scholarly journals Economic and Environmental Sustainability for Aircrafts Service Life

2020 ◽  
Vol 12 (23) ◽  
pp. 10120
Author(s):  
Marcello Fera ◽  
Raffaele Abbate ◽  
Mario Caterino ◽  
Pasquale Manco ◽  
Roberto Macchiaroli ◽  
...  

Aircrafts are responsible for a significant environmental impact mainly due to the air pollution caused by their motors. The use of composite materials for their production is a way to significantly reduce the weight of the structures and to maximise the ratio between the payload weight and the gasoline consumption. Moreover, the design phase has to consider the cost of different operations performed during the aircraft service life. During the entire life cycle, one of the main costs is the maintenance one. In the current literature, there is a lack of knowledge of methods for maintenance cost estimation in the aircraft industry; moreover, very few environmental assessment methods have been developed. Thus, the aim of this paper is to define a new method to support the aircraft design process; both the environmental and the economic dimensions have been included with the purpose of assessing the aircraft sustainability during its service life. A green index has been identified mixing the maintenance cost and an environmental parameter with the aim of identifying the greenest solution. A final practical application shows the feasibility and the simple application of the proposed approach.

2021 ◽  
Vol 274 ◽  
pp. 11007
Author(s):  
Rustem Sakhapov ◽  
Alexander Mudrov ◽  
Mukhammat Gatiyatullin ◽  
Adil Kadyrov

Spatial mechanisms of various types are widely used in technology. Most of them have one or two ball pairs, the presence of which reduces the service life of the device (ball pairs are difficult to protect from dust and dirt. They are more difficult to manufacture and have a lower loadbearing capacity than rotational pairs). Replacing ball pairs with rotary ones, designed, for example, with standard bearings, will greatly simplify and reduce the cost of their manufacturing technology, increase the service life and expand the area of practical application. The difficulty and complexity of creating fivelink and six-link mechanisms and devices with a special structure lies in the fact that the usual combination of links fails to achieve their operability (with rotatable links). Theoretically, this mechanism has been studied by many foreign and Russian scientists. However, Kazan scientists were the first to form and put into practice spatial mechanisms with rotational pairs. The paper presents synthesis and analysis of the spatial five-link mechanism by the degree of irregularity, axial displacement, elliptical law and by the reproduction of a linear function. The mechanism provides intensification and energy saving of mixing, separation, torque transmission of various drives.


Aerospace ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 87 ◽  
Author(s):  
Ting Dong ◽  
Nam Kim

Although structural health monitoring (SHM) technologies using sensors have dramatically been developed recently, their capability should be evaluated from the perspective of the maintenance industry. As a first step toward utilizing sensors, the objective of the paper is to investigate the possibility of using sensors for inspecting the entire fuselage during C-check. First, we reviewed various sensors for their detection range, detectable damage size, and installed weight, which revealed that the piezoelectric wafer active sensor (PWAS) is the most promising sensor for aircraft SHM. Second, we performed a case study of inspecting the fuselage of Boeing-737NG using PWAS. To maintain the same detecting capability of manual inspection in C-check, we estimated the total number of sensors required. It turned out that utilizing sensors can reduce the maintenance downtime and thus, maintenance cost. However, even with a very conservative estimate, the lifetime cost was significantly increased due to the weight of sensor systems. The cost due to the weight increase was an order of magnitude higher than the cost saved by using SHM. We found that a large number of sensors were required to detect damage at unknown locations, which was the main cause of the weight increase. We concluded that to make SHM cost-effective, it would be necessary either to improve the current sensor technologies so that a less number of sensors are used or to modify the aircraft design concept for SHM.


2016 ◽  
Vol 693 ◽  
pp. 1585-1590
Author(s):  
Yi Zhuo Guo ◽  
Xian Guo Yan ◽  
Shu Juan Li ◽  
Hong Guo

Many studies have proved the service life of cutter can be prolonged by electrolytic strengthening. Based on the theory of electrolytic strengthening technology, this paper introduced and developed prototype equipment for strengthening cutting edge of rotary cutter and put forward a calculation method of total electric quantity consumption during the electrolysis suitable for microcontroller. The M8 high-speed steel tap is taken as a strengthening example. After finished the strengthening process that it clearly see the results of the surface of tap was obviously polished by observing the micrograph. This equipment improves the reliability of electrolytic strengthening and the cost is relatively cheap.


2021 ◽  
Vol 13 (4) ◽  
pp. 1772
Author(s):  
Bimpe Alabi ◽  
Julius Fapohunda

Adequate provision of affordable human settlements is a huge challenge in South Africa since its independence. This paper investigates the effects of the cost increase of building materials on affordable housing delivery in South Africa. With potential solutions for cost minimisation of building materials, with the aim of achieving affordable housing delivery in South Africa are provided. This study uses a sequential mixed methods approach, wherein surveys were conducted among the construction professionals (project managers, site managers architects, site engineers, quantity surveyors, contractors, building materials suppliers, and government workers) in the construction industry within Cape Town, South Africa, who were considered as the research participants. The qualitative data obtained from the survey exercise were analysed using content analysis, while the quantitative data were analysed using a descriptive statistical technique on SPSS. The findings attained show fluctuation in construction cost and a rise in maintenance cost (caused by poor workmanship) as significant effects in the cost increase of building materials for affordable housing delivery. Adequate application of the recommendations given in this study will minimise the effects of high cost of building materials and enhance affordable housing delivery. Appropriate handling of the findings given in this study will reduce the effects of the high cost of building materials and augment timely delivery of affordable housing and stakeholders’ satisfaction.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2146
Author(s):  
Karunesh Kant ◽  
Karthik Nithyanandam ◽  
Ranga Pitchumani

This paper analyzes a novel, cost-effective planar waveguide solar concentrator design that is inspired by cellular hexagonal structures in nature with the benefits of facile installation and low operation and maintenance cost. A coupled thermal and optical analysis of solar irradiation through an ideal hexagonal waveguide concentrator integrated with a linear receiver is presented, along with a cost analysis methodology, to establish the upper limit of performance. The techno-economic model, coupled with numerical optimization, is used to determine designs that maximized power density and minimized the cost of heat in the temperature range of 100–250 °C, which constitutes more than half of the industrial process heat demand. Depending on the incident solar irradiation and the application temperature, the cost of heat for the optimal design configuration ranged between 0.1–0.27 $/W and 0.075–0.18 $/W for waveguide made of ZK7 glass and polycarbonate, respectively. A techno-economic analysis showed the potential of the technology to achieve cost as low as 80 $/m2 and 61 $/m2 for waveguide made of ZK7 glass and polycarbonate material, respectively, which is less than half the cost of state-of-the-art parabolic trough concentrators. Overall, the hexagonal waveguide solar concentrator technology shows immense potential for decarbonizing the industrial process heat and thermal desalination sectors.


2021 ◽  
Vol 14 ◽  
pp. 117862212098872
Author(s):  
María Fernández-Raga ◽  
Iván García-Díez ◽  
Julian Campo ◽  
Julio Viejo ◽  
Covadonga Palencia

Water is one of the most important erosive agents in roadside hillslopes. When these are built with ineffective drainage systems, erosion occurs, reducing road’s service life. However, these systems are not receiving the appropriate importance, given their strategic value. Therefore, a new drainage system called ‘branched’ is proposed in this study. Its technical and economic feasibility is compared with those of the traditional system, which consists of drainages with lines that follow maximum hillslope, to assess differences in relation to erosion, construction and maintenance costs, and service life. Different parameters were analysed, such as the average velocity of water (mm−1) running through the channels, its average specific energy (kJ), and its drag force (N). A scale model was constructed and used to test these factors before implementing it in natural terrain for testing it under field conditions. According to the theoretical and measured results, these factors were lower in the branched drainage than in the traditional one (from 24% to 34% in speed, from 37% to 60% in energy, and from 51% to 73% in force). The service life of hillslopes with a branched system of up to 0.5 m high and 1:2 grade is significantly longer than in those with a traditional drainage. Although the initial economic expense for the construction of the branched system is higher (€3534/m3 as opposed to €2930/m3 for the traditional one), its maintenance cost will be lower than the traditional one (€1230/m3 per year for the branched one as opposed to €1332/m3 per year for the traditional one). Consequently, under our experimental conditions, the proposed drainage will be profitable from the eighth year of construction, saving on the road maintenance in the following 15 years of service life.


2021 ◽  
Vol 11 (16) ◽  
pp. 7246
Author(s):  
Julius Moritz Berges ◽  
Georg Jacobs ◽  
Sebastian Stein ◽  
Jonathan Sprehe

Locally load-optimized fiber-based composites, the so-called tailored textiles (TT), offer the potential to reduce weight and cost compared to conventional fiber-reinforced plastics (FRP). However, the design of TT has a higher complexity compared to FRP. Current approaches, focusing on solving this complexity for multiple objectives (cost, weight, stiffness), require great effort and calculation time, which makes them unsuitable for serial applications. Therefore, in this paper, an approach for the efficient creation of simplified TT concept designs is presented. By combining simplified models for structural design and cost estimation, the most promising concepts, regarding the cost, weight, and stiffness of TT parts, can be identified. By performing a parameter study, the cost, weight, and stiffness optima of a sample part compared to a conventional FRP component can be determined. The cost and weight were reduced by 30% for the same stiffness. Applying this approach at an early stage of product development reduces the initial complexity of the subsequent detailed engineering design, e.g., by applying methods from the state of the art.


2021 ◽  
Vol 48 (4) ◽  
pp. 3-3
Author(s):  
Ingo Weber

Blockchain is a novel distributed ledger technology. Through its features and smart contract capabilities, a wide range of application areas opened up for blockchain-based innovation [5]. In order to analyse how concrete blockchain systems as well as blockchain applications are used, data must be extracted from these systems. Due to various complexities inherent in blockchain, the question how to interpret such data is non-trivial. Such interpretation should often be shared among parties, e.g., if they collaborate via a blockchain. To this end, we devised an approach codify the interpretation of blockchain data, to extract data from blockchains accordingly, and to output it in suitable formats [1, 2]. This work will be the main topic of the keynote. In addition, application developers and users of blockchain applications may want to estimate the cost of using or operating a blockchain application. In the keynote, I will also discuss our cost estimation method [3, 4]. This method was designed for the Ethereum blockchain platform, where cost also relates to transaction complexity, and therefore also to system throughput.


2012 ◽  
Vol 496 ◽  
pp. 50-53
Author(s):  
Zhan Shun Yin ◽  
Yong Wei Han ◽  
Xi Chun Cai

Based on the CAE analysis. The dual variable gear shaft of the transmission for domestic ZL50 wheel loader was redesigned and the processing technology was optimized. The problem of the hardness of the spline which connects the dual variable gear shaft and the working hydraulic pump can not meet the requirements after heat treatment caused by unreasonable design was solved. The problem of the low geometric tolerance and early wear of the spline were solved. After practical application, the market feedback shows that the failure rate, service life and reliability greatly of new designed shaft were enhanced


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