Precision forging blade of aero-engine is a typical thin-walled part with complex curved surface. In order to improve the assembly accuracy of tenon fixture, a multi-point flexible fixture design method is proposed. Combined with the designed fixture structure, the assembly accuracy is evaluated and optimized. Firstly, based on the six-point positioning principle, the influence of milling force on the deformation of parts under different clamping positions was investigated, and then clamping position and clamping mode of the blades were optimized. Secondly, a coordinate measuring machine is used to test the assembly accuracy, revealing poor contact between the blade and blade basin positioning pillars/air inlet edge positioning pillars, with a maximum planar error of 0.0353 mm. Finally, an integrated processing strategy is implemented to optimize the assembly process of the tooling fixture. According to the test results of fixture assembly accuracy, when using the optimized tooling fixture process, assembly accuracy for the three adjacent planes of the blade tenon is ±0.0049 mm, ±0.0063 mm and ±0.0063 mm, meeting the processing requirements for the blade tenon.

With the emergence and development of meta-structures, many phenomena in the field of mechanics that are difficult to realize with conventional materials or structures are gradually becoming possible. Fibre reinforced composites have excellent mechanical properties and can meet the requirements of light weight and high strength. Combining the performance advantages of advanced fiber composites and the unconventional behavior of auxetic metastructures, a negative Poisson’s ratio meta-structure (also called auxetic meta-structure) was prepared by hot pressing molding through a combination mould based on carbon fiber reinforced epoxy resin composite and the classical re-entrant configuration. Subsequently, studies on deformation, failure, buffering and energy absorption of the auxetic meta-structures were carried out by quasi-static and dynamic impact experiments, and the corresponding finite element analyses were also performed. The results show that the meta-structures have different load-bearing capacities, failure modes and auxetic effects in different characteristic directions (including re-entrant direction #1, vertical to the re-entrant direction #2 and outof-plane normal direction #3). Specifically, there is an auxetic effect when the impact is in the #2 direction and the failure mode is wrinkle fracture, whereas when the impact is in the #3 direction, there is no progressive failure but rather buckling separation from the bond interface. The failure modes of auxetic meta-structures have been shifted compared to the quasistatic case, therefore, impact energy absorption, specific energy absorption and auxetic effect are weakened. In the future, triggering methods and filler materials can be further developed to improve the buffering and energy absorption of the auxetic meta-structures, so that they can be applied in the field of impact protection engineering.

With the growing demand of large-scale aerospace equipment, efficient and high-precision large-scale topology optimization design becomes focal point in this field. To address the issues of massive computational load and low efficiency in existing large-scale topology optimization design, study of full-process accelerating design of topology optimization based on GPU parallel computation is carried out. The proposed method accelerates the entire process including meshing, stiffness matrix computation and assembly, and solving of finite element linear systems, achieving efficient and precise voxel meshing and high-efficiency solutions to finite element process. Moreover, the proposed method parallel accelerates the sensitivity filtering process aiming at the accelerating demand by the topology-optimization design process. The design case of a 3-million-voxel attitude thruster model demonstrates that compared with the parallel speed-up ratio of topology optimization by the Abaqus 2022 software, that of the proposed method increased 1259%, and the similarities of the two methods are extremely high, verifying the validity and practicality of the proposed method.

The rotor engine is of uneven temperature distribution inside the cylinder block during its working process, which would cause thermal stress, thermal fatigue and other problems, affecting service life of the engine. To improve safety of the rotor engine during operation, extend its service life and address the main issue of high temperature in the high-temperature region, three optimization methods including lengthening fins, grid structure, and copper–aluminum integration are proposed based on the theory of heat transfer of the rotor engine. Based on the premise of verifying the simulation correctness, the heat exchange processes of different models are simulated using Fluent. The simulation results show that the proposed three schemes can improve heat dissipation performance of the rotor engine. Compared with the unoptimized model, surface area of the lengthened-fin model increased by 124.4%, heat dissipation capacity increased by 4.9%, these of the grid-structure model increased by 158.5% and 8.3%, respectively. As for the copper–aluminum integration model, with the synergistic effect of structure and material, has an increase of 15.2% in the heat dissipation capacity. The experiment demonstrates that rational optimization of fin structure and material can improve heat dissipation capability of the rotor engine.

Interlayer hybrid composites are composed of a variety of fibers and matrix, which enables the full play of advantages of various composites and realizes the coordination of various properties. However, complexity of the manufacturing process and uncertainty of the parameters make it difficult to optimize the design of interlayer hybrid composites. In order to solve the above issue, based on the multi-scale uncertainty propagation analysis method, this paper realizes the propagation analysis and accurate measurement of the macro-parameter uncertainty through the neural network model, and defines the multi-scale uncertainty propagation law of interlayer hybrid composites. In the case of considering uncertainty of the macro material properties, multi-objective optimization algorithm is used. The co-optimized design of buckling stability of the stiffened panel and structural lightweight is carried out, resulting in maximized critical buckling load and reduced mass of the stiffened panel.

Aerospace equipment is evolving towards greater mobility, extended range, and increased load-bearing capacity, which puts forward higher requirements for the lightweight design of structures. As the new type of low-density lightweight structure, lattice structures have excellent mechanical properties such as high specific strength and specific stiffness, showing great prospects in the field of lightweight design. However, the lattice structures generated by traditional array method is not being able to avoid damage to integrity of the lattice structures and stress concentration due to the cropping operation, particularly in modeling structures with complex shapes. This study proposes a unified mathematical characterization and conformal design method for lattice structures based on implicit modeling. The design of functional gradient conformal lattice structures is achieved through the size-optimization technique. Design experiments of fairing and skin demonstrated that gradient design of conformal lattice structures enhanced structural stiffness. Stiffness of the optimized fairing and skin increased by 23.0% and 60.5%, respectively, which verifies potential of the proposed method in application of lightweight design of aircraft structures.

The angle milling head, a specialized tool capable of expanding machining range and improving adaptability of machine tools, is extensively applied in the machining of complex aircraft structural components. However, its high length/diameter ratio often leads to low rigidity, making it highly susceptible to chatter during actual machining processes, which severely impacts machining efficiency and accuracy. A two-degree-of-freedom (two-DOF) tuned mass damper (TMD), externally mounted on the angle milling head with minimized structural modifications, is specifically designed for suppressing vibration of the angle milling head along two orthogonal axes and milling chatter. Based on experimental measurements of the angle milling head’s dynamics, a dynamic model for the angle milling head–TMD system is developed. Numerical optimization is then carried out to determine the optimal dynamic parameters for the TMD. A configuration design for the two-DOF TMD is performed using the graphical approach according to mode shapes of the angle milling head, followed by finite element simulations of the TMD prototype. Finally, modal tests and cutting experiments were conducted to validate effectiveness of the TMD. Experimental results demonstrate that after installation of the TMD, the maximum magnitude of the frequency response function measured at the end of the angle milling head decreased by 73.5%, while the stable cutting depth increased by 300% (from 0.4 mm to 1.6 mm at spindle speed of 1000 r/min).

In order to be applicable to high-efficiency coating of large-format materials, a cold cathode electron gun with wide-rectangle beam spot was designed, the key parameters were simulated, effect of the cathode and anode key parameters on electron beam quality were analyzed, and the optimal dimensions of key components of the electron gun were obtained. Key parameters of the developed electron gun were verified on a morphology testing platform of widerectangle beam spot, the actual test results show that focal length of the electron gun is 200 mm, current density reaches 10.3 A/m², beam spot length is 650 mm, width is 15 mm, and the designed structure meets the requirements of the widerectangle beam spot emission.

Aiming at the requirement of high precision and fast fitting of surface features of parts in high-fidelity virtual assembly of head-up display (HUD) devices of automobiles and aircraft, a blue-ray random point cloud processing and fitting method is proposed. Firstly, the K-nearest neighbor point cloud combination filtering method is used to remove noise points and redundant points. Secondly, the internal surface of the filtered point cloud is quickly fitted based on the fast base surface construction and iterative optimization fitting method of non-uniform rational B-splines (NURBS). Finally, the point cloud boundary extraction and surface cutting are carried out based on the rolling ball algorithm to obtain high-precision surface features which could accurately reflect the point cloud boundary information. A complete set of HUD system standard parts was designed and processed, and the blue-ray point cloud of the main mirror was obtained to carry out fitting accuracy and efficiency evaluation experiments. By comparing the fitting surfaces of the proposed method, commercial software method and literature method with the surface data obtained by three coordinates accordingly, it can be concluded that the proposed method can achieve micron fitting accuracy on the premise of significantly improved fitting efficiency, and can meet the technical requirements of high-fidelity virtual assembly.

Aiming at the vibration problem of aircraft skin during the thinning process, the vibration suppression technology for mirror milling of thin-walled parts based on magnetic follow-up support fixture is proposed. Firstly, the frequency response functions and vibration amplitudes of workpiece under different milling conditions are compared and analyzed by using finite element analysis software, principle of the mirror milling vibration suppression technology is determined. On this basis, a new type of magnetic follow-up support fixture is designed. The mathematical model of axial magnetic force considering pitching angle of the fixture is then established to ensure application of the fixture more effectively; dynamic response at the milling point when the balls are not in contact with workpiece is investigated specifically and the optimal support air pressure is determined. Finally, the fixture was manufactured and experiments of aircraft skin milling under different machining parameters were carried out. The experimental results show that when the fixture clamps workpiece with applied support air pressure of 0.1 MPa at the same time, the vibration amplitude of workpiece is significantly reduced, which proves effectiveness of the proposed vibration suppression technology.

Silicon nitride (Si3N4) ceramics are ideal materials for turbine blades, thermal protection systems and aerospace structural components due to their high-temperature resistance, wear resistance, high strength and excellent thermal shock resistance. However, with the development of aerospace structural components towards higher service temperature and lightweight, shortcomings of Si3N4 ceramics in terms of molding and performance gradually appears. In addition, the existing performance tests mostly focus on working conditions of normal temperature, normal pressure, and transient state, which are not being able to reflect the real service performance of Si3N4 ceramics in aerospace field, therefore need to be improved urgently. To address these problems, this paper elaborates the research progress of Si3N4 ceramics in the aspects of molding, performance testing, microstructure control and mechanical properties, discusses the current status of Si3N4 ceramic application and puts forward relevant suggestions to promote innovation and development of Si3N4 ceramics in aerospace.

High-precision measurement data is the key to digital preassembly analysis. In order to solve the problems of complex measurement planning for various departments, various forms of measurement data without traceability, low data management and sharing degree, etc. during the assembly process of aircraft components, the model construction and data management methods for 3D measurement in aircraft manufacturing process are presented. The 3D measurement model is constructed by integrating the measurement features, measurement benchmark, feature dispersion, measurement methods and deviation analysis in the measurement planning. The data management system is used to achieve structural and unified management, so as to conduct the measurement implementation of each department and improve the measurement efficiency and data sharing. The feasibility of 3D measurement model construction and data management for aircraft digital assembly engineering is verified by using leading edge component of the wing box.

To solve the vibration problem during the edge trimming of thin-walled composite component with V-shape, and to explore the influence of cutting parameters on cutting force and workpiece vibration, experiments are designed based on the central composite response surface method in this study. The effects of spindle speed, feed rate, and cutting depth on cutting force and vibration acceleration are explored, and prediction models for cutting force and vibration acceleration are established. The optimal cutting parameters are obtained with the lowest cutting force and lowest vibration acceleration as optimization goals, which are spindle speed of 6000 r/min, feed rate of 400 mm/min and cutting depth of 1.4 mm. Research results of this study will help guide the selection of edge trimming parameters for thin-walled composite components with V-shape, so as to reduce vibration and improve surface quality during machining.