Aircraft Parts Research Articles

Investigation of castability, mechanical, corrosion properties and flammability of ML-OPB and EWZ43 magnesium alloys

Magnesium alloys are usually considered as structural materials when the weight reduction is important - in aircraft and space industry for example. In recent years, there has been an increase in the use of new generation ignition-proof high-strength magnesium alloys in the design of aircraft parts. The properties of new ignition-proof casting magnesium alloys ML-OPB (Mg–6.7Y–2.6Zn–0.5Zr–0.35Ce– 0.35Yb; wt.%) and EWZ43 (Mg–3.8Y–4.4Nd–0.6Zr–0.6Zn; wt.%) were investigated and compared with properties of commercial magnesium alloys. The microstructure of investigated alloys in the as-cast condition comprises of a magnesium solid solution and a significant amount of eutectic. Heat treatment according to the T6 mode results in change in the eutectic phase’s morphology and also to their partial dissolution in the magnesium matrix. Long-term high-temperature holding, simulating operating conditions (500 h at 300 °C), leads to the formation of precipitates along the grain boundaries in both alloys, significantly reducing the mechanical properties. During the oxidation of the samples, it was established that the main components that involved into the oxide film and provides the protective properties of the alloys is Y, Nd and Yb. The investigated alloys have a high strength, which is not lower than that of the ML10 alloy. At the same time, the advantage of the ML-OPB alloy is a high elongation at fracture, while the EWZ43 alloy is characterized by high strength. The corrosion rate of the investigated alloys exceeds the corrosion rate of known commercial ML10 and AZ91 alloys, which implies the need for additional protection against corrosion of investigated alloys. At the same time, the castability of ML-OPB and EWZ43 alloys is no lower than that of most commercial magnesium alloys. An oxide film with high Y content and high protective properties is formed when the alloys interact with the sand mold bonded with furan resin. The ignition temperature of the investigated alloys is 100–150 °C higher than that of the ML10 alloy. The flammability test of alloys in the flame of a gas burner, made on cone samples and typical aircraft castings «bracket», showed that ML-OPB and EWZ43 alloys are almost non-flammable under the conditions of experiment.

Development of an Air Electric Compressor for a No-Bleed Environmental Control System of an Advanced Regional Aircraft

BACKGROUND: Aircraft designers strive to increase the fuel efficiency of aircrafts, including increasing the efficiency of aviation environmental control systems (ECS) by introducing an autonomous source of compressed air with an electric drive as part of aircraft.
 AIM: The present paper aimed to consideration of the results of research work (RD) of the technologies demonstrator for the electric compressor of the aircraft electric ECS and estimation of the performance and compliance of the simulated and experimental characteristics of this electric compressor.
 MATERIALS AND METHODS: Comparison of the simulated and experimental characteristics of the electric compressor of the electric ECS of the aircraft was carried out by confirming the compliance of the operating parameters of the technologies demonstrator for the electric compressor with those specified in the request for proposals (RFP), and by comparing the simulated and experimental values of the compression ratio of the compressor stage, isentropic coefficient of performance (COP), obtained during RD study.
 RESULTS: Information about the technical characteristics and design of the electric compressor is given and discussed. A comparative analysis of the presented simulated and experimental characteristics of the electric compressor has been carried out.
 CONCLUSIONS: Conclusions are drawn on the compliance of the compressor characteristics with the characteristics specified in the RFP; on the achieved level of readiness of the technology of the electric compressor for the electric ECS of the aircraft, on the need for experimental design work on the electric compressor, taking account of external influencing factors typical for an application as part of aviation equipment.

Basic design and technological solutions for the application of automated layout processes in the manufacturing of composite parts of passenger aircraft

Currently, there are great perspectives for the technology of manufacturing products and aggregates from PCM based on prepregs. Thus, the use of prepregs makes it possible to manufacture complex configuration parts in one technological operation. High competition and the increasing necessity of mass production of large-sized parts from PCM determines the emerging need for the use of automated layout equipment. The replacement of traditional, manual methods of layout by automated methods provides significant advantages, such as an increase in the quality of the resulting parts, a significant reduction in labor intensity of their production, an increase in accuracy and repeatability of the technological process of layout (reduction of defects) and, consequently, reduction of the cost of the finished product.

Разработка и сертификация летной годности современной ответственной детали корпуса переключателя для аэрокосмических систем, изготовленной из сплава AlSi10Mg с помощью аддитивной технологии

Aerospace applications can benefit from additive manufacturing (AM), which is highly advantageous for prototyping and rapid manufacturing. It also offers cost and weight savings, as well as integrated design capabilities. As of now, there are only a few AM standards available, many materials and equipment are involved, resulting in many variables that hinder certification and adoption. As a result, nonstandard testing is making AM in the airborne materials less appealing due to its costly and time-consuming nature. The main objective of this work is to manufacture the Selector Valve Body parts of military and civil aircraft through Laser Powder Bed Fusion (LPBF) process using AlSi10Mg powder. Further, this paper has been carried out the metallurgical properties, non-destructive and destructive testing as well as the clear explanation about the certification procedures. Moreover, this underscores the need for the developing guidelines and standards that cover all aspects of manufacturing from design to manufacturing to operation. A comprehensive analysis from liquid penetration test shows defects are within the permissible level. In addition, it exhibits higher yield strength, ultimate strength, and elongation of (259±4), (323±4) MPa, and (12.5±1.5) % respectively, along with factual evidence that the precipitation hardened AlSi10Mg indigenously developed and produced is equal in properties to the equivalent precipitation hardening aluminium alloys produced by internationally renowned manufacturers.

A Study on the Fatigue Life of the Laser Additive Manufactured Metallic Material

As more and more structural parts of military aircraft are formed with additive manufacturing (AM) technology, it was very urgent to study fatigue characteristics of additive manufacturing materials and structures. In order to study the fatigue life characteristics of aluminum alloy and titanium alloy manufactured by selective laser melting (SLM), a series of specimens with various structural details were designed and tested under constant amplitude and random spectrum. The basic reliability life of each test results was statistically analyzed and the reliability safety life curve was obtained. Fractography analysis showed that there were more defects and mixed failure characteristics in aluminum alloy specimens, while the fatigue-scatter of titanium alloy counterpart was larger than that of forgings.

Time Stacking Decision Tree for Oscillatory Failure Case Detection in a Flight Control System

Flight control systems are an essential part of aircraft, consisting of all elements between the pilot and the movable parts, such as actuators, controllers, and sensors, to control the aircraft's attitude, trajectory and speed. In this context, oscillatory failure cases are problems that can occur in any part of the flight control system, causing undesired oscillatory behavior that affects the aircraft's structural load. On the one hand, correctly detecting such failures enables weight saving to improve aircraft performance in different aspects; on the other hand, such detection enables reconfiguring the control law to keep the aircraft in its path. This work describes a data-driven oscillatory fault detection model and the control law reconfiguration for a fight control system for the Aerospace Industrial Benchmark. Preliminary results indicate that the developed system can accurately detect faults in several scenarios and properly reconfigure the control loop.

ANALYSIS OF THE ADVANCES IN THE DEVELOPMENT OF NEW GENERATION OF SUSTAINABLE, BIO-BASED AND/OR RECYCLABLE COMPOSITES

The introduction of polymer matrix composites in large structural parts for aircraft, buses, trains, and wind turbine blades has significantly boosted their efficiency. This is mainly due to the significant reduction in weight, resulting in fuel savings and a reduction on environmental impact. The annual use of these products is around 110.000 tonnes of carbon fibre composite parts and 4.5 million tonnes of glass fibre, with an average lifetime of around 15 years. Nevertheless, it should be noted that these products have high recycling disadvantages. Therefore, due to current environmental legislation, it is necessary to look for more sustainable alternatives, solutions to the waste generated during production, and at the end of life cycle. Key Words: bio-based composites, sustainable, thermosetting, vitrimers, natural fibres.

РАСШИРЕНИЕ НОТАЦИИ IDEF0 ДЛЯ ФУНКЦИОНАЛЬНОГО ОПИСАНИЯ ДИНАМИЧЕСКИХ СИСТЕМ

The development of rules for transitions between the design stages of dynamic systems: the goals of the system consumer, system requirements, technical solutions and consumer properties of systems, remains one of the most important aspects in the design of complex systems. The article implements an extension of the IDEF0 notation – a notation system for functions and their components. For a more detailed functional description of dynamic systems, an extension of the semantic notation language is introduced. Such an extension allows getting more detailed information about the system as a whole, and creates links between the functional and behavioral models. Extended semantics is applied to the design of functional descriptions of the aircraft parts. The notation extension is also a component of the lifecycle management system under development, that, in particular, should solve the issue of engineering semantics deficiency, not allowing to ensure in the elaborating processes the correspondence between requirements and technical solutions, the verification of those relationships and the validation of the system being developed. As a result, the expansion of the IDEF0 notation, new, expanded properties of the system model will be formed, which contribute to solving validation and verification problems in the development of complex technical systems.

Effects of Cryogenically Treated CFRP Composite on the Buckling Behavior in the Adhesively Bonded Beam

Carbon fiber reinforced plastic (CFRP) composite materials have favorable mechanical and physical properties such as low density, high strength-to-weight ratio, high fatigue resistance and high creep behavior, and high stiffness. Thanks to these unique properties, they produce aircraft parts such as outer flaps, carry-through structures, and center wing boxes and automotive parts such as body panels, engine components, and structure members. However, studies have been continuously performed on improving the properties of CFRP composite materials. Recently, investigation of the effects of cryogenic (LN2) cooling on the mechanical behavior and characteristic of these composite materials is getting a popular and important issue. In this sense, this study aims to examine the buckling behaviors of adhesively bonded beam-produced cryogenically treated carbon fiber reinforced plastic (Cryo-CFRP), CFRP, steel, and aluminum. Therefore, a new finite element model was adopted to evaluate the buckling capacity of Cryo-CFRP composite material in the adhesively bonded beam. The model is a supported adhesive beam subject to two opposite-edge compressions until the material buckles. The elastic, homogeneous adhesive was used in the assembly. Finite element models for the adhesively bonded beam having four different adherents (CRFP, Cryo-CFRP, steel, and aluminum) were established by ANSYS® software. The critical buckling loads of the adhesively bonded beam were predicted, and their mode shapes were presented for the first six modes. The effects of the usage of Cryo-CFRP on the critical buckling load were investigated. Among the adherents’ materials, the highest critical buckling load was determined for Cryo-CFRP/Steel adhesively bonded beam as 23.6 N. This value was obtained as 22.3 N for CFRP/Steel adherent samples. Thus, the critical buckling load was increased by 5.6 % when one adherent steel was constant and the other adherent material changed from CFRP to Cryo-CFRP. Also, the critical buckling load increased by 3.7 % when using a cryogenically treated Cryo-CFRP/Aluminum couple instead of a CFRP/Aluminum couple in the sandwich beam. The findings demonstrated that the cryogenic treatment positively affects the buckling behavior in the adhesively bonded beam.

Procurement Issues in Indonesian Maintenance, Repair, and Overhaul (MRO)

Aviation Industry has grown tremendously in Indonesia over the last two-decade. Deregulation in early 2000 resulted in spectacular growth in the number of aircraft and passengers (Fahriza & Willey, 2018). This phenomenon caused Indonesia to become the most prominent airline market in Southeast Asia. Figure 1.1 shows in 2018, there are 1559 aircraft were registered in Indonesia, and the number slightly changed during the pandemic to 1497 aircraft remain registered. This industry has just recovered, and Indonesian Airlines will continue receiving orders for new aircraft, increasing the numerous aircraft in Indonesia. This fact is supported by the statement of the Lion Air General Director, Edward Sirait, that Lion Air, Indonesia's largest The aforesaid papers mainly address the problem either from an inventory point of view based on the past spare parts usage to forecast the future demand or from a maintenance point of view to find an optimal order quantity and PM interval considering the correlation between flying hours and failures. To the author's best knowledge, limited research handles failure-based procurement inventory management which is very common in practice. On the one hand, when demand is triggered by failures, the demand forecast result based on past consumption may not be accurate. For example, past low demand in many periods may indicate significant aircraft parts aging and therefore high impending demands, but the traditional replenishment system will scale back replenishment which is counter to the actual requirement. On the other hand, PM inventory management is different from failure-based inventory management. As the spare parts demand is uncertain, and some- times the part delivery time may be very long, it could lead to significant loss if a critical part fails but there is no spare to replace it. (Gu et al., 2015) Keywords: MRO, Procurement, Indonesia

Determination of the Shot Fractional Composition During Shock Hardening Methods Using Technical Vision

The main purpose of the article is development of method for determining the fractional composition of the shots during shot peen hardening. During peen hardening of aluminum aviation parts the deformation of spatial form of the part usually occurs due to the non-homogeneous compaction of their structural elements. Form straightening of hardened parts by methods of elastic-plastic deformation is unacceptable, as there may be a loss of hardening effect. A promising task is to predict the hardening process using finite element modeling, which will allow the use of preventive deformation in order to minimize the deformation. Also, finite element modeling of the shot hardening process can significantly reduce the costs associated with the manufacture of structurally similar samples when determining the predicted deformations of hardened parts. The proposed method allows the use of technical vision in the preparation of input data when modeling the hardening process, as well as to control the quality of the shot used in the hardening process. The study was carried out using machine vision equipment of the National Instruments company. This equipment is based on the NI Smart Camera, which allows interactive collection of video images and their processing. The measured sample is 500 grams of shot used in production for hardening aircraft parts. The proposed method consists obtaining of data array of the fractional composition using machine vision and analysis in a prepared C++ software module that displays the obtained data in the form of an Excel table. The obtained results were also verified using the equipment made on a 3D printer, which showed that the relative deviations of the calculated model data from experimental studies do not exceed 10%, which indicates sufficient accuracy of the developed methodology.

Features of ion nitriding technology multicriteria optimization

In this work, the technology of 30HGSA steel ion nitriding was optimized in terms of tribotechnical characteristics – wear intensity and friction coefficient. When choosing controlled factors, the influence of all existing groups of factors that can affect the process of ion nitriding is taken into account: structural, technological and operational. Friction and wear tests were carried out under conditions that are as close as possible to the actual operating conditions of aircraft parts made of 30HGSA steel. As a result of experiments on friction and wear, tribotechnical characteristics of coatings were obtained depending on structural, technological and operational factors, respectively, to the matrix. The conducted studies showed the presence of three clearly defined zones in the dependences of wear intensity and friction coefficient on specific load at different sliding speeds and technological parameters of ion nitriding: run-in zones, uniform and catastrophic wear. The nature of samples dependences hardened by ion nitriding and heat-treated samples is similar and coincides with modern views on the laws of friction and wear processes. Analysis of tribotechnical characteristics showed the effectiveness of ion nitriding technology in comparison with traditional heat treatment. The optimal processing modes for the studied steel and triboconjugation have been established

Mechanical Characterization of Balsa Wood, Depron and Glass Fiber Composite for Aircraft Floor Panel and Luggage Compartment

The present materials record greatest usage of composites in automotive and aircraft industry. Parts of aircrafts are experimenting materials with respect to mechanical properties which should have more strength to weight ratio, resistance to buckling, high ultimate tensile strength, high resistance to vibration, and high fatigue. Composite materials filled the requirement for making high strength to weight ratio components. This paper aims to study the Mechanical Characterization of Balsa wood, Depron and Glass fiber. The fabricated composites is highly suitable for manufacturing of floors in aircrafts instead of carbon fiber reinforced epoxy composite. Also, it will be used for luggage compartment. Using Hand Layup process specimens were prepared and the tensile test, Temperature Test and Flexures test has been performed as per ASTM standard. We observed 12%-17% more bending strength from this experiment which suits well for aircraft floor panel.

A bibliometric analysis of cold spray coating process using VOSviewer

Cold spray coating is an Additive Manufacturing technology that is accustomed to amend surfaces of the substrate and improves many benefits in material engineering applications. This is a high-velocity solid state spray technique that uses temperatures sufficiently below the melting point of the products to preserve their chemical and physical properties. A thorough examination of 387 documents found in the Scopus database from 1999 to 2022 was carried out. In this study, we analyzed cold spray research and its evolution using a bibliometric approach and scientometric evaluation using the free tool VOSviewer to create bibliometric maps. These maps help in understanding the overall development, research trends, and major gaps identified in the literature. We identified prolific authors, their work, contribution and collaboration in the field of cold spray research, important publishing sources, and keyword assessment based on co-occurrence using density visualization maps that help in understanding research gaps. Despite several successful experiments, cold spray on brittle materials has received little attention, because of its high specific strength, fatigue resistance, biocompatibility and corrosion resistance, the cold spray has potential applications in aircraft parts, medical implant materials and protective coatings highlighting the need for research in this area.

Study of hardening and structure of maraging powder steel grade PS-H18K9M5TR (18%Ni+9%Co+5%Mo+1%Ti+1%Re+66%Fe)

Relevance. High-strength steels are increasingly in demand in modern industry for various applications. Maraging steels are the primary material in the manufacture of most aircraft parts as well as machine-building components. This type is low-carbon and is rich in nickel, which forms martensite when cooled as well as demonstrates properties such as high hardness, wear resistance, etc. The hardening process is the main factor affecting the functional properties of maraging steel. At certain temperatures, austenite has the ability to transform into various kinds of phases. However, the shortcoming that lies in the presence of some impurities limits the established types of improvement technologies, leading to the search for innovative methods to improve the characteristics of steel without losing any of the desired properties. Good qualities appear in maraging steels mainly after treatment with a solution at a temperature of about 1000℃ and during aging at a temperature of about 490℃. Purpose. Thus, the purpose of this research paper is to analyze the structure of maraging steel powders and study the thermal effect on its properties. Methodology. In this paper, powder steel was pressed by spark plasma sintering technology at a pressure of 60 MPa to a powder compact and heated at a temperature of 1100℃ for 180 s at a rate of 20℃/s, after which the samples underwent phase and elemental analysis, their hardness was measured, the value of which amounted to about 60 HRC. Results. The results of this scientific research demonstrate the presence of a variety of precipitates. The presence of impurities such as Co, Ti, and Re led to an improvement in strength due to martensitic phase transformation and precipitation hardening, as well as slowed down the diffusion process. Conclusions. In addition, tasks for further research on the issue of manufacturing maraging steels by the additive manufacturing method were identified. This technology enables obtaining strong maraging steels based on a powder mixture with the required characteristics

Heat and Mass Transfer on the Side Surfaces of Blunt Nose Parts of Hypersonic Aircraft

Heat and Mass Transfer on the Side Surfaces of Blunt Nose Parts of Hypersonic Aircraft

Application of Augmented Spread Spectrum Time Domain Reflectometry for Detection and Localization of Soft Faults on a Coaxial Cable

Aviation cables are an essential part of aircraft, which transmits signals and power. Aviation cable faults often occur due to drastic changes in temperature and humidity and the effects of vibration. Obvious cable faults, such as open circuits and short circuits, can be detected during maintenance. However, some soft faults like the loose connection of the connector, damage of the insulation layer, and improper cable bending radius cannot be detected. Spread spectrum time domain reflectometry (SSTDR) is a diagnostic method for cable faults; however, the amplitude of the reflected signal is low when the soft fault occurs. SSTDR is only sensitive to apparent faults, but it is insufficient to detect soft faults. This article proposes an aviation cable fault detection and location method, augmented spread spectrum time domain reflectometry (ASSTDR), to detect soft faults effectively. First, the SSTDR results are decomposed into some intrinsic mode functions (IMFs) using the improved variational mode decomposition and selects the IMF with the highest kurtosis to analyze. Second, short-time Fourier transform (STFT) is applied to deal with the selected IMF to enhance the amplitude characteristics. Then, reassign spectrogram is computed to improve the resolution of STFT time-frequency distribution images to locate the location of soft faults. Finally, the effectiveness of ASSTDR is verified by experiments with different fault types and fault degrees. The comparative experiments demonstrate that the method can accurately detect soft faults.

Detailed simulations of an aircraft fuel system by means of Simulink

The fuel system is one of the most important and complex parts of aircraft, being tasked with suppling the correct quantity of fuel to the aircraft engine during all operative conditions, from flight to ground operation. It must operate efficiently in any condition to guarantee safety and reliability. A fuel system for kerosene-based fuels (i.e., jet fuels) is a combination of hydraulic components, namely, tanks, pumps, bypass valves, safety valves, servovalves. The aim of this paper is to provide an accurate simulation model of an entire fuel system for gas turbine (turboprop and turbofan) engines, which can be used by manufacturers and researchers to evaluate the performance of the fuel system under different operating conditions for given components or to select the geometries of the components to obtain specific performance levels. The numerical code is developed in the Simulink environment, which is a software package widely used in industry. A detailed description of the model is provided in this paper, and results under specific operating conditions are shown and discussed. The power consumption of the system is assessed as well, with indication of the main sources of losses, which will be useful for current EU projects aimed at reducing the power consumption of aircraft.

Con Air: exploring the trade in counterfeit and unapproved aircraft parts

AbstractCounterfeit aircraft parts are among the most well-known counterfeits and pose a significant risk to public safety. It is estimated that as much as 10% of the legal market for aircraft parts are counterfeits and the presence of these parts on commercial aircraft are more commonplace than many people realise. Yet, criminological research on this pressing issue is remarkably scarce. Informed by accounts from specialised and highly knowledgeable actors embedded in the aviation industry, this paper aims to explore how counterfeit and unapproved parts enter the legitimate supply chain and what factors drive or motivate their circulation and use.

Sensing Design, Trajectory Planning, and Motion Control of a Cable-Driven Redundant Manipulator Composed of Quaternion Joints

Abstract A cable-driven redundant manipulator (CDRM) composed of quaternion joints has important applications in confined space, including minimal invasive surgery, aircraft parts assembly, environment exploring, and so on. Benefitting from the unique joint characteristic and cable routing, it can achieve a larger workspace with fewer driving modules than traditional universal joint CDRM. However, the positioning accuracy of the end-effector suffers from the lack of joint feedback information and the delay effect of cable driving mechanisms. In this paper, we propose an equivalent sensing method and design corresponding sensors for each quaternion joint, and develop a high precision controller for the whole manipulator. The motion sensing of the quaternion joint is achieved by establishing the kinematics between its bending pose and middle limb joints. To realize real-time estimation, the fitting technique is adopted. To improve the efficiency of path planning, a geometric iterative inverse kinematics approach for quaternion joint CDRM is proposed based on the isosceles trapezoid simplified model. Furthermore, an accurate controller is designed by combining the feedforward gain and modified PID feedback control. Finally, an 8DOF CDRM prototype with four quaternion joints is developed, and the experiment verifies the effectiveness of the proposed method.