scholarly journals АНАЛІЗ КОНСТРУКТИВНИХ ОСОБЛИВОСТЕЙ З'ЄДНАНЬ СИЛОВИХ ЕЛЕМЕНТІВ КРИЛА ЛІТАКІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

Author(s):  
Дмитрий Юрьевич Жиряков

Ensuring the fatigue life of the aircraft structure is a requirement for flight safety, and for a cost-effective aircraft. A plane with a long lifetime can perform more flights, reduce routine maintenance costs and increase airline profits. Market trends in the aviation industry show the interest of airlines in long life aircraft. Structural elements of the wing are joined by fasteners. The wing structure fatigue is determined by the endurance of regular zones. Regular zones include longitudinal, transverse joints. The fatigue life of the wing irregular zones should be no less than the fatigue life of the regular zone. The article provides an analysis of the design features of the wing structural element joints performing short and medium flights, ANTONOV and Boeing, which have reached a high level in this field of research. Structural schemes of the wings, location and execution of the joints of the wing structural parts using facilities that improve take-off and landing characteristics (such as ailerons, flaps, slats and spoilers) are analyzed. The types, diameters and materials of fasteners that vary within the wing limits are considered. Attention was focused on such important indicators as the edge tolerance, distance between the fasteners (spacing), wing and fastener construction materials. The wing is made of a prefabricated structure, to ensure safety requirements for permissible destruction. In turn, this leads to an increase in the amount of fasteners. Since fatigue life is affected not only by the kinds of materials, parameters of fasteners, rated stresses, but also the degree of load transferring between parts. The constructive execution of the longitudinal and transverse connections of the load-bearing elements was analyzed to further study the degree of load transfer in a difficult - stressed state. The materials of the article provide an opportunity for further in-depth research on the general and local stress-strain state of the wing.

2014 ◽  
Vol 891-892 ◽  
pp. 69-74 ◽  
Author(s):  
Pud S. Baburamani ◽  
Rob Ogden ◽  
Qian Chu Liu ◽  
P. Khan Sharp

Fastener holes have a high stress concentration at the edge of the hole and are primary sources of fatigue crack initiation, resulting in widespread fatigue damage leading to fatigue failures in airframe structures. The split-sleeve cold expansion (SsCx) technology is a simple and cost-effective way to improve the fatigue resistance of fastener holes by the introduction of compressive residual stresses around the holes. An investigation was carried out by DSTO to quantify the effectiveness of this technology, in terms of fatigue life improvement factors on a typical airframe aluminium alloy. Open hole (zero load transfer) coupons were tested to failure in non-cold expanded and cold expanded conditions. Coupons were also pre-cracked to specified crack lengths at the open hole, and cold expanded or left non-cold expanded, and tested to failure. This paper will present the results of the initial phases of the experimental program, involving constant amplitude fatigue loading of open hole coupons with and without cracks. The fatigue life improvement achieved by the use of hole cold expansion technology will be presented.


GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 206-212
Author(s):  
Dr. D. Shoba ◽  
Dr. G. Suganthi

Employees and employers are facing issues in work life balance. It has become a difficult domain now, because the work needs have increased due to an increase in work pressure and complexities in handling the technology. As there are drastic changes in the rules and regulations in the work scenario of the aviation industry, it makes work life balance of employees difficult and set more hurdles. Hence there are many distractions and imbalances in the life of women employees in the aviation industry working across all levels. This work pressure is creating high level of hurdles in maintaining a harmonious job and family life, especially for female aviation employees. Data is collected from 50 female crew members working at Cochin International Airport. The objective of this study is to analyze the work life balance of working females of Cochin International Airport and its influence on their personal and specialized lives. The result of the study shows that the management should frame certain policies which will help employees to have the balance among their personal and expert lives.


2014 ◽  
Vol 598 ◽  
pp. 141-146
Author(s):  
Adam Lipski ◽  
Zbigniew Lis

The aim of this paper is to assess the impact of the rivet hole sizing process on the fatigue life based on the example of the structural connections characteristic for riveted joints used in aviation industry. Test specimens reflected the structural connection consisting in a riveted lap joint of an airplane plating stiffened with a T-bar. Connected plates and the T-bar are made of D16CzATW aluminum alloy. 3 mm diameter oval head solid rivets for aviation-related purposes were made of PA24 aluminum. During fatigue tests, individual specimens with non-sized holes and with sized holes were subjected to uniaxial, one-sided, fixed-amplitude loading (R = 0). It can be concluded from the fatigue life comparison that introduction of an additional operation in the riveting process, i.e. the hole sizing, results in significant, about two-fold increase of the fatigue life of the riveted structural connection, even at slight sizing degree. The difference of the specimen damage nature was observed between specimens with sized and non-sized holes.


2000 ◽  
Vol 122 (4) ◽  
pp. 450-459 ◽  
Author(s):  
C. W. Wang ◽  
L. Berhan ◽  
A. M. Sastry

Applications for porous fibrous materials range from electrochemical substrates to web reinforcement in polymeric composite materials. The details of local load transfer are studied in a class of cost-effective, stochastic fibrous networks used in battery applications, which form the substrate for a composite electrode. The connectivity of these materials is quantitatively related to modulus and strength, and detailed results of different simulations approaches in approximating material construction are discussed. In Part I, we discuss microscale assumptions, including beam type, nodal connections and equivalence of models to more physically realistic models. Simulation of large networks is computationally intensive, and show low-strain, nonlinear behavior even when comprised of elastic elements when failure criteria (here, strength-of-materials) are applied to produce sequential rupture of beams and nodes. Strategies for effective simulation of these materials requires detailed analysis of the simplest assumptions which can be made at the microscale which produce acceptably realistic response. We show that simple Euler-Bernoulli beam elements can be used to effectively model such materials, even when segment lengths in a network are very small. Moreover, connections comprised of simple torsion springs produce realistic behavior, and can mimic more realistic junctures by adaptation of the linear solution to a compliant zone model. In Part II of this work, we demonstrate the effect of model selection on full network behavior, and also discuss issues of connectivity at the scale of the porous material rather than element-by-element. This work points toward use of simple constructions to model complex behavior, and may ultimately provide insight into modeling of a large class of porous materials. [S0094-4289(00)01704-7]


Author(s):  
M. Arun ◽  
K. Baskar ◽  
B.S. Geethapriya ◽  
M. Jayabarathi ◽  
R. Angayarkkani

2016 ◽  
Author(s):  
Iain Lunney

ABSTRACT In a cost-sensitive market driven by depressed commodity prices, significant capital challenges exist for operators interested in pursuing exploration activities in remote environments to define their producible reserves. This paper explores the organizational and operational model developed by a service company over several remote area mobilizations; this model resulted in an optimized low-cost service delivery model characterized by top quartile operational key performance indicators (KPIs). The model centralizes critical functions of an operational organization into discrete service units that are located near the operational location or that provide remote assistance with communication and reporting lines in place to function effectively. Top quartile operational performance and tool availability is a result of placing a remote repair and maintenance facility that includes containerized specialty modules near the operational area. The upfront bottomhole assembly engineering, 24/7 monitoring, and proactive feedback of logged data, drillstring dynamics, and wellbore hydraulics are performed by a core team of subject matter experts in their respective disciplines from an established centralized operating center. The operational KPIs over the course of the six well exploration campaign provided substantial evidence to support the reliability of the model and the high level of experience used in both the remote maintenance facility and the operations center support team.


Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1196 ◽  
Author(s):  
Seulah Lee ◽  
Babar Jamil ◽  
Sunhong Kim ◽  
Youngjin Choi

Myoelectric prostheses assist users to live their daily lives. However, the majority of users are primarily confined to forearm amputees because the surface electromyography (sEMG) that understands the motion intents should be acquired from a residual limb for control of the myoelectric prosthesis. This study proposes a novel fabric vest socket that includes embroidered electrodes suitable for a high-level upper amputee, especially for shoulder disarticulation. The fabric vest socket consists of rigid support and a fabric vest with embroidered electrodes. Several experiments were conducted to verify the practicality of the developed vest socket with embroidered electrodes. The sEMG signals were measured using commercial Ag/AgCl electrodes for a comparison to verify the performance of the embroidered electrodes in terms of signal amplitudes, the skin-electrode impedance, and signal-to-noise ratio (SNR). These results showed that the embroidered electrodes were as effective as the commercial electrodes. Then, posture classification was carried out by able-bodied subjects for the usability of the developed vest socket. The average classification accuracy for each subject reached 97.92%, and for all the subjects it was 93.2%. In other words, the fabric vest socket with the embroidered electrodes could measure sEMG signals with high accuracy. Therefore, it is expected that it can be readily worn by high-level amputees to control their myoelectric prostheses, as well as it is cost effective for fabrication as compared with the traditional socket.


Author(s):  
Ljudmila Neshchadym ◽  
Svetlana Тymchuk

The article monitors and analyzes the main strategies for the development of hotel and restaurant enterprises and, accordingly, increase their efficiency and competitiveness; the process of organization and economic planning of hotel and restaurant enterprises has been improved. It is investigated that the enterprises of hotel and restaurant industry of Ukraine partially provide the necessary quality indicators for the provided services, and this is the reason for the insufficient level of competitiveness of services in the domestic market and in European countries. An urgent problem of planning and organizing the activities of hotel and restaurant enterprises is the use of innovative strategies and areas of long-term development to increase the level of competitiveness and quality of services provided. This will intensify innovation processes in Ukraine in the field of services. Innovative strategies and promising areas of development of hotel and restaurant enterprises are extremely important in the management of hotel and restaurant complexes. Innovative strategies in the hotel and restaurant industry are cost-effective and feasible provided a high level of profitability, improving the service process, expanding the range of services, reducing costs, increasing competitiveness, improve and optimize the work of all hotel or restaurant services. The application of innovative strategies in the process of hotel and restaurant enterprises allows them to compete in the field of service. In conditions of fierce competition and rapidly changing market conditions, it is very important not only to focus on the internal state of affairs of the enterprise, but also to develop a long-term strategy. Economic activity requires constant innovation. All services offered by hotel and restaurant enterprises must be introduced in modern innovative ways. This is the basis for successful business, maintaining a consistently high level of competitiveness and improving the quality of service. The selection of the optimal innovation strategy for a hotel or restaurant company is carried out by its management based on the analysis of key factors that characterize its condition and the state of the product portfolio.


F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 20
Author(s):  
Christopher T Noto ◽  
Suleman Mazhar ◽  
James Gnadt ◽  
Jagmeet S Kanwal

A major problem facing behavioral neuroscientists is a lack of unified, vendor-distributed data acquisition systems that allow stimulus presentation and behavioral monitoring while recording neural activity. Numerous systems perform one of these tasks well independently, but to our knowledge, a useful package with a straightforward user interface does not exist. Here we describe the development of a flexible, script-based user interface that enables customization for real-time stimulus presentation, behavioral monitoring and data acquisition. The experimental design can also incorporate neural microstimulation paradigms. We used this interface to deliver multimodal, auditory and visual (images or video) stimuli to a nonhuman primate and acquire single-unit data. Our design is cost-effective and works well with commercially available hardware and software. Our design incorporates a script, providing high-level control of data acquisition via a sequencer running on a digital signal processor to enable behaviorally triggered control of the presentation of visual and auditory stimuli. Our experiments were conducted in combination with eye-tracking hardware. The script, however, is designed to be broadly useful to neuroscientists who may want to deliver stimuli of different modalities using any animal model.


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