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Aluminium honeycomb sandwich structure with CFRP panels has broad applications in aerospace and other industries. This paper presents an experimental study on the eddy current (EC) testing of such structure. An EC probe consisting of two pancake coils, one up and one down, is used for the testing and the amplitude of the differential voltage of the coils at each position of probe scanning is measured. The result of linear scan shows that the local minimal EC responses correspond to the edges of the core walls. In the C-scan results, different types of defects in the honeycomb cores including wall fracture, node disconnection, and core wrinkle can be identified. Threshold processing is performed to improve the indication of the defects. Topological graph of honeycomb core is obtained by connecting the pixels of C-scan image at which the EC responses are the local minima. Detection of impact damages is carried out and the effects of impact energy on the C-scan image are analysed. When the impact energy is increased, the part of the image in the area of damage becomes more blurred, and the minimal signal decreases monotonically. The area of damage seen in C-scan image is not necessarily increased with the increase of impact energy. Highlights: The manuscript investigates the eddy current testing of aluminum honeycomb sandwich structure with CFRP panels, various core defects can be effectively identified, which have not been reported in literature. Linear and C scans are performed. The result of linear scan shows that the signal reaches minimum when the probe passes the edges of the core walls, then the topology of honeycomb core is reconstructed from the C-scan image based on this discovery and defect indication is improved. Detection of impact damages in the sandwich structure is also carried out and the effect of impact on C-scan image is analyzed. [ABSTRACT FROM AUTHOR]

Al–Si-based alloys are widely used in the automobile and aerospace industries, whereas high entropy alloys have emerged with many attractive properties. In this study, AlCoCrFeNi high entropy alloy (HEA) is employed to improve the properties of AlSi10Mg alloy through a metal matrix composite approach. Metal matrix composite powder mixture was sintered at 500°C using a hot press at a pressure of 50 MPa. HEA phase was found to be distributed uniformly. An increase of 20 and 40% in hardness and compressive strength were observed by reinforcing HEA in AlSi10Mg alloy. [ABSTRACT FROM AUTHOR]

This paper studies the buckling behavior of T-shaped composite stiffened panels reinforced by both straight and curvilinear sub-stiffening configurations subjected to compression. First, the simulated buckling response of the T-shaped stiffened composite panel is verified with experimental results from the existing literature. Subsequently, straight and curvilinear I-shaped sub-stiffeners are introduced into the design of the T-shaped stiffened composite panel. The distribution and laminate stacking sequence of straight and curvilinear sub-stiffened composite panels are optimized to improve buckling performance while maintaining a constant weight constraint. Further, a parametric analysis was implemented to assess the influence of the sub-stiffener curvature on the buckling response of the curvilinear grid sub-stiffened composite panel. Results demonstrate that introducing straight and curvilinear grid sub-stiffeners into the T-shaped stiffened composite panel improves buckling performance. Specifically, the introduction of straight sub-stiffeners results in a remarkable improvement of up to 200% in buckling performance, while introducing curvilinear grid sub-stiffeners exhibits an even more noteworthy improvement of up to 260%, which shows the superior design of curvilinear grid sub-stiffeners when compared to straight sub-stiffeners. This investigation delivers valuable insights into the design of sub-stiffened composite panels for improving structural performance, offering significant advantages for industries such as aerospace that require lightweight structures yet are resistant to buckling. [ABSTRACT FROM AUTHOR]

Real service requirements of the assembly performance and joining properties of design components are critical for composite usage in the aerospace industry. This experimental study offers a novel and comprehensive analysis of dry drilling optimization for glass-reinforced, high-performance epoxy matrix composites used in aerospace structures, focusing on thrust force and delamination. The study presents a first-time investigation into the combined effects of spindle speed (1000, 2250, 4000 and 5750 rpm), feed rate (0.2, 0.4, 0.6 and 0.8 mm/rev) and tool diameter (3 and 5 mm) using a custom-designed drill tool specifically developed for this application, filling a gap in the current literature. By employing the Taguchi design of experiments, the study identified that medium spindle speeds (2250–4000 rpm), lower feed rates (0.2 mm/rev) and smaller tool diameters (3 mm) provided optimal conditions for minimizing thrust force and delamination. These results present actionable insights into improving the structural integrity and performance of drilled aerospace-grade composite components, offering innovative advancements in both the aerospace and defense industries. [ABSTRACT FROM AUTHOR]

Wire Arc Additive Manufacturing (WAAM) technology, known for its low equipment and material costs, high material utilization, and high production efficiency, has found extensive applications in the fabrication of key components for the aerospace and aviation industries. The stability of the arc is crucial for the WAAM process as it directly affects the forming of the parts. In this study, the monitoring data of electrical signals and arc morphology during the WAAM process of 2319 aluminum alloy were investigated using a high-speed camera system and current/voltage acquisition system. By analyzing the current and voltage signals, as well as the arc imaging results, the influence of arc stability on the forming of the cladding layer was studied. The experimental results indicated that when both current and voltage exhibit regular periodic fluctuations, this manifests as a stable short-circuit droplet transition form, while sudden changes in these signals represent abnormal droplet transition forms. The adaptability of the process directly influenced the arc shape, thereby affecting the forming of the cladding layer. Under the process parameters of welding speed of 240 cm/min and wire feeding speed of 6.5 m/min, it was observed that the current signal exhibited a tight state and the variance of the arc width was minimized. This indicated that at a higher wire feeding speed, the droplet transfer frequency was increased. Under these process parameters, the arc output was more stable, resulting in a uniform metal coating. [ABSTRACT FROM AUTHOR]

The development and commercialization of aerospace vehicles have posed significant challenges to the performance requirements for the corresponding materials. To meet these challenges, ceramic matrix composites (CMCs) have been developed and are widely used in the aerospace industry. However, their stability under extreme environmental conditions still needs to be improved. In this review, some properties of zirconium carbide (ZrC), which are related to extreme environmental applications of CMC are discussed first. Then, the effect of ZrC on the properties of CMC is comprehensively reviewed. ZrC can be introduced into the matrix and coated on the surface to increase the ablation resistance. The protection mechanisms of ZrC addition to CMCs, and the improvement in ZrC ablation resistance are explained. In addition, some perspectives on future developments are given. [ABSTRACT FROM AUTHOR]

The high-speed centrifugal pump plays a crucial role in fields such as aerospace and petrochemical industries, owing to its characteristics of elevated rotational speed and high head. During high-speed operation, the centrifugal pump is prone to cavitation, which alters the fluid flow state within the pump, leading to vibrations, noise, and a sudden decrease in pump head and efficiency. Simultaneously, the collapse of cavitation bubbles generates impact pressure that can damage the pump's internal flow components, significantly reducing its operational lifespan and causing severe consequences. Moreover, under constant-flow conditions, the absolute and relative velocities of the fluid at the impeller inlet are functions of the suction pipe diameter. Therefore, there exists an optimal value for the impeller inlet diameter to enhance the centrifugal pump's resistance to cavitation. Similarly, the different geometric and structural parameters of the inducer also influence the hydraulic performance of the centrifugal pump. The focus of this study is on the external characteristics and internal flow patterns of an optimized high-speed centrifugal pump. In this paper, the entire flow field of the model pump is numerically simulated using ANSYS CFX software. The performance and overall flow field state of the high- speed centrifugal pump under different impeller configurations and inlet diameters are explored. The influence of blade wrap angle and inlet diameter on the high-speed centrifugal pump is revealed, providing a theoretical basis for subsequent optimal design. [ABSTRACT FROM AUTHOR]

Direct digital manufacturing (DDM) is the technology that provides the possibility of producing the final product directly from the 3D CAD model without the aid of any additional tools. Additive manufacturing is the main element of DDM for producing end-user products. The layer-on-layer creation of the product using additive manufacturing provides a lot of design freedom. The layer-on-layer production methodology enables the possibility of producing products with complex and freeform geometries. The layer-on-layer technology allows the material deposition only on the required spots, and hence a significant weight reduction is obtained during the manufacturing of products. Complex geometrical structures with light weight are the greatest interest of the aerospace, spacecraft, and automobile industries. Therefore, these industries have completely relied on novel lightweight materials for producing lightweight structures until now. However, novel lightweight materials are highly expensive and increase the cost of the products significantly. Recent studies show that additive manufacturing helps in producing lightweight structures with high structural stability without the need for expensive lightweight materials. The complete redesign of aircraft, spacecraft, and automobiles suitable for additive manufacturing increases the possibility of producing lightweight structures with high structural stability. The generative design method created for additive manufacturing opens up enormous design possibilities, but the complete redesign of the aircraft or spacecraft would take a few decades. Until then, redesigning and replacing some aerospace components are the most efficient way to achieve the goals in a certain percentage. This study aims to explore the possibilities of implementing DDM for small and medium manufacturing firms by combining the advances of computer application software, topology optimization, and additive manufacturing. The main classifications of aerospace components are static and dynamic. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Globally, with the advancement of industrialization and globalization, the automotive sector has drastically increased for transportation and commercial purposes. Hence, to maximize efficiency and minimize the weight of automobiles, the automotive and aerospace industries have welcomed synthetic fibre‐reinforced composites, vastly replacing conventional metals. Despite the superior performance, the usage of synthetic fibre composites has led to the massive dumping of automotive waste in landfills, making the land unfit for future purposes. Therefore, natural fibre‐reinforced composites (NFRCs) quickly replace synthetic fibres with their unique features, such as being lightweight, biodegradable, and non‐toxic, en routing a new path towards a sustainable environment. Though NFRCs are finding new applications in various industries, researchers are trying to enhance their thermal, electrical, and mechanical properties to make them synergic composites. However, with the presence of cellulose, lignin, and wax, natural fibres become highly responsive toward flammability, limiting their use in various emerging applications. As the subject of the flammability of NFRCs has a limited amount of literature, the current review article aims to address the current flammability studies and strategies adopted to improve the flame‐retardant characteristics of NFRCs exclusively. Also, this review covers the factors and influence of different types of flame‐retardant fillers adopted to improve the flame retreatant characteristic of NFRCs and their mechanism. Additionally, this review article summarises various official and laboratory flame‐testing techniques such as radial panel test (RPT), cone calorimetry, and limited oxygen index (LOI) adopted to characterize the flammable properties of NFRCs. Highlights: Natural fiber biocomposites are becoming a potential candidate for structural and interior applications in the automotive and aircraft industries.Flammability becomes a major alarm as it concerns with the safety of passengers.The flammability behavior of natural fiber composites is extensively discussed.Mechanisms, factors, and selection of flame‐retardant materials are reviewed to improve the flame‐retardant characteristics.The influence of surface treatments, fiber content, and flame‐retardant nanofillers are also elaborately discussed.Advanced flame testing techniques were conversed with pictorial representation. [ABSTRACT FROM AUTHOR]

The development of a corrosion-resistance surface on a desired industrial coating is a challenge in several industries. In the aerospace industry, it is necessary to modify the corrosion-resistant coating to address the susceptibility of damage during flight for aviation applications. The present study tested three types of commercially available corrosion-resistant coatings for aviation, and the coating with the best overall performance was modified to enhance its mechanical properties to prevent coating damage due to impacts from raindrops and sand during flight. Silica (SiO2) nanoparticles with an approximate particle size of 50 nm were prepared by the sol-gel method using tetraethyl orthosilicate (TEOS). The KH560 silane coupling agent, as the neck layer and the M2070 polyether amine as the crown layer, were covalently bonded and then grafted onto the surface of the nano-SiO2 core to obtain a core-shell structure of the SiO2 solvent-free nanofluid (SiO2@KH560-M2070). The tensile property of the polyurethane coating was improved when a small amount of the SiO2 solvent-free nanofluid was incorporated into the coating. The present study has theoretical and practical guiding significance for the selection and spraying of existing aircraft radome coatings. [ABSTRACT FROM AUTHOR]

The aerospace industry and technology are always considered one of the country’s most important and valuable industries. The research area of "Aerospace" is among the priorities of the grand science and technology development strategies, and addressing it is strategically vital. The present research aims to estimate and predict the appropriate algorithm for identifying high-quality aerospace researchers based on Advanced Ensemble Classifier Techniques (AECT) in data mining on the outputs of scientometric analyses and predicting the most essential scientometric-related metrics to identify high-quality researchers. The present study was performed using the protocols of applied research and multiple methods. The studied population includes all aerospace researchers (1945 and 2021) indexed in "The Web of Science Core Collection (WOSCC)". DataLab software and multiple programming languages have been applied in this research. All three algorithms have an accuracy of 0.96 and an F1-score of 0.97, which indicates that the models have high accuracy, validity, sensitivity, and predictive power. The "Blending" algorithm is considered a suitable and predictive model. The output of the LightGBM algorithm is that the most important and robust metric in the evaluation of prominent researchers is a metric from the researchers' effectiveness dimension, the Q parameter. According to the knowledge obtained from the ability to predict AECT in the prediction of highquality researchers, it is possible to use the metrics mentioned in the evaluation of researchers in the field of scientometrics for more accurate and comprehensive prediction. An algorithm that can lead to the optimal and efficient classification of researchers provides the possibility of in-depth analysis of the available data about researchers and smooths the predictive power of the most high-quality researcher. The use of the proposed algorithms in this research, while suggesting the appropriate algorithm, led to reliable and valuable knowledge in classifying high-quality aerospace researchers. [ABSTRACT FROM AUTHOR]

By simulating the thermomagnetization of Ba(Fe1-xScx)12O19 from approximately 100 to 750 K, the magnetocaloric effect (MCE) in Ba(Fe1-xScx)12O19 samples is approximated. Intriguingly, the thermomagnetic property of the undoped sample BaFe12O19 is described as a conventional MCE for high temperatures. However, at doping levels x of 0.128, 0.153, and 0.189, respectively, the thermomagnetic property of Sc-doped samples is defined as an inverse MCE below temperatures of 163, 239, and 318 K. In contrast, thermomagnetic property of Ba(Fe1-xScx)12O19 is described as conventional MCE above those temperatures. Additionally, Sc doping makes it possible for MCE in Ba(Fe1-xScx)12O19 to be strongly tailored. This is helpful for operating a magnetic refrigerator (MR) which occurs in various temperature ranges and results in a higher working temperature range. A promising function for Ba(Fe1-xScx)12O19 samples in MR at high-temperature applications in the automotive and food industries or aerospace. [ABSTRACT FROM AUTHOR]

The aerospace industry can benefit from conversational agents that provide efficient solutions for safety-of-life scenarios. This industry is characterized by products and systems that require years of engineering to achieve optimal performance within complex environments. With recent advances in retrieval and language models, conversational agents can be developed to enhance the system's question-answering capabilities. However, evaluating the added-value of such systems in the context of industrial applications, such as pilots in a cockpit, can be challenging. This article presents the design, implementation, and user evaluation of a conversational agent called Smart Librarian, which is tailored to the aerospace domain's specific requirements to support pilots in their tasks. Our results based on a controlled user experiment with flight school students indicate that the user's perception of the usefulness of the system in completing the search task is a good predictor of both task score and time spent. The system's responses to the relevance of the topic is also a good predictor of task score. The perceived difficulty of the search task and its interaction with the relevance of the system's responses to the topic also play a key role in search performance. The mixed-effects models constructed in this study had large effect sizes, demonstrating participants' ability to assess their performance accurately. Nevertheless, user satisfaction with the system's responses may not be a reliable predictor of user search performance. Implications for the design of conversational agents based on the domain's specific requirements are discussed. [ABSTRACT FROM AUTHOR]

Cf/SiC composites are widely utilized in the aerospace industry due to their excellent properties. However, Cf/SiC composites are notoriously challenging to machine. The substantial cutting force and severe tool wear during machining often result in poor surface quality and low machining efficiency. This paper presented a corrugated helical PCD (polycrystalline diamond) tool, featuring a helical structure and an arc array micro-groove on the primary cutting edge, and these micro-groove structures are staggered, facilitating continuous material removal during the machining of Cf/SiC composites. The study investigated the milling force variations of the corrugated helical PCD tool when machining Cf/SiC composites under different milling parameters. A comparative study was conducted on the milling force, surface quality, and tool wear of corrugated helical PCD tool and commercial PCD tools. The experiment revealed that the milling force initially decreases and then increases with rising spindle speed and increases with higher feed rates per tooth, milling depth, and width. The newly designed tool exhibited lower milling force, superior machining surface quality, and extended tool life, approximately 0.7 times that of commercial PCD tools. The cutting performance of the corrugated helical PCD tool proved superior. Additionally, it was confirmed that the primary wear mechanism for the corrugated helical PCD tool cutting Cf/SiC composites was abrasive wear. [ABSTRACT FROM AUTHOR]

Hybrid manufacturing combines the simultaneous benefits of additive manufacturing (complex geometries, part consolidation, and mass customization) with the advantages of subtractive manufacturing (superior surface finish and enhanced dimensional accuracies) by integrating a suite of complementary traditional processes into a base platform of additive manufacturing. The use of hybrid technology has grown in recent years given its capabilities on repairing metallic structures, producing parts with conformal cooling features, and manufacturing functionally graded products. These kinds of capabilities are of great interest to the medical implant, energy, automotive, maritime, and aerospace industry sectors, among many other fields. This work investigated the mechanical properties of stainless steel (SS) 316L as a function of different tool paths strategies using an integrated 5-axis CNC hybrid Mazak system with a laser hot wire deposition system (LHWDS). This study includes the evaluation of different printing parameters and their impact on the quality of the printed bead as well as the incorporation of a structure–property material relationship based on the mechanical performance of the manufactured coupons. [ABSTRACT FROM AUTHOR]

Thermal protection was always a prominent issue in the aerospace industry. For vehicle safety, reliability and payload requirements, thermal protection materials were usually expected to possess low density, superior mechanical and thermal insulation properties. Here, lightweight and high-strength porous mullite-silica ceramics were manufactured using particle-stabilized foaming technique. The strength and thermal insulation properties of porous ceramics modified with hollow silica spheres were significantly enhanced. A 10 wt% hollow spheres addition achieved a 28.9 % increase in strength and a 33.4 % decrease in thermal conductivity with almost constant porosity (from 86.39 % to 87.04 %). Considering the characteristics of light weight, high compression strength and superior thermal insulation performance, porous ceramics could be applied as thermal protection materials in the aerospace sector. [ABSTRACT FROM AUTHOR]

By simulating the thermomagnetization of Ba(Fe1-xScx)12O19 from approximately 100 to 750 K, the magnetocaloric effect (MCE) in Ba(Fe1-xScx)12O19 samples is approximated. Intriguingly, the thermomagnetic property of the undoped sample BaFe12O19 is described as a conventional MCE for high temperatures. However, at doping levels x of 0.128, 0.153, and 0.189, respectively, the thermomagnetic property of Sc-doped samples is defined as an inverse MCE below temperatures of 163, 239, and 318 K. In contrast, thermomagnetic property of Ba(Fe1-xScx)12O19 is described as conventional MCE above those temperatures. Additionally, Sc doping makes it possible for MCE in Ba(Fe1-xScx)12O19 to be strongly tailored. This is helpful for operating a magnetic refrigerator (MR) which occurs in various temperature ranges and results in a higher working temperature range. A promising function for Ba(Fe1-xScx)12O19 samples in MR at high-temperature applications in the automotive and food industries or aerospace. [ABSTRACT FROM AUTHOR]

In the aerospace industry, an important number of machined parts are submitted for high-performance requirements regarding surface integrity. Key components are made of materials selected for their unique properties and they are obtained by milling processes. In most situations, the milling process uses cooling methods because, in their absence, the material surface could be affected by the generated heat (temperatures could reach up to 850 °C), the residual stress, the cutting forces, and other factors that can lead to bad integrity. Cryogenic cooling has emerged as a pivotal technology in the manufacturing of aeronautical materials, offering enhanced properties and efficiency in the production process. By utilizing extremely low temperatures, typically involving liquid nitrogen or carbon dioxide, cryogenic cooling can significantly enhance the material's properties and machining processes. Cryogenic gases are tasteless, odorless, colorless, and nontoxic, and they evaporate without affecting the workers' health or producing residues. Thus, cryogenic cooling is also considered an environmentally friendly method. This paper presents the advantages of cryogenic cooling compared with the classic cooling systems used industrially. Improvements in terms of surface finishing, tool life, and cutting force are highlighted. [ABSTRACT FROM AUTHOR]

The aerospace industry faces the challenge of maintaining product excellence amidst intricate processes and demands for cost and time efficiency. Mathematical modeling emerges as a valuable tool for optimizing the engineering process and enhancing quality, with potential applications extending beyond aerospace to other sectors with high quality and safety standards. This study develops and validates a mathematical model specific to the aerospace industry, aiming to assess the impact of human resource expertise on product quality. Through a case study within an aerospace organization, an IDEF0-methodology-based mathematical model, coupled with weighted averages, was constructed to depict the comprehensive engineering process and quantify knowledge's impact on deliverable quality. Simulation data, gathered through human resource knowledge assessments and non-conformity analyses, revealed a direct correlation between technical knowledge levels and deliverable quality, consequently impacting final product quality. The proposed model serves as a tool for estimating potential deliverable error rates and pinpointing critical areas within the process that necessitate refinement. The research underscores the significance of knowledge investment and effective knowledge management strategies in upholding quality and competitiveness across industries with stringent quality requirements. [ABSTRACT FROM AUTHOR]

Surface quality represents a critical challenge in additive manufacturing (AM), with surface roughness serving as a key parameter that influences this aspect. In the aerospace industry, the surface roughness of the aviation components is a very important parameter. In this study, a typical Al alloy, AlSi10Mg, was selected to study its surface roughness when using Laser Powder Bed Fusion (LPBF). Two Random Forest (RF) models were established to predict the upper surface roughness of printed samples based on laser power, laser scanning speed, and hatch distance. Through the study, it is found that a two-dimensional (2D) RF model is successful in predicting surface roughness values based on experimental data. The best and minimum surface roughness is 2.98 μm, which is the minimum known without remelting. More than two-thirds of the samples had a surface roughness of less than 7.7 μm. The maximum surface roughness is 11.28 μm. And the coefficient of determination (R2) of the model was 0.9, also suggesting that the surface roughness of 3D-printed Al alloys can be predicted using ML approaches such as the RF model. This study helps to understand the relationship between printing parameters and surface roughness and helps print components with better surface quality. [ABSTRACT FROM AUTHOR]

Maintaining the integrity and longevity of structures is essential in many industries, such as aerospace, nuclear, and petroleum. To achieve the cost-effectiveness of large-scale systems in petroleum drilling, a strong emphasis on structural durability and monitoring is required. This study focuses on the mechanical vibrations that occur in rotary drilling systems, which have a substantial impact on the structural integrity of drilling equipment. The study specifically investigates axial, torsional, and lateral vibrations, which might lead to negative consequences such as bit-bounce, chaotic whirling, and high-frequency stick-slip. These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system's components since they are difficult to be detected and controlled in real time. The study investigates the dynamic interactions of these vibrations, specifically in their high-frequency modes, using field data obtained from measurement while drilling. The findings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling system performance. The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems. Therefore, integrating these components can increase the durability of drill bits and drill strings, as well as improve the ability to monitor and detect damage. Moreover, by exploiting these findings, the assessment of structural resilience in rotary drilling systems can be enhanced. Furthermore, the study demonstrates the capacity of structural health monitoring to improve the quality, dependability, and efficiency of rotary drilling systems in the petroleum industry. [ABSTRACT FROM AUTHOR]

The dual compensation chamber loop heat pipe (DCCLHP) technology shows great promise for efficient thermal management in a variety of applications. This study focuses on refining the startup performance of the DCCLHP, particularly for low heat load conditions in terrestrial settings, by utilizing dual bayonet tubes. Empirical investigations examined the DCCLHP's operational characteristics and improved thermal transfer capabilities across different orientations of the evaporator and compensation chamber (CC), including vertical, 45‐degree tilt angle, and horizontal configurations. Key results demonstrate the DCCLHP's ability to manage low heat loads across diverse orientations, achieving over 400 W of heat transfer across a distance of 2.0 m while maintaining stable operation. Notably, the DCCLHP operation did not exhibit any significant instability issues. This work enhances the startup performance of the DCCLHP in various orientations and provides valuable insights into the confined natural circulation phenomenon, crucial for improving the overall thermal management capabilities of the system. In summary, the study highlights advancements in DCCLHP design and its potential to address thermal management challenges in diverse applications, particularly in the aerospace industry, through improved startup performance and enhanced heat transfer capabilities. [ABSTRACT FROM AUTHOR]

Most large aerospace cylindrical components still adopt a manual aligning method with low automation, large manual intervention, and heavy dependence on operator workers, resulting in the low quality and efficiency of large component aligning, which seriously prolongs the manufacturing time of aerospace products. To cope with this issue, based on closed-loop adaptive control and digital twin (DT) technologies, an adaptive aligning system for large cylindrical components, i.e., the DT aligning system, is proposed in this study. For the DT aligning system, through the DT multi-dimensional modeling, i.e., geometric modeling, physical modeling, functional modeling, and data modeling, it can be divided into a physical space, a virtue space, and twin data. Note that the association, mapping, and interaction between physical space and virtual space of the aligning system can be realized via the twin data, thereby realizing real-time virtual display, monitoring, and control of the large component aligning. In addition, based on the measured pose data, aligning stress, and predicted aligning error, an adaptive force/position control method for large component aligning is proposed, and it can achieve real-time decision-making and precise execution of the aligning process. Finally, through application validation, the DT process system can realize the real-time status perception and process execution decision during the large component aligning. Finally, through experimental validation, it is found that the proposed system, i.e., the DT aligning system, can improve the quality and efficiency of the large aerospace cylindrical component aligning, as well as the automation and intelligent level of the aligning system. [ABSTRACT FROM AUTHOR]

Thin-walled composite cylindrical shells are nowadays widely used as primary structures in the aerospace industry. The so-called variable stiffness (VS) composite cylindrical shells with flexible stiffness tailoring characteristics have been made possible by existing AFP techniques. Considering the inherent imperfection sensitivity property of axially compressed thin-walled cylindrical shells, the buckling behaviors of the axially compressed VS composite cylindrical shells with initial geometric imperfections and delamination imperfections are investigated respectively in this paper. The design buckling loads of the axially compressed VS composite cylindrical shells are first determined by the probing method, which is verified by comparing with the existing test data and numerical simulation results. Additionally, a parametric study is conducted to investigate the effects of delamination imperfections on the buckling loads. The constraint delamination sizes of the VS composite cylindrical shells based on the design buckling load in this paper are given. Furthermore, the effects of continuously variable fiber angles on the buckling loads are investigated considering the imperfection sensitivity. The specific VS composite cylindrical shells with both high- buckling loads and low-imperfection sensitivity are obtained. Results indicate that the effects of imperfection sensitivity need to be carefully considered in buckling design of the axially compressed VS composite cylindrical shells. [ABSTRACT FROM AUTHOR]

It is a known fact that aerospace industry requires very strict requirements in terms of weight, material properties, and product lifetime performance. Therefore, composite materials are key candidates to satisfy these stringent requirements. Thermoplastic composites have become more competitive in the fields of aerospace, defense, energy, electronics, and automotive industries compared to thermoset composites, due to their ease of formability, short production cycles, and recyclability. Considering the benefits of thermoplastic composite materials, more thermoplastic parts will be produced in near future in aerospace industry. This study highlights the most recent advancements in thermoplastic composite technology. The latest advances in thermoplastic composite technology are highlighted by reviewing material technologies and production methods. Conclusion of this study, it has been observed that the use of thermoplastics in the aerospace industry is increasing day by day, owing to the advantages they offer compared to traditional materials. Especially in critical and trending areas such as stamp forming, press consolidation, Automatic Fiber Placement (AFP), and welding methods, research and development activities are intensifying. Furthermore, this study provides insights into the direction of current investments in thermoplastic technology and discusses how these investments are likely to shape future applications within the aerospace industry. [ABSTRACT FROM AUTHOR]

The usefulness of the supersonic jet is inhabitable in the Aerospace industry. However, control of the supersonic jet is important for efficient mixing and noise attenuation. Particularly, asymmetric jets are better than axisymmetric jets in rapid mixing. Considering this, the experimental investigation has been carried out for the vortex generators or tab-controlled Mach 1.6 elliptic jet. To compare the impact of the locations of the vortex generators, they are deployed at the diametrically opposite locations of the nozzle outlet along the major or longest axis and the minor or shortest axis, respectively. The investigations have been carried out using the centerline pressure distributions employing the Pitot probe and the Schlieren flow visualizations. A maximum of 66.43% reduction in supersonic length has been observed from the centerline pressure distributions for the vortex generator placed along the shortest axis. In addition, the Schlieren flow visualizations confirm substantial distortions in the shock cell structures when the vortex generators are placed along the shortest axis which results in noise mitigation. The study concluded that the impact of the vortex generator, placed along the shortest axis, is superior in the manipulation of shock cell structure, efficient mixing, and thereby noise mitigation than those placed along the longest axis. [ABSTRACT FROM AUTHOR]

Part features, such as dents, holes, and bumps, are integral to the thin-walled sheet metal components used in the automobile and aerospace industries. These features are often required to be suppressed for more agile and reasonably accurate results during the CAE analysis. However, identifying these features is a critical task usually performed by experts. It requires a detailed analysis of the CAD model, which largely depends on the importance of each feature, feature size, and domain boundary conditions. Thus, identifying such features is a challenging task. This work proposes a novel data-driven approach to create an intuitive model that identifies suppressible features on CAD models of sheet metal parts. The dataset to train the supervised learning model is generated by extensive finite element analysis of the part models. The case studies show that the trained Machine learning model gave good test accuracy. [ABSTRACT FROM AUTHOR]

The article presents Plastics Metal Stir Welding (PMSW) as a groundbreaking technique from Royos Joining Solutions GmbH that enables the durable connection of various thermoplastics with metals, significantly enhancing production efficiency and material versatility in industries like automotive and aerospace. It states that this innovation allows for reliable welding without the need for pre-treatment, streamlining the manufacturing process.

This study investigates the drag coefficient of three models of suborbital rockets with different nosecones. A test section allowing for force measurement of a 1:50 scale rocket model was designed with the aid of numerical simulations. The velocity obtained in the wind tunnel corresponds with a Mach number of 2.45. RANS simulations were used in verifying operating parameters, as well as testing the support configurations for connecting the model with the bottom wall of the tunnel section. Pressure distribution measurements on the top and bottom walls of the wind tunnel matched simulation results well. The shock structure in the test section was visualized using the schlieren technique, revealing that the measured angle of the main shock generated at the tip of the rocket matched the simulation data. Finally, the measured forces were compared with simulations for one of the nosecone configurations. Despite very good agreement for pressure distribution on the wind tunnel walls and shock structure, a significant mismatch in the forces measured was nevertheless observed: the simulated CD (0.57) being four times larger than that obtained in measurements (0.138). Further analysis of the test section is required to pinpoint the source of discrepancies and redesign the force measurement system to achieve improved force results. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangdong University of Technology is the property of Journal of Guangdong University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

New environmental regulations have led to major changes in aluminum corrosion protection by prohibiting, for example, Cr(VI). Thus, the assessment of the corrosion behavior of Cr-free systems under atmospheric conditions is a major topic of interest for the aerospace industry. One major difficulty in this task is the lack of robust and reliable accelerated corrosion test(s) in this field. The aim of the present study is to compare the results of various accelerated corrosion standards (ASTM B117, ISO 4623-2, VCS 1027,149) to results obtained after 5 years of exposure at a marine atmospheric site in Brest, France. Additional accelerated corrosion tests were designed by varying several parameters in the VCS 1027, 149, such as the salt concentration, the time of wetness, and the relative humidity. The different modes of failure obtained in accelerated corrosion tests on the painted samples were then compared to field exposures in a marine atmospheric site. The first results obtained showed that the developed tests are more representative of service conditions than standard tests. [ABSTRACT FROM AUTHOR]

Additive manufacturing, or 3D printing, is a process where a part is produced layer by layer, and represents a promising approach for designing components close to their final shape. Titanium alloys produced by additive manufacturing find application in various industries. This overview examines the features of the formation of the microstructure and properties in Ti alloys synthesized with the use of powder and wire laser additive technologies, as well as solid-phase methods of additive manufacturing such as friction stir additive manufacturing. Their main drawbacks and advantages are discussed, as applied to Ti alloys. The main approaches to solving the problem of increasing the strength properties of the synthesized Ti workpieces are considered. The authors of this overview propose a new area of research in the field of the application of additive technologies for producing ultrafine-grained Ti semi-products and parts with enhanced performance characteristics. Research in this area opens up prospects for designing heavily loaded complex-profile products for the aerospace, oil and gas, and biomedical industries. [ABSTRACT FROM AUTHOR]

This scientific article aims to analyze in depth the problems and challenges faced by the aerospace industry in Indonesia from the perspective of business law. This research will use a qualitative approach to deeply understand the legal issues affecting the aerospace industry. This approach allows researchers to explore the experiences, views, and interpretations of various stakeholders. This research method is designed to explore and analyze the legal aspects of business in the aerospace industry in Indonesia. The main focus is on understanding how regulations and laws affect operations and compliance in the industry and how they impact airlines, aircraft operators, and passengers. The results of this study from the researcher's perspective provide an insight and reference where the importance of adaptive business models and flexible regulations in the aviation industry is important. Technological innovations such as electric aircraft and drones offer the potential to improve efficiency and sustainability, but they require the right regulatory support. On the other hand, customer satisfaction remains key to business success, especially through responsiveness to complaints and adjustment to changing expectations due to global events such as COVID-19. Collaboration between all stakeholders is needed to create an environment that supports growth and innovation in the industry. [ABSTRACT FROM AUTHOR]

Copyright of Mevzu is the property of Ali Sever and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights Composite structures in the aerospace and railway industries frequently experience single or multiple low‐ or high‐velocity impacts. The dynamic behavior of composite structures under single impacts cannot be extrapolated to multiple impacts. This study investigates the influence of the distance between projectiles in simultaneous multiple impact scenarios using a finite element model for multiple impacts on carbon fiber‐reinforced polymer (CFRP) laminate plates. The critical distance between projectiles, where stress wave interaction becomes significant, was identified. Results indicate that a distance between the centres of the projectiles of approximately two to three times the projectile diameter is the most damaging for simultaneous multiple impacts. A finite element model for multiple impacts on CFRP laminate plates was developed. Four different distances between projectiles were evaluated. The ballistic limit, out‐of‐plane displacements, energy absorption, and related parameters were studied. A distance of twice the projectile diameter was identified as the most critical. The distance between projectiles significantly affects the synergistic effects. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced plastic (CFRP) is a widely used material in the aeronautical and aerospace industry. Hole-making operations on CFRP frequently generate hole-exit damages which are related to the axial cutting force. As an alternative hole-making process, helical milling presents several advantages when compared to conventional drilling process. In order to study the mechanism of hole-exit damages in helical milling of CFRP, the axial cutting force during cutting process should be investigated in advance. Although CFRP is known as a difficult-to-cut material just because of being composite and non-homogeneous, the impact of composite structure and non-homogeneity on the axial cutting force has rarely been considered in the published researches of helical milling. This paper aims to investigate the axial cutting force in helical milling of CFRP, considering the composite structure and non-homogeneity of workpiece. The detailed laminated structure of the CFRP workpiece was investigated and the experiments of axial cutting forces were carried out. The results show that a periodic and fluctuant axial cutting force is generated in helical milling of CFRP. The periodic fluctuation of the axial cutting force was verified to be related to both the composite structure and the deformation of uncut material. Then, a cutting model was built to explain the changing process of axial cutting force during cutting process. [ABSTRACT FROM AUTHOR]

In recent years, with the development of deep coal mines and petroleum resources and the expansion of the aerospace industry, the pursuit of heat-resistant energetic materials with high thermal stability and high energy has been increasing. Bis(4-nitropyrazole) was employed as an energy bridge to link 1,2,4-triazole, thereby constructing a sophisticated tetracyclic framework in this study. A tetracyclic heat-resistant explosive 5,5′-(4,4′-dinitro-2H,2′H-[3,3′-bipyrazole]-5,5′-diyl)bis(4H-1,2,4-triazole-3,4-diamine) (3) and its derivatives 6–8 with excellent comprehensive performance have been successfully prepared. Particularly noteworthy is that compound 3 has a detonation velocity of 8604 m s−1, which exceeds that of the conventional heat-resistant explosive HNS with a velocity of 7164 m s−1. Furthermore, compound 3 has higher thermal stability (Td = 340 °C) than HNS (Td = 318 °C). In addition, the tetracyclic compound 3 also exhibited extraordinarily low sensitivity (IS > 40 J; FS > 360 N). These unique characteristics make it a potential candidate for novel heat-resistant and insensitive energetic materials. [ABSTRACT FROM AUTHOR]