Three-dimensional braided composite materials are widely used in special-shaped structural parts in aviation, aerospace, military and other fields, but in order to ensure the quality of structural parts, it is necessary to carry out multiple trial productions to verify the effectiveness of the braiding process, which brings high costs. To address the challenges of high validation costs and prolonged optimization cycles in braiding parameter verification, this study proposed a universal simulation approach for special-shaped braided structures based on model reconstruction algorithms. Firstly, the centerline of the mandrel of the special-shaped structural parts was extracted based on the model data, and the key sections of the mandrel were regenerated based on the model outline, and the mesh of the model was reconstructed. Secondly, based on the kinematic characteristics, the fabric trajectory on the surface of the mandrel was generated, the interweaving relationship of the braiding process was analysed, the yarn trajectory was optimized, and the spatial topology and fabric structure model of the preform were generated. Finally, according to the braiding experiment, the accuracy of the method proposed in this paper is verified, and the error at the variable cross-section and variable curvature is not more than 5°. This innovative approach demonstrated strong compatibility with CAE integration platforms for braiding equipment, offering an efficient digital verification solution for composite manufacturing processes.

Titanium alloy investment castings have the advantages of high specific strength, corrosion resistance and heat resistance, as well as the advantages of high dimensional accuracy and low production cost. They have been widely used in key structural parts in the aerospace field. In order to promote the continuous improvement of domestic titanium alloy investment casting technology and the further application of titanium alloy investment casting products, this paper reviewed the application and development of titanium alloy investment casting technology in the aerospace field in recent years. Meanwhile, the titanium alloy investment casting process, high-temperature casting titanium alloys and the development progress of titanium alloy investment casting products are highlighted. The review for investment casting process focused on the key procedures of wax mold making, shell making, casting and post treatments. The review for high-temperature casting titanium alloys highlighted TC4, high-temperature near-α titanium alloys and intermetallic titanium aluminide alloys. The review for titanium alloy investment casting products mainly referred to structural parts of aerospace vehicle engines. Finally, the key issues existing in the domestic titanium alloy investment casting technology and application are summarized. Subsequently, the prospects of establishing a material database, reducing production costs, and developing casting simulation software are proposed.

With the continuous development of additive manufacturing technology, more and more additively manufactured materials and parts are used in aerospace, automotive manufacturing, medical devices and other fields. However, traditional mechanical property evaluation methods are difficult to effectively assess the complex mechanical properties of additively manufactured materials and parts due to the time-consuming experiments, high cost and limited data volume. Machine learning technology provides a novel and efficient solution for mechanical property evaluation of additively manufactured materials and parts through efficient data processing, multivariate analysis and feature extraction. This paper reviews recent research advances in machine learning for the evaluation of mechanical properties of additively manufactured materials and parts. First, the challenges of additive manufacturing technology in mechanical property evaluation are introduced. Then, specific applications of machine learning in the evaluation of tensile, compressive, fatigue and creep properties as well as fracture toughness are explored. Machine learning methods effectively overcome the limitations of traditional methods by improving prediction accuracy, reducing experimental costs, and accelerating evaluation. Finally, several challenges and pending issues in the application of machine learning in additive manufacturing are enumerated, and future research directions are envisioned.

Ceramic particles reinforced aluminum alloy is a highly promising structural material with great potential for aeronautical applications due to the advantages of high stiffness, high strength and excellent fatigue property. This paper takes TiB₂ particle reinforced 2024 aluminum alloy material with a mass fraction of 5% as the research object, conducts material fatigue performance test research, and compares the influence of variables such as different material batches, material directions, plate thicknesses, and stress concentration factors on material fatigue performance. The results show that the influence of material batches, material directions and thickness on the fatigue performance is relatively small when the stress concentration factor is 1.0. The inclusion of TiB₂ particles increases the fatigue limit by 30%. When K_t = 3.1, thickness shows some effects on the fatigue limit. The results provide a research foundation for the application of TiB₂ reinforced aluminum alloy in aeronautical applications.

Additive manufacturing of continuous fiber reinforced composites, as a key advanced technology developing rapidly in recent years, is having a profound impact on the development and production of aviation composites and components. The basic concept and general situation of continuous fiber additive manufacturing were introduced, and the research and application progress of this technology in the aviation field at home and abroad were elaborated. Considering the needs of application in the aviation field, the methods of improving the mechanical properties of continuous fiber reinforced composite additive manufacturing were discussed from different aspects including materials, design, and manufacturing. The research progress of digital simulation technology in the design, manufacturing, and mechanical properties simulation of continuous fiber reinforced composite additive manufacturing was analyzed in detail. The development prospect of the technology was summarized. Finally, the impact of continuous fiber reinforced composite additive manufacturing on the development and production of aviation composites and components was discussed. This technology is expected to provide significant support for the composite component research and aeronautical development.

7065 aluminum alloy thick plate with thickness of 125 mm was fabricated by semi-continuous casting→homogenization→hot rolling→solid solution→aging treatment. The microstructure evolution at different wall thickness positions of 7065 aluminum alloy thick plate and the mechanical properties of the aged alloy were studied by means of metallographic microscope, scanning electron microscope, transmission electron microscope, differential scanning calorimeter, X-ray diffractometer and universal stretching machine. The experimental results show that the as-cast microstructure of 7065 aluminum alloy thick plate is finer in the surface layer and coarser in the central layer, the volume fraction of η phase in the homogenized state is 64.5% lower than that in the as-cast state, and the deformation degree of the hot-rolled surface layer is the highest, while the deformation degree of the central layer is the smallest. In the aged microstructure, the precipitated phase is mainly the nano-scale η' phase precipitated in the grain, and the recrystallization degree and precipitated phase fraction of the surface layer are higher than that of the central layer. 7065 aluminum alloy thick plate has little difference in mechanical  roperties at different positions. Along the rolling direction (RD), the strength of the central layer is the highest, and the tensile strength, yield strength and elongation are 560.1 MPa, 539.6 MPa and 13.7%, respectively. Along the transverse direction (TD), the strength of the 1/4 layer is the highest, and the tensile strength, yield strength and elongation are 563.1 MPa, 541.3 MPa and 12.2%, respectively. This study provides a basis for the designing and fabricating 7xxx aluminum alloy thick plates with excellent comprehensive mechanical properties and homogeneity.

Carbon fiber reinforced plastic (CFRP)/TC4 stacks are widely used in aerospace fields. Drilling of CFRP/TC4 stacks is generally performed using a single-process method. In this study, ultrasonic-assisted drilling and pecking drilling were combined to form a novel ultrasonic pecking drilling (UPD) process for drilling these materials. The variation in drilling sequences for stacks significantly affects hole quality and tool wear. Therefore, this paper analyzes the thrust force, CFRP exit damage, and tool wear during UPD of CFRP/TC4 stacks. The results indicate that the drilling in the CFRP→TC4 direction reduces CFRP exit damage, with the maximum delamination factor decreased by 21.9%; Drilling in the TC4→CFRP direction generates lower thrust force and causes less wear on the tool’s main cutting edge; Scanning electron microscopy (SEM) observations and surface roughness measurements of the hole walls under both drilling sequences demonstrate that titanium chip entanglement in the TC4→CFRP direction improves hole wall quality.

In order to reduce the overall weight of pipeline systems and increase available space, the application of small bending radius pipes is becoming increasingly widespread. However, in free bending forming technology, forming small bending radius pipes is more difficult. Based on ABAQUS finite element simulation, this paper establishes a finite element model for the free bending forming of small bending radius pipes, analyzes the free bending forming process of small bending radius pipes, and forms pipes with a relative bending radius less than 2 by adding additional bending moments. The effectiveness of the finite element model is demonstrated through experiments. By means of finite element simulation and free bending test verification, the corresponding relationship between the process parameters of the pipe for free bending die forming and additional bending moment forming and its forming radius was obtained. The experimental results show that, the minimum relative bending radius achieved by the bending die is 2.07. By increasing the additional bending moment for forming, the minimum relative bending radius can be reduced to 1.75.

TA18 titanium alloy pipes are widely used in aerospace. Most titanium alloy pipes are bent and formed using CNC bending. This article focuses on the analysis of the bending performance of TA18 titanium alloy pipes, using a method that combines uniaxial tensile testing and finite element simulation. First, the mechanical properties of the pipe were tested to obtain the material performance parameters. The finite element model of the pipeline was established based on various parameters. The corresponding bending die model was established based on the appearance requirements of typical CNC bending parts, and the CNC bending of the pipes was simulated and analyzed. At a 45° bending angle, the effects of friction coefficient, gap and bending speed on the maximum cross-sectional distortion and maximum outer wall thickness reduction of TA18 titanium alloy tube CNC bending forming were studied. Simulation and experimental results show that when the friction coefficient between the bending die and the pipe is increased while decreasing the friction coefficient between the pressure die/anti-wrinkle die and the pipe, combined with a 0.01 mm gap between the pressure die and the pipe, a bending speed of 0.15–0.5 rad/s, a pressure die feed speed of 8–16 mm/s, and an axial feed speed ratio of 1.1–1.2, the forming quality can be significantly improved. Under these conditions, both the maximum outer wall thickness reduction rate and the cross-sectional ovality distortion rate reach optimal values. The study verifies the necessity of parameters collaborative optimization and provides theoretical guidance for practical process parameters setting.

The aero-engine pipeline system is an important external accessory system to ensure the normal operation of an aero-engine. To improve the efficiency and quality of aero-engine pipeline design, this study analyzes the composition of the model based definition (MBD) dataset and summarizes the design experience and knowledge of designers, and proposes a rapid design method for aero-engine pipeline systems. This method is based on design criteria for pipelinerelated components accessory definition, layout, and laying. Based on the integration of KBE and MBD technologies, the aero-engine pipeline design system is developed through secondary development on the NX and Teamcenter software platforms. The system constructs various databases, model libraries, and knowledge bases, embeds design rules and standards into the process, achieves the management and sharing of pipeline data, and achieves the goal of quickly and intelligently designing aero-engine pipelines.