Prospects for the Implementation of New Materials and Technologies in the Aerospace Industry

This article considers the main materials used to make aircraft, both fuselage and engines. First, the problems that force developers to introduce new materials in aircraft production are identified. We then present features of the introduction of heat-resistant titanium alloys, ways of improving the mechanical properties of parts made of titanium alloys, and methods of manufacturing complex details. Other promising materials for the aviation industry, such as high-entropy alloys, quasicrystals, carbon-carbon materials, and nickel foam, are also considered.

Analyzing risks of occupational injuries in basic industries

Our research aim was to analyze occupational injuries in basic industries in Irkutsk region. Materials and methods. Occupational injuries (OI) in basic industries were analyzed using data from statistical reports issued in 2010–2019. To analyze OI in dynamics, we calculated relative values of OI and applied linear regression and Shewhart charts. Normalized intensity indicators method was used to reveal different probability of injuries in various industries as well as to predict OI risks. Results. Analysis of OI in dynamics indicates that there is a stable descending trend in a number of injuries. However, in spite of this apparent descending trend, OI values are stably by 1.3–3.0 times higher in some industries than on average in the region. The highest frequency coefficient (FC) for occupational injuries was detected in wood processing where it was equal to 5.35 [2.90–7.71] per 1,000 workers; the indicator varied within 1.00–2.93 per 1,000 workers in other industries. Shewhart chart for FC indicates that systems of occupational health and safety management are not efficient enough in all the analyzed industries since FC exceeds the upper limit in some years. We established that severity of occupational injuries tended to grow in wood processing (Cs = +3.23; 5.33 %), metallurgy (Cs = +0.94; 1.26 %), land transport (Cs = +2.42; 4.39 %), and aircraft production (Cs = +0.59; 1.68 %). The greatest number of fatal OI was detected in mining, construction, and agriculture as a share of fatal OI in the overall structure of occupational injuries amounted to 22.0 %, 19.2 %, and 11.7 % in these brunches accordingly. A probability that an injury becomes fatal is also the highest in them, 11.7, 9.0, and 6.0 accordingly. “Wood processing and production of wood articles”, “Aircraft production”, and “Construction” are among industries where risks of occupational injuries are the most probable.

Optimization of the installation sequence for the temporary fasteners in the aircraft industry

Riveting and bolting are common assembly methods in aircraft production. The fasteners are installed immediately after hole drilling and fix the relative tangential displacements of the parts, that took place. A proper fastener sequence installation is very important because a wrong one can lead to a “bubble-effect”, when gap between parts after fastening becomes larger in some areas rather than being reduced. This circumstance affects the quality of the final assembly. For that reason, the efficient methods for determination of fastening sequence taking into account the specifics of the assembly process are needed. The problem is complicated by several aspects. First of all, it is a combinatorial problem with uncertain input data. Secondly, the assembly quality evaluation demands the time-consuming computations of the stress-strain state of the fastened parts caused by sequential installation of fasteners. Most commonly used strategies (heuristic methods, approximation algorithms) require a large number of computational iterations what dramatically complicates the problem. The paper presents the efficient methods of fastener sequence optimization based on greedy strategy and the specifics of the assembly process. Verification of the results by comparison to commonly used installation strategies shows its quality excellence.

The Need for Ecosystem 4.0 to Support Maintenance 4.0: An Aviation Assembly Line Case

Manufacturing and assembling aircraft require hundreds of different machines for various process applications. The machines have different complexity and often different ages; however, they have to ensure a higher precision than other industrial fields. Recent technology advancement in maintenance approaches offers a wide range of opportunities to provide performance and availability. The paper discusses how the maintenance technologies applicable to the various machines need to be appropriately supported by a production environment, called “ecosystem”, that allows their integration within the process and their synergy with the operators. (1) A background analysis of the aircraft production environment is offered. (2) A possible framework for designing a proper ecosystem 4.0 for integrating maintenance activities with design solutions and data gathering is provided. (3) A case study based on the assembly line of specific aircraft is adopted for testing the validity of the framework. (4) Finally, a discussion highlights the critical points of the research, underlying future work.

A route to learning supersonic aerodynamics in atmospheric flights for engineering students based on a revision of Bloom’s taxonomy

According to Deloitte, the global aerospace industry in 2018 experienced a solid year with the demand of passengers and the strengthening of global military spending that continues to increase. Furthermore, it is expected to continue its growth trajectory in 2019 and the following years, led by the growing production of commercial aircraft and strong defense spending. The growth of aircraft production requires the designs to be supported by the knowledge and experience of qualified personnel. In the case of aerodynamic performance, it is evaluated according to the speed range considering incompressible or compressible flow for subsonic and supersonic speeds, respectively. Based on a revision of Bloom´s taxonomy this article proposes a route to learning supersonic aerodynamics for engineering students, considering and discussing the basic literature and technology used in this area of knowledge. The present work is divided into seven parts, beginning with the introduction which includes the main Fundamental concepts of the supersonic systems. The second part deals with Supersonic Aerodynamics Theory, relevant in this learning route; subsequently, the third and fourth part display a brief description of the Experimental supersonic aerodynamics and Computational Fluid Dynamics - CFD is made. Finally, is approached the Bloom´s taxonomy and a revision and is proposed a route to learn supersonic aerodynamics designed for engineering students.

ДОСЛІДЖЕННЯ ПИТАННЯ ВПРОВАДЖЕННЯ АДИТИВ-НИХ ТЕХНОЛОГІЙ В АВІАБУДІВНУ ГАЛУЗЬ

The article deals the issues of improving the quality, reducing time, cost of manufacturing domestic aircraft and reducing their weight by modernizing technological processes taking into account a wide range of functionalities for the use of additive technologies for the production of structural elements of aircraft from titanium alloys. The article provides is determined that titanium and its alloys, due to their unique chemical and mechanical characteristics, continue to be relevant and in demand metal used in the construction of modern aircraft. But traditional methods of manufacturing parts made of titanium are high cost and do not allow the use of this metal in large quantities. The solution proposed to this problem is the use of additive manufacturing technologies for the manufacture of aircraft structural elements from titanium. Data are given about of the use of titanium alloys in the aerospace, automotive, biomedical and chemical industries due to the excellent combination of strength, low density, as well as very high corrosion resistance and fatigue strength are given. The efficiency of using titanium alloys for the manufacture of structural elements of aircraft in terms of reducing the total weight of the aircraft and high reliability of the structure as a whole. The article provides descriptive information about additive technologies in mechanical engineering. The review of works of foreign scientists concerning research of differences in mechanical characteristics, microstructure and macrostructure of samples made by means of additive technologies is resulted, their advantages and lacks are noted. The list of advantages of additive technologies in mechanical engineering which cause economic efficiency from their use is resulted. Attention is drawn to the most common methods of additive production: substrate synthesis (PBF), direct energy and material supply (DED). It is given the tasks of research are defined and the decision of optimization of technology of manufacturing of elements of a design of aircraft. Research will further improve the technology of aircraft production.

Direct Femtosecond Laser Fabrication of Superhydrophobic Aluminum Alloy Surfaces with Anti-icing Properties

Ice formation is a serious issue in many fields, from energy to aerospace, compromising the devices’ efficiency and security. Superhydrophobicity has been demonstrated to be correlated to the anti-icing properties of surfaces. However, fabricating surfaces with robust water repellence properties also at subzero temperature is still a great challenge. In this work, femtosecond laser (fs-laser) texturing is exploited to produce superhydrophobic surfaces with anti-icing properties on Al2024, an aluminum alloy of great interest in cold environments, in particular for aircraft production. Our textured substrates present self-cleaning properties and robust water repellency at subzero temperatures. Moreover, outstanding anti-icing properties are achieved on the textured surfaces at −20 °C, with water droplets bouncing off the surface before freezing.