatic pressing (HIP). The hollow ring structure is first decomposed into the skin plus ribs structure, then these substructures are combined together with adding a internal package into the hollow space. After HIP process, rectangular, cylindrical and conical hollow structures are fabricated, under 800-900℃ /100-200MPa/1-3h. The quality of this part is analyzed through profile examination, interface microstructure analysis and mechanical performance test. The results show that the interfacial diffusion bonding ratio of hollow structures almost reaches 100%, and the highest bonding strength reaches more than 980MPa, which is equal to the base metal. The fracture profile of diffusion bonding interface tensile samples shows ductile properties, and the feasibility of this new process is verified, which will provide reference for aerospace applications.

      Aiming at the demands for high precision forming of continuously multi-bent tube in space, this paper reviews the developments of simulation technologies at domestic and abroad. This work proposes simulation process knowledge for tube based on knowledge-engineering. A geometric motion simulation system about tube is established by parametric driving. The extraction of model data, selection of process parameters, creating simulation models, bending process simulation, simulation of springback process, generation of simulation reports and NC code can be automatically realized by applying this system in the continuously multi-bent tube of aircraft. This simulation system can reduce working intensity of technicians and improve work efficiency at process planning in tube of aircraft.

      This paper has studied how material properties fluctuation effects on bending spring back of the high strength steel, through uniaxial tensile tests by sampling based on the orthogonal test, and found out the material mechanical properties have great fluctuation by analyzing the uniaxial tensile test data. Then FE model is established according to working condition of the actual bending machine, and the model is proved to be accurate by comparing the simulated result with the bending experimental result. At last all the uniaxial tensile data are input into the FE model respectively and the result shows that the fluctuation of the material properties has a great influence on the bending springback of the high strength steel, among which the influence of material thickness on the bending springback has reached to 2.12° and material orientation to 0.21°.

      The advantages of shear tests for identification of the flow curve of metallic material were described by comparing the other test methods, for example, uniaxial tension/compression test. The research on metallic material shear tests was reviewed in this paper, in which the tests were divided into two kinds of shear tests according to the stress state of deformation zone during testing, i.e. shear test under simple stress state and shear test under complex stress state result from other loading methods. All kinds of devices and typical geometries of specimens were introduced and the loading methods of shear tests were described in this paper. The applications of all kinds of shear test were summarized according to the advantages and disadvantages of shear test method.

      With the rapid development of our country’s aerospace industry, precision sheet metal parts are more increasingly used. According to different design and application requirements, aviation pipe parts have also been improved from the original free bulging process to various controllable bulging processes, which have greatly broaden the application range. One of the metal molding processes is internal high pressure bulging process, which is widely applied in aviation manufacturing fields. The difficulty form, multiple influencing factors and the complex process are always hard to resolve. In this study, an example of the aviation clamp part is investigated. Axial material compensation amounts, internal pressure and loading paths have been discussed. Through the numerical simulation analysis, the process parameters can be optimized, a simple high-pressure tube bulging process method has been successfully applied, which is beneficial to shorten production cycle and save production costs.

      With the development of intelligent manufacturing industry, the function of tool management system is steadily broadened for diversified demands of customers. Aiming at taking the entire chain of cutting tool after process design, which incorporates selection, purchasing, usage and scrape, into consideration, this paper presents an intelligent manufacturing tool management system (IMTMS) for cutting tool-flow monitoring, and achieves of advantages of digitization, networking, intelligence and visualization for whole life-cycle management of cutting tool. In view of the complexity and low reliability of current available tool condition monitoring technologies, an indirect tool residual life prediction methodology is proposed based on the surface roughness of the workpiece in engineering applications. The IMTMS has been demonstrated of good performance by insitu tests.

      The skeleton layout design of assembly jig needs to consider the constraint relationship with assembly products and locators or clamps. Therefore, the design process is complicated and difficult to achieve optimal design. In order to improve the design efficiency and design quality of the skeleton, an optimal layout design method for aircraft assembly jig skeleton based on least square is proposed in this paper. Firstly, the optimal mathematical model of skeleton optimization layout is established based on least square method; then the optimal solution algorithm of the model is established under the different positioning feature distribution situation of assembly products; finally, the optimal layout algorithm of the skeleton is realized based on CATIA system and CAA technology, the effectiveness of this algorithm is verified by the aircraft wing and front fuselage products. The algorithm makes the skeleton layout design simpler and faster, and also be the optimal design result, which can effectively shorten the design cycle and greatly improve the design quality.

      The mechanical properties of thermoplastic composites depends on the thermal history during processing. So it is important to determine the temperature distribution in the composite during the thermoplastic filament winding process. A mathematical model about thermal conduction in the thermoplastic filament winding process was established. The finite element analysis software ANSYS was used to simulate the thermal conduction. Temperature distribution plots are gotten. Furthermore, the change status of layers is analyzed. The measurement system of the layers temperature field during the winding process was established, and the correctness of the finite element simulation is verified.

      The sole data source of product is defined by 3D annotating technology, which contains all technical information of product and is a substitute for 2D drawing. Firstly, to solve the problems such as low efficiency and heavy workload of annotation inspection, the rationality of annotation is expounded and the common annotation issues are concluded. Secondly, after analyzing common annotation problems, an annotation element model (AEM) is proposed and the rules of annotation inspection are summarized, then establishing the datum and geometric element of AEM, whereas the annotations are checked term by term according to the criterions, and the reasonability of the relationships between the tolerance values on the same geometric element is measured consequently. Finally, based on CATIA system, automatic inspection function of geometric tolerance annotation is developed, which improves the annotation inspection efficiency.

      In the process of material distribution in aircraft component assembly shops, there are often cases of early feeding and passive picking, which can easily lead to large inventory pressures, lagging production information, and slow material delivery response. With the continuous development of information technology and internet of things technology, MES, ERP, PLM, RFID, bar code and other technologies have been used in aircraft assembly workshops to generate a large amount of real-time information, which is in order to achieve the correct distribution of materials in the aircraft department loading shop. It is possible to deliver the correct time to the correct production station. This paper analyzes the characteristics of the aircraft parts assembly materials distribution process, establishes the material distribution framework of the aircraft parts assembly shop based on real-time information, explains the material distribution operation process of the aircraft parts assembly shop based on real-time information, and designs the aircraft component assembly shop material distribution system. The feasibility and effectiveness of the framework is verified by an example of a fuselage assemble shop in an aircraft.