As aerospace technology rapidly progresses and space environments become more sophisticated, the need for aircraft components made of lightweight, thermally insulating, and advanced thermal conductive materials has soared. The research of triply periodic minimal surface (TPMS) structures has grown into a research hotspot due to their unique thermal and mechanical properties. However, research on the thermal conductivity of TPMS structures featuring varying cell sizes is quite limited. Therefore, this research proposes a new method for gradient adjustment of TPMS cell sizes. A constant temperature heating experiment at 300 °C was conducted on four TPMS wings with different cell size gradients using an active cooling experimental platform, and comparisons were made with two TPMS wing structures with uniform cell sizes. The results showed that within the inlet velocity range of 1.06–12.72 m/s, the wing with a cell size of 10–12–10 mm exhibited the highest overall convective heat transfer coefficient. Compared to wings with cell sizes of 10 mm, 12 mm, 10–12 mm, 12–10 mm, and 12–10–12 mm, the overall convective heat transfer coefficient of the 10–12–10 mm wing increased by 1.3–6.2%, 28.8–63.2%,15.1–44.6%,7.5–33.5%, and 21.2–49.6%, respectively. Additionally, in accordance with the experimental measurements, the relationships between the Nusselt number, friction coefficient, convective heat transfer coefficient, overall heat transfer coefficient, and Reynolds number were geometrically defined. The results of this study offer a strong theoretical foundation and actionable insights for effective thermal regulation of aircraft surface configurations in the production of the lightweight aviation manufacturing industry.

Gyroid structures designed and manufactured by triply periodic minimal surface (TPMS) are ideal for building complex thin-walled structural components, due to their good thermal convection properties. This study proposes a method for quantitatively analyzing the thermal convection performance in Gyroid structures with various unit cell sizes. This allows to study the impact of the unit cell size on the fluid flow and thermal convection performance within the Gyroid structures. A lattice porous structure thermal convection experimental platform was first built, and implicit function models for eight different lattice structures, having the same porosity, were constructed. The thermal convection performance was then experimentally studied. Finally, numerical simulations of eight of the Gyroid models were conducted to study the impact of the unit cell size on the thermal conduction performance. The obtained results show that, for a unit cell size of 10 mm and for the same porosity, the Gyroid model has the largest thermal convection coefficient and the highest comprehensive heat transfer coefficient. Compared with Gyroid model with unit cell sizes of 20 mm and 5 mm, the convective heat transfer coefficients are respectively increased by 45.5-69.3 % and 17.1-37.4 %, and the comprehensive convective heat transfer coefficients are respectively increased by 57-75.8 % and 30-52.4 %. In addition, an empirical equation for the relationship between the Nusselt number, friction coefficient, and the unit hydraulic diameter (Rs) was established based on the experimental data. This study lays a foundation for the future manufacturing requirements of lightweight and high-heat dissipation in the thermal management fields.

Thermal management for hypersonic vehicles requires heat-exchange structures capable of dissipating high thermal loads while maintaining low flow resistance. Triply periodic minimal surface (TPMS) structures show promise for such applications because of their continuous flow passages and large heat-transfer surface areas. This study investigates the thermal-hydraulic behavior of anisotropic Gyroid TPMS structures and develops a gradient-composite design based on the identified flow and heat-transfer mechanisms. Three homogeneous and six anisotropic configurations were constructed by independently regulating unit-cell dimensions along three orthogonal directions. Their performances were evaluated using forced-convection experiments and computational fluid dynamics simulations over inlet volume flow rates of 12–120 L/min.The results show that the thermal-hydraulic response strongly depends on the direction of anisotropic deformation. Streamwise compression intensifies flow deflection and thermal boundary-layer disturbance, whereas streamwise elongation produces smoother flow paths and lower resistance but weakens convective heat transfer. The transversely compressed TPMS5 and TPMS6 structures enhanced heat transfer, while the streamwise-elongated TPMS7 exhibited the lowest flow resistance. Based on these complementary characteristics, a gradient-composite TPMS-G structure was designed by spatially integrating heat-transfer-enhancing and low-resistance units. Over their respective Reynolds-number range, the thermal-hydraulic performance evaluation criterion (j/f1/3) of TPMS-G was 1.4–2.8% higher than that of TPMS5 and 17.9–29.0% higher than that of TPMS7. Its friction factor was 47.1%–53.7% lower than that of TPMS5 and differed from that of TPMS7 by no more than 6.2% over the common Reynolds-number range. The proposed design provides a mechanism-informed route for balancing heat-transfer enhancement and flow resistance in TPMS-based heat exchangers and thermal-management devices.

This study investigates the ballistic resistance of 3D-printed AlSi10Mg wing structures with internal triply periodic minimal surface lattices. A finite element model simulating impact by a 9mm tungsten sphere was validated experimentally. Results show unit cell geometry critically determines performance. At 20% volume fraction, the Diamond sheet exhibits the highest resistance. Optimizing the aspect ratio of a 10% volume Gyroid solid suggests a 20% increase in energy absorption, yielding a 16.9% better performance than a traditional solid wing with 20% volume, providing guidelines for lightweight UAV wing design..

Modern defense missions increasingly demand weapon systems capable of rapid deployment and establishing wide-area protective zones. This study investigated the explosive canister opening process and fragment dispersion dynamics of 12.7 mm fragmentation warheads designed for machine gun platforms. Using LS-DYNA with an ALE-based fluid–structure interaction algorithm, the complete transient response sequence was simulated, from detonation initiation and structural failure to fragment release. Three fragment geometries (cylindrical, square, spherical) and three axial detonation positions were comparatively analyzed. Results reveal a progressive structural failure sequence and bidirectional axial motion of fragments. Square fragments achieve the highest stable radial velocity ( 150 m/s) due to their larger pressure-bearing surface, outperforming cylindrical ( 140 m/s) and spherical fragments ( 120 m/s). The fragment closest to the initiation point consistently attains the maximum radial velocity. These findings provide theoretical support for the structural optimization and initiation design of small-caliber fragmentation warheads, thereby enhancing their short-range defensive effectiveness.

The exceptional mechanical properties and high-temperature resistance of 2.5D carbon fiber reinforced silicon carbide ceramic matrix composites (C/SiC) have demonstrated a wide range of potential applications in the field of aero engine turbine blades. In response to issues such as the appearance of a large heat-affected zone (HAZ) during laser-induced ablation (LIA) and the formation of oxides that cause significant taper in micro holes. This paper presents a chemical micro fluid assisted laser induced plasma micro-drilling method to improve taper and HAZ. The surface quality, thickness of the HAZ, taper, surface chemical composition, and mechanical properties of the micro holes processed by two varieties of micro fluid, NaOH and HF, were comprehensively analyzed. The findings indicate that the HF micro fluid assisted laser induced plasma micro-drilling procedure offers substantial benefits. In comparison to LIA, the HAZ’s thickness is reduced by 78.12%-80.46%, the taper is reduced by 45.71%-46.36%, the average tensile strength in high-temperature environments increased by 5.81%, and the equivalent strain distribution was also more uniform. The micro holes’ edges are regular, and the sidewall surface is smooth. This study provides a new method for 2.5D C/SiC micro hole processing and new ideas for improving the quality of laser processing.

At present, aluminum alloys are being increasingly used in lightweight protective structures; however, research on the damage mechanisms of such materials remains quite limited. This paper investigates the effects of the length-to-diameter (L/D) ratio of blunt projectiles, target plate thickness, penetration incident angle, and angle of attack on the penetration capability of 6061-T6 aluminum alloy plates, as well as the deformation characteristics and failure modes of the target plates. The findings indicate that the penetration performance of the projectile against the target plate is inversely proportional to the incident angle, a smaller L/D ratio, and the increasing angle of attack. Moreover, at smaller incident angles, the penetration performance of the projectile is paradoxically lower than under larger incident angle conditions. In addition, this paper proposes a predictive model for the residual velocity and the critical penetration velocity of projectiles after penetrating the target. This study provides a theoretical basis and technical guidance for the future design and optimization of anti-armor technologies.

The application of microtransfer technology to the manipulation process of microdevices is an area of current research. In the context of temperature-controlled microtransfer technology, the shape memory polymer (SMP) stamp plays a crucial role in microdevice manipulation, particularly surface adhesion. Aiming at the current problems such as the complexity and high cost of the SMP surface microstructure preparation process and the difficulty of surface adhesion adjustment leading to the inflexibility of microdevices pick and release, this study investigated the nanosecond ultraviolet (UV) laser ablation of superhydrophobic structures on the surface of SMP stamps and the adjustment of the surface macro-micro adhesion. The surface of the SMP stamp was ablated by laser direct writing to form a microgrid structure, which was then chemically modified to realize the superhydrophobic property of the originally hydrophilic stamp. It was found that when the surface microstructure of the SMP stamp was subjected to vertical thermal pressure, the surface microstructure of the stamp was deformed. The hydrophobicity of the whole stamp surface was weakened, and the surface adhesion was changed. Due to the shape memory property of the SMP stamp, the original microstructure state can be restored by simple heating, and the surface is still superhydrophobic after many cycles of vertical thermal pressure recovery. In this study, the superhydrophobic preparation process of the stamp surface is greatly simplified. The fine-tuning of the adhesion and wettability of the stamp surface is accomplished by changing the temperature. The macro-tuning of the stamp surface is accomplished by the regionalized design. Finally, in-plane programmable microtransfer printing was realized according to the established graphic layout of the microdevice. The macro-micro tunable adhesion superhydrophobic SMP microtransfer stamp surface has many applications in microdevice manipulation, microelectronic device assembly, and microelectromechanical system construction (MEMS).

The TPMS lattice structure is widely utilized in the military UAV field, thus it is imperative to investigate efficient methods for targeting the TPMS lattice structure. This paper conducts a numerical simulation to study the impact of exponential bullets on the penetration capability of lattice structures with varying thickness and density. Specifically, the analysis focuses on the penetration behavior of variable density Diamond structures designed using MATLAB and simulated using ABAQUS. The simulation results reveal that as the thickness of the lattice structure increases, there is an initial rise followed by a decline and then another increase in the increase rate of bullet velocity. Furthermore, it is found that the position and radius of the distortion axis significantly influence bullet velocity disparity, with deviation rates reaching 17.12 and 27.48

Carbon fibre-reinforced plastic (CFRP) is an excellent non-metallic composite material with advanced mechanical properties. Laser-induced plasma micro-machining (LIPMM) is a high-quality method of processing CFRP with less thermal damage. This study explored the interaction mechanism between plasma and CFRP material at different liquid depths and laser energies. A numerical model considering heterogeneity and anisotropy was proposed to study the anisotropic heat transfer of CFRP. The relationship between the plasma plume and material ablation was also investigated. The results revealed that a considerable ablation depth was obtained with a high aspect ratio of the plasma. In addition, the influence of surface tension on bubble attachment was studied, and it was found that decreasing the surface tension of a liquid could reduce bubble attachment. Machining CFRP by LIPMM in 40% ethanol solution can effectively reduce the bubbles on the sample surface and improve the processing quality. As the thermal conductivity of the liquid medium is greater than that of the air, the thermal damage of epoxy resin was effectively reduced. The ablation depth with LIPMM increased by about 17.5% compared to laser process in air.

With the rapid development of aerospace technology, the operation of aircraft in high-speed and hightemperature environments imposes higher demands on thermal management. Traditional heat dissipation methods can no longer meet the needs of modern aerospace vehicles. Therefore, to ensure the reliable operation of aircraft in extreme thermal environments, finding an efficient and lightweight heat dissipation model has become an urgent need. This study proposes a cell wall thickness regulation method based on a sinusoidal gradient function (Sin(omega t)) for the Diamond-type TPMS structure, creating a novel Diamond TPMS structure named Sin-Diamond. Using a combination of numerical simulation and experimental validation, the forced convection heat transfer performance and flow resistance characteristics of this heat dissipation model in air media were studied. The researchers conducted a comparative analysis of the heat transfer performance parameters of the constructed Sin-Diamond heat dissipation model. The results show that, within the velocity range of 0.42-4.17 m/s, when omega is set to 3, compared to the classical Diamond model, the Nusselt number of the SinDiamond model increases by 3.3 %-11.9 %, and the overall convective heat transfer coefficient (j/f) increases by 4.47 %-15.5 %, achieving an optimal balance between heat transfer efficiency and fluid resistance. This innovative research provides theoretical support and application innovation for the development of the aerospace field and has potential value in promoting the technological advancement of the aerospace manufacturing industry.

The triply periodic minimal surface (TPMS) is considered an ideal choice for constructing surface structure of high-speed aircraft due to its excellent convective heat transfer. In recent years, multi-morphology TPMS structures have attracted increasing attention in various fields, as they offer superior and more desirable properties compared to traditional TPMS structures with uniform units. However, the relationship between different morphologies of TPMS and their thermodynamic performance has not been extensively studied. This paper proposes a method to quantitatively analyze the heat dissipation performance of different lattice structures. We compared the heat transfer performance parameters of six minimal surface lattice structure models through experiments and simulations, finding a strong correlation between experimental and simulation results. The results indicate that under flow rate conditions of 2.08–4.58 m/s, the Gyroid-Sheet model exhibits the highest comprehensive heat transfer coefficient. Compared to the Gyroid-Solid, Primitive-Solid, Primitive-Sheet, IWP-Solid, and IWP-Sheet models, the comprehensive heat transfer coefficient increased by 15.2–20.1%, 212.6–277.9%, 110.2–137.6%, 12.5–25.7%, and 31.3–54.6%, respectively. Additionally, under the same experimental conditions, we compared the comprehensive heat transfer coefficients of the multi-morphology Gyroid-Primitive model and the Gyroid-Sheet model. The results show that the combined Gyroid-Primitive model has a comprehensive heat transfer coefficient that is 10.5–16.1% higher than that of the Gyroid-Sheet model alone. This study lays the groundwork for the application of lattice structures in surface structure of high-speed aircraft and provides a basis for meeting the design and manufacturing requirements for future lightweight structures with high heat dissipation capabilities.

With the rapid evolution of aerospace technology and the increasing complexity of space environments, the demand for lightweight, thermally insulated, and highly efficient heat dissipation materials in aircraft equipment has surged. This study addresses this critical need by investigating Triply Periodic Minimal Surface (TPMS) lattice structures, offering a novel design approach to enhance spacecraft thermal management under extreme temperatures. Our work introduces a methodology to quantitatively assess the thermal insulation and heat dissipation performance of various lightweight lattice sandwich structures. We constructed implicit function models of low volume fractions, including Gyroid, Diamond, Primitive, and IWP, and conducted experiments using an active cooling setup under controlled heating conditions at 300 degrees C. Key findings reveal that, at flow velocities ranging from 0.25 to 1.5 m/s, the Diamond model exhibited the highest convective heat transfer coefficient, surpassing the Gyroid, Primitive, and IWP models by 6.9 % to 427.3 %, 87.1 % to 485.6 %, and 1.5 % to 98.7 %, respectively. Conversely, at velocities between 1.5 and 3.75 m/s, the Gyroid model demonstrated superior heat exchange performance, improving by 14.6 % to 67.2 %, 73 % to 167.7 %, and 9 % to 64.8 % compared to the Diamond, Primitive, and IWP models. During thermal insulation tests at temperatures from 200 to 400 degrees C, the Diamond model showed the best insulation effect, while the Primitive model performed poorly. Based on the experimental data, we established empirical relationships between the Nusselt number, friction coefficient, and Geometric Surface Ratio (GS). These findings not only underscore the significant potential of TPMS lattice structures in aerospace applications but also provide a robust theoretical framework and practical guidelines for achieving efficient thermal management in lightweight aerospace manufacturing.

This study aims to enhance the combustion reproducibility and stability of tungsten-based delay compositions, focusing on a basic formula with the composition W/BaCrO4/KClO4 (38%/52%/10%). Relevant experiments were conducted to analyze the combustion characteristics by adding calcium fluoride (CaF2) to the composition. Seven tungsten-based delay compositions with varying calcium fluoride concentrations were prepared to examine the effects of this additive on combustion characteristics. In the experiment, the combustion rate was first tested, and the formula exhibiting the best combustion reproducibility and stability was selected. The microstructure of the optimal formulation sample was observed using scanning electron microscopy with energy dispersive spectroscopy, and the combustion product composition was analyzed with an x-ray diffractometer; Thermal analysis was performed on all formulations to investigate their thermal behavior. The experimental results indicated that a calcium fluoride content of 16% yielded the optimal combustion reproducibility and stability. Different formulations offered a wider adjustable range for combustion speed. This study provides both theoretical and experimental insights for regulating the delay time range of delay compositions.

Buried box culverts are crucial elements of transportation infrastructure. However, their behavior under foundation loads is not well understood, indicating a significant gap in existing research. This study aims to bridge this gap by conducting a detailed numerical analysis using the Finite Element Method and Abaqus software. The research evaluates the behavior of buried box culverts by examining their interaction with surrounding soil and the pressures from surface foundation loads. Keyvariables such as embedment depth, culvert wall thickness, concrete material properties, foundation pressure, foundation width, soil elastic modulus, and friction angle are altered to understand their combined effects on structural response. The methodology employs a validated 2D numerical model under plane strain conditions. Parametric studies highlight the critical role of culvert depth (H) in influencing earth pressure and bending moments. Foundation pressure and width demonstrate complex interdependencies affecting culvert behavior. Variations in culvert materials' elastic modulus show minimal impact. It was found that the lower wall of the buried culvert experiences higher average pressure compared to the other two walls, due to the combined effects of the culvert's weight and down drag forces on the side walls. Furthermore, while the pressure distributionon the top and bottom walls is parabolic, the pressure on the side walls follows a different pattern, differing from that of theother two walls

To solve the problems of incomplete information extraction and insufficient depth in the process of extracting the assem-bly feature information of complex 3D CAD assembly models,such as aircrafts、large conveyers which have many assembly parts and complex coordination,a method of extracting assembly feature information of complex products was proposed,which took CATIA software as the platform.Component Application Architecture(CAA)is used to develop the function of quick extraction of feature information.Combined with the idea of multi-tree pre-sequence traversal and the depth-first search algorithm,it can completely extract the fit and constraint information of multi-layer nested complex assembly,make full use of the feature informa-tion of complex3D CADassembly model,and more strongly support the assembly process planning.At the same time,the feasibil-ity of this method is verified by taking a civil aircraft wing conveyor as an example.

Cobalt-chromium-molybdenum alloy is used as a material for artificial human body components such as artificial hip joint and artificial denture and is often affected by electrochemical corrosion in human body fluids and saliva, which leads to inflammatory reactions and damage to the surrounding tissues as well as loosening and failure of the body components themselves. Few studies have been conducted to prepare corrosion-resistant coatings on the surface of Co28Cr6Mo. In this study, we used laser texturing to process a bionic 3D micronanocomposite structure on the surface of Co28Cr6Mo and quickly prepared a superhydrophobic and slippery surface coating with excellent corrosion resistance using polydimethylsiloxane solution and silicone oil modification. This surface had ultralow surface adhesion and good robustness of durability and abrasion resistance, reducing bacterial colonization or tissue adhesion and solving the problem of the lack of stability of the superhydrophobic surface. Microgrid grooves and layered nanoparticles were structurally responsible for the variation in wettability. The formation mechanism and composition of the prepared coatings were further analyzed. Electrochemical corrosion experiments were conducted on the surface in simulating body fluid and saliva environments, which showed the enhanced corrosion resistance of the prepared surface in the human body. These findings can further develop the surface functional modification of Co28Cr6Mo, accelerating basic and applied research studies on artificial human components.

基于Fluent软件中的6DOF动网格和重叠网格技术对超空泡射弹不同角度入水进行数值模拟仿真,研究了射弹入水角度对射弹的超空泡特性影响.仿真结果表明:射弹两侧空泡形态不对称,与左侧空泡相比,右侧空泡尺寸较小;射弹入水以后,入水角为15°时,偏航角、滚转角的波动范围更小,相对入水角为5°时,其入水稳定性更好;入水角度对射弹流动稳定阶段的滚转力矩、偏航力矩及俯仰力矩影响非常小,且入水后俯仰力矩处于持续增加状态.

采用基于机器视觉的无接触检测方式对飞机制造中蒙皮、机翼缘条以及角片等薄壁零件表面缺陷进行自动检测,使用VMS-4030G影像仪采集零件表面信息,提出多特征联合检测方法检测缺陷.该方法主要包括图像Tamura纹理特征提取、图像局部二值模式(LBP)直方图和LBP下的灰度梯度共生矩阵特征(GGCM)提取.根据缺陷特性选择提取特征,对得到的特征应用主成分分析法(PCA)进行降维以及支持向量机(SVM)分类,最终得到检测结果.为了验证所提方法可行性,以带铆接孔的6061铝合金板代替飞机薄壁零件进行数据采集和检测.试验结果表明,该检测方法对毛刺、裂纹、凹陷及划痕的检测率均大于92％,明显优于单一特征提取的检测方法.

Carbon Fiber Reinforced Plastics (CFRP) with superior mechanical properties are widely used in aerospace, automotive, and medical fields. The characteristics of CFRP with anisotropy and inhomogeneous result in poor machining performances by conventional drilling techniques. Laser drilling is a non-contact high precision machining technique without tool wear but leads to a large heat-affected zone (HAZ) and taper. Although underwater laser drilling could reduce thermal damage on CFRP surface, bubbles produced in the machining process severely affect the machining stability and surface quality. In this study, a micro fluid-assisted laser-induced plasma drilling (MFA-LIPMD) method was proposed to relieve the negative effect of bubbles as well as reduce the taper and HAZ. A comprehensive analysis of hole surface quality, HAZ, taper, and mechanical properties was conducted, and MFA-LIPMD performed more advantages over laser in the air (LIA) and laser-induced plasma drilling (LIPMD). It was found that the taper of micro-holes was reduced by 42.8%–51.78%, and the thermal damage rate of micro holes processed by the MFA-LIPMD process was reduced by 65.3%–68.1% compared with the LIPMD process, and the maximum tensile load of samples was increased by about 7.68%. Therefore, MFA-LIPMD has great potential for machining high-quality micro holes of CFRP plates.