scholarly journals Design Approaches for Safety Increasing and Risk Decreasing for the Civil Aircraft’s Operation

Author(s):  
Dmytro Tiniakov

The safety and risks of civil aircraft operation depend on a lot of factors. One of them is the structural features of an aircraft. In aviation history, there are examples when “non-rational” design solution was the reason for crashes, but there are examples about successful civil aircraft that have “rational” structure and long operational time without critical incidents. So, how can a designer provide high safety of level and decrease incidents’ risks in time of a regular aircraft operation? This chapter partly can help to understand some reasons and approaches for providing “rational” aircraft structure. Design solutions can be divided into some groups by some common features and requirements. They are maintainability, serviceability, accessibility, labor effort decreasing, weather requirements, transportation, etc. All these groups depend on engineers’ structural solutions. They are interdependent and often contradictory. In other words, if one of the features will be better, another will be worse at the same time. And, a designer must remember all the time about this and try to find compromise between different requirements. The successful commercial aircraft is composed of a set of rational design solutions for these specific tasks.

2020 ◽  
Vol 30 (3) ◽  
pp. 464-479
Author(s):  
Mikhail V. Chugunov ◽  
Irina N. Polunina ◽  
Anton M. Pjanzin

Introduction. National Technology Initiatives (STI), designed to develop and implement High-Tech tools into engineering practice and based on the Industry 4.0 concept, require appropriate technical solutions for all phases of the product lifecycle from design to disposal. Implementation of the concept involves the formation of technological groups and markets in different directions in particular one of the emerging markets of STI is Auto.Net. At the same time, the product design stage is basic and should be implemented in a form ensuring the entire life cycle of the product on the principles of this concept. Materials and Methods.The article presents the methodology and results of designing an electric vehicle-tricycle in the integrated CAD/CAE systems. The design process is the development of digital parametric models of different types and levels on a top-down and bottom-up basis. The parametric properties of models provide the ability to develop design solutions efficiently, including design, analysis and optimization. The design solutions are developed in the CAD/CAE/CAM/PDM/PLM SolidWorks (Motion, Simulation) software. Results. The results of the study are rational design paths for the structures of the class under consideration in the SolidWorks software, as well as design solution of the electric tricycle-vehicle in the form of a system of integrated parametric models, including 3D models of parts and assemblies, models of solid-state mechanics, finite-element models for solving problems of mechanics of the deformed solid body in the form of linear and non-linear statics, linear dynamics, parametric optimization. Videos of the results are provided for illustrative purposes. Discussion and Conclusion. In the research, the design trajectory of the electric vehicletricycle based on correct formulation for the design problems and providing the rational choice of means, tools, and technologies from basic SolidWorks functionality is presented. The trajectory provides both an efficient solution to design problems and an assessment of the adequacy of the results obtained. In terms of the possible perspective of this work, it is necessary to specify the solution of optimization tasks according to various criteria of project efficiency and the development of an integrated (cyber-physical) model of electric vehicle-tricycle, which meets the requirements of digital twins. At the same time, bidirectional associative links between virtual and physical components of the integrated model will solve a number of additional problems: control of the accuracy of digital models, giving the digital model synergistic properties, planning of the trajectory and unmanned control on the principles of IoT (Internet of Things).


2021 ◽  
Author(s):  
Rohan V. Koodli ◽  
Boris Rudolfs ◽  
Hannah K. Wayment-Steele ◽  
Rhiju Das ◽  

AbstractThe rational design of RNA is becoming important for rapidly developing technologies in medicine and biochemistry. Recent work has led to the development of several RNA secondary structure design algorithms and corresponding benchmarks to evaluate their performance. However, the performance of these algorithms is linked to the nature of the underlying algorithms for predicting secondary structure from sequences. Here, we show that an online community of RNA design experts is capable of modifying an existing RNA secondary structure design benchmark (Eterna100) with minimal alterations to address changes in the folding engine used (Vienna 1.8 updated to Vienna 2.4). We tested this new Eterna100-V2 benchmark with five RNA design algorithms, and found that neural network-based methods exhibited reduced performance in the folding engine they were evaluated on in their respective papers. We investigated this discrepancy, and determined that structural features, previously classified as difficult, may be dependent on parameters inherent to the RNA energy function itself. These findings suggest that for optimal performance, future algorithms should focus on finding strategies capable of solving RNA secondary structure design benchmarks independently of the free energy benchmark used. Eterna100-V1 and Eterna100-V2 benchmarks and example solutions are freely available at https://github.com/eternagame/eterna100-benchmarking.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yingjie Yang ◽  
Yanhui Yu ◽  
Jing Li ◽  
Qingrong Chen ◽  
Yanlian Du ◽  
...  

AbstractThe investigation of highly effective, durable, and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is a prerequisite for the upcoming hydrogen energy society. To establish a new hydrogen energy system and gradually replace the traditional fossil-based energy, electrochemical water-splitting is considered the most promising, environmentally friendly, and efficient way to produce pure hydrogen. Compared with the commonly used platinum (Pt)-based catalysts, ruthenium (Ru) is expected to be a good alternative because of its similar hydrogen bonding energy, lower water decomposition barrier, and considerably lower price. Analyzing and revealing the HER mechanisms, as well as identifying a rational design of Ru-based HER catalysts with desirable activity and stability is indispensable. In this review, the research progress on HER electrocatalysts and the relevant describing parameters for HER performance are briefly introduced. Moreover, four major strategies to improve the performance of Ru-based electrocatalysts, including electronic effect modulation, support engineering, structure design, and maximum utilization (single atom) are discussed. Finally, the challenges, solutions and prospects are highlighted to prompt the practical applications of Ru-based electrocatalysts for HER.


2015 ◽  
Vol 809-810 ◽  
pp. 865-870
Author(s):  
Manuela Roxana Dijmărescu ◽  
Dragoș Iliescu ◽  
Marian Gheorghe

Various architectures exposing certain phases of the design process have been developed. A closer analysis of the presented timelines is leading more to postpone the design solution rather than advancing it in the early phases. This paper advances a new architecture for the design process with the main emphasize on the product functional design, based on functional-constructive knowledge stored in databases, and on the principle of selecting design solutions in an incipient phase and developing them during the further design process stages.


2014 ◽  
Vol 118 (1202) ◽  
pp. 383-398 ◽  
Author(s):  
Y. Ren ◽  
J. Xiang

AbstractTo improve the crashworthiness of civil aircraft, the design concept of energy absorption structure for civil aircraft is investigated. Two typical different design principles could be identified. The first category includes Helicopter and Light fixed-wing Aircraft (HLA), and Transport, Mid-size and Commuter type Aircraft (TMCA) are classified into the second group. Frame, strut and bottom structure are the three kinds of energy absorption structure for TMCA. The strut layout of conventional civil aircraft is studied and some energy absorption devices are adopted. High efficiency energy absorption structures such as the foam and sine-wave beam are employed as the bottom structure for both of HLA and LMCA. The finite element method is used to analyse and design energy absorption structure in aircraft crashworthiness problem. Results show that the crashworthiness of civil aircraft could be largely improved by using proper strut layout and excellent energy absorption device. The stiffness combination of frame and strut should be considered to get better global aircraft deformation. Supporting platform and failure model are the two core problems of bottom energy absorption structure design. Foam and sine-wave beam under the lifted frame could improve the crashworthiness of civil aircraft.


2021 ◽  
Vol 9 ◽  
Author(s):  
Shu Guo ◽  
Xiaoqi Chen ◽  
Yimeng Liu ◽  
Rui Kang ◽  
Tao Liu ◽  
...  

The brain network is one specific type of critical infrastructure networks, which supports the cognitive function of biological systems. With the importance of network reliability in system design, evaluation, operation, and maintenance, we use the percolation methods of network reliability on brain networks and study the network resistance to disturbances and relevant failure modes. In this paper, we compare the brain networks of different species, including cat, fly, human, mouse, and macaque. The differences in structural features reflect the requirements for varying levels of functional specialization and integration, which determine the reliability of brain networks. In the percolation process, we apply different forms of disturbances to the brain networks based on metrics that characterize the network structure. Our findings suggest that the brain networks are mostly reliable against random or k-core-based percolation with their structure design, yet becomes vulnerable under betweenness or degree-based percolation. Our results might be useful to identify and distinguish brain connectivity failures that have been shown to be related to brain disorders, as well as the reliability design of other technological networks.


2015 ◽  
Vol 6 (1) ◽  
pp. 13-35 ◽  
Author(s):  
Cheng-Hua Yang ◽  
Alex

Aviation safety has been affected greatly by technological improvements. A series of Ground Proximity Warning Systems (GPWSs) were developed to prevent accidents during Controlled Flight into Terrain (CFIT). This study analyzed the role of GPWS (or Enhanced GPWS, EGPWS) in flight safety history to determine how effective GPWS/EGPWS was in terms of preventing CFIT. The result showed a substantial increase in CFIT accidents due to the rapid growth of aviation development. This situation improved after the mandatory installation of GPWSs in commercial aircraft. However, the legal requirement did not apply to all general aviation. Most CFIT accidents have involved general aviation aircraft that do not have GPWS/EGPWS installed on board. Thus, the mandatory requirement should apply to all civil aircraft. CFIT accidents have also been reduced considerably in developed countries whereas they remain a major issue in developing countries.


2021 ◽  
Author(s):  
Masis Torosyan ◽  
Anthony Pollman ◽  
Anthony Gannon ◽  
Alejandro Hernandez

Abstract This paper presents the results of an alternatives analysis of gas-liquefaction methods used in liquid air energy storage (LAES) systems that incorporates two novel measures of performance (MOP) into the analysis: system complexity score and system density. The cryogenic methods typically considered for air, and used in this trade study, include Linde-Hampson, Claude, Heylandt, and cascade [1]. With these four options of air-liquefaction currently in use for a variety of purposes with ranging scales, there exists no standard selection process for the air-liquefaction method in LAES. This trade study provides fundamental design solutions for given stakeholder requirements, allowing for a pragmatic analysis of integration for future implementation of LAES systems. The intent of these design solutions is to be used in the earliest stage of consideration of a LAES implementation, helping stakeholders quickly narrow the focus of their design engineers to a specific liquefaction process. This will reduce the complexity of integration techniques and processes and streamline LAES into the energy-storage industry. The results of this study showed that with evenly weighted MOP the Heylandt method had the highest final weighted score (0.9), followed by Cascade (0.88), Claude (0.86), and Linde-Hampson (0.67). However, the results showed that the Cascade method was the most frequent design solution (8/11) from 11 variations of MOP weight distributions.


2020 ◽  
Vol 7 (1) ◽  
pp. 14 ◽  
Author(s):  
Sabari Nath Neerukonda ◽  
Upendra Katneni

Pattern recognition receptors (PRRs) are a class of immune sensors that play a critical role in detecting and responding to several conserved patterns of microorganisms. As such, they play a major role in the maintenance of immune homeostasis and anti-microbial defense. Fundamental knowledge pertaining to the discovery of PRR functions and their ligands continue to advance the understanding of immune system and disease resistance, which led to the rational design and/or application of various PRR ligands as vaccine adjuvants. In addition, the conserved nature of many PRRs throughout the animal kingdom has enabled the utilization of the comparative genomics approach in PRR identification and the study of evolution, structural features, and functions in many animal species including avian. In the present review, we focused on PRR sensing and signaling functions in the avian species, domestic chicken, mallard, and domestic goose. In addition to summarizing recent advances in the understanding of avian PRR functions, the present review utilized a comparative biology approach to identify additional PRRs, whose functions have been well studied in mammalians but await functional characterization in avian.


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