Добірка наукової літератури з теми "Aeronautical complex structures"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Aeronautical complex structures".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Aeronautical complex structures"
1
Rodríguez, Rosamaria, A. Yarza, J. López-Díez, C. Cuerno-Rejado, and A. Güemes. "Damage Detection on Typical Aeronautical Structures." Key Engineering Materials 293-294 (September 2005): 677–84. http://dx.doi.org/10.4028/www.scientific.net/kem.293-294.677.
Повний текст джерелаАнотація:
The paper pursues the exploration of the feasibility and reliability of current damage detection technologies, evaluating their detection capabilities, environmental factors effects, false alarms rate, adaptability to complex geometries, etc. The method to be used is based on finite element modal updating. Three aspects, as outlined below, are covered: testing samples will be aluminium sheets (0.6m x 0.4m x 1.6mm) strengthened with riveted L-shaped stiffeners. Data will be presented from the undamaged specimens. Secondly, the testing of the samples with damage simulated at different places by temporary removal of specific rivets, thus affecting the overall structural characteristics of the structure. The models used for damage identification methods will be fine tuned to properly detect the simulated damages. Finally, using this information, the paper resumes the capabilities of the method to detect and locate the simulated damage.
2
Proietti, Alice, Nicola Gallo, Denise Bellisario, Fabrizio Quadrini, and Loredana Santo. "Damping Behavior of Hybrid Composite Structures by Aeronautical Technologies." Applied Sciences 12, no. 15 (August 8, 2022): 7932. http://dx.doi.org/10.3390/app12157932.
Повний текст джерелаАнотація:
Hybrid composite laminates are manufactured by using technologies and raw materials of the aeronautic sector with the aim to improve the damping behavior of composite structures. Matrix hybridization was achieved by laminating carbon fiber reinforced (CFR) plies with elastomer interlayers. Up to 10 different composite sandwich architectures were investigated by changing the stacking sequence, the thickness of the elastomer layers, and the elastomer typology, whereas the total number of the CFR plies was fixed to six for all the hybrid composites. Square panels with the size of 300 × 300 mm2 were autoclave molded with vacuum bagging, and rectangular samples were extracted for static and dynamic tests. Dynamic mechanical analyses were performed to measure the storage modulus and loss factor of hybrid materials, which were compared with static and dynamic performances of the composite structures under bending. Repeated loading–unloading cycles and free oscillation tests allowed us to the energy loss per unit of volume, and the acceleration damping, respectively. Results show that softest elastomer interlayers lead to big loss of stiffness without any positive effect in the damping behavior, which worsens as well. By using soft elastomers, complex architectures do not provide any additional benefit in comparison with the traditional sandwich structure with soft core and hard skins.
3
Oboe, Daniele, Luca Colombo, Claudio Sbarufatti, and Marco Giglio. "Shape Sensing of a Complex Aeronautical Structure with Inverse Finite Element Method." Sensors 21, no. 4 (February 17, 2021): 1388. http://dx.doi.org/10.3390/s21041388.
Повний текст джерелаАнотація:
The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.
4
Efimov, V. V. "On the matter of the terminology of aeronautical structures survivability." Dependability 19, no. 2 (June 16, 2019): 42–47. http://dx.doi.org/10.21683/1729-2646-2019-19-2-42-47.
Повний текст джерелаАнотація:
Aim. The paper examines the existing definitions of survivability and damage tolerance (operational survivability) of aeronautical structures. An attempt is made to unambiguously define the survivability of aeronautical structures that can subsequently be extended to an aircraft as a whole and other complex technical items. The primary goal of this paper is to clearly distinguish between dependability and survivability. In order to ensure efficient operation and flight safety, an aircraft must possess airworthiness, a comprehensive characteristic of an aircraft that is defined by the implemented design principles and solutions and that allows performing safe flights under expected conditions and under the established methods of operation. The expected operating conditions are described in the Aviation Regulations – Airworthiness Requirements. Despite the fact that compliance with the Airworthiness Requirements ensures a sufficiently high level of flight safety, the most vital structural components are designed in such a way as to remain operable even under extreme conditions beyond the expected operating conditions. But dependability cannot be responsible for operability outside the expected operating conditions. Conclusion suggests itself that under extreme conditions beyond the expected operating conditions operability is to be ensured by another property, i.e. survivability. Methods. This research was conducted using the logical and probabilistic approaches. The author examined literary sources primarily dedicated to the matters of dependability and survivability of aeronautical structures, as well as other complex technical items. In order to ensure an optimal understanding of the differences and correlation between the concepts of dependability and survivability, the probabilistic approach was used. Results. Upon the analysis of literary sources, survivability was defined as the property of an item to retain in time the capability to perform the required functions under extreme conditions beyond the expected operating conditions under the specified methods of maintenance, storage and transportation. Additionally, the paper proposes the definition of damage tolerance (operational survivability) as the property of an item to retain in time the capability to perform the required functions under extreme conditions beyond the expected operating conditions depending on the methods of maintenance, storage and transportation. The probabilistic approach to the delimitation of the concepts of dependability and survivability of aeronautical structures was examined using the known indicator of operating efficiency of a transport aircraft that is represented as the mathematical expectation of the efficiency indicator. An aircraft may be either in the expected operating conditions or in extreme conditions beyond the expected operating conditions. No third option exists. Then, the sum of the probabilities of an aircraft encountering such conditions must be equal to one. The probability of no-failure can be calculated by means of the probability of the contrary event, i.e. the probability of failure that can be represented as the product of the probability of an aircraft encountering certain operating conditions and the probability of failure in such conditions. For the case of extreme conditions beyond the expected conditions the well-known concepts of perishability and vulnerability with the author’s improvements can be used. Conclusions. A definition of survivability was obtained that is clearly different from the concepts of dependability and fail-safety. Additionally, the concept of damage tolerance (operational survivability) was proposed that was introduced similarly to the previously introduced concept of operational dependability.
5
Efimov, V. V. "On the matter of the terminology of aeronautical structures survivability." Dependability 19, no. 2 (June 16, 2019): 43–48. http://dx.doi.org/10.21683/1729-2646-2019-19-2-43-48.
Повний текст джерелаАнотація:
Aim. The paper examines the existing definitions of survivability and damage tolerance (operational survivability) of aeronautical structures. An attempt is made to unambiguously define the survivability of aeronautical structures that can subsequently be extended to an aircraft as a whole and other complex technical items. The primary goal of this paper is to clearly distinguish between dependability and survivability. In order to ensure efficient operation and flight safety, an aircraft must possess airworthiness, a comprehensive characteristic of an aircraft that is defined by the implemented design principles and solutions and that allows performing safe flights under expected conditions and under the established methods of operation. The expected operating conditions are described in the Aviation Regulations – Airworthiness Requirements. Despite the fact that compliance with the Airworthiness Requirements ensures a sufficiently high level of flight safety, the most vital structural components are designed in such a way as to remain operable even under extreme conditions beyond the expected operating conditions. But dependability cannot be responsible for operability outside the expected operating conditions. Conclusion suggests itself that under extreme conditions beyond the expected operating conditions operability is to be ensured by another property, i.e. survivability. Methods. This research was conducted using the logical and probabilistic approaches. The author examined literary sources primarily dedicated to the matters of dependability and survivability of aeronautical structures, as well as other complex technical items. In order to ensure an optimal understanding of the differences and correlation between the concepts of dependability and survivability, the probabilistic approach was used. Results. Upon the analysis of literary sources, survivability was defined as the property of an item to retain in time the capability to perform the required functions under extreme conditions beyond the expected operating conditions under the specified methods of maintenance, storage and transportation. Additionally, the paper proposes the definition of damage tolerance (operational survivability) as the property of an item to retain in time the capability to perform the required functions under extreme conditions beyond the expected operating conditions depending on the methods of maintenance, storage and transportation. The probabilistic approach to the delimitation of the concepts of dependability and survivability of aeronautical structures was examined using the known indicator of operating efficiency of a transport aircraft that is represented as the mathematical expectation of the efficiency indicator. An aircraft may be either in the expected operating conditions or in extreme conditions beyond the expected operating conditions. No third option exists. Then, the sum of the probabilities of an aircraft encountering such conditions must be equal to one. The probability of no-failure can be calculated by means of the probability of the contrary event, i.e. the probability of failure that can be represented as the product of the probability of an aircraft encountering certain operating conditions and the probability of failure in such conditions. For the case of extreme conditions beyond the expected conditions the well-known concepts of perishability and vulnerability with the author’s improvements can be used. Conclusions. A definition of survivability was obtained that is clearly different from the concepts of dependability and fail-safety. Additionally, the concept of damage tolerance (operational survivability) was proposed that was introduced similarly to the previously introduced concept of operational dependability.
6
Rahbari, Amirhossein, Marc Rébillat, Nazih Mechbal, and Stephane Canu. "Unsupervised damage clustering in complex aeronautical composite structures monitored by Lamb waves: An inductive approach." Engineering Applications of Artificial Intelligence 97 (January 2021): 104099. http://dx.doi.org/10.1016/j.engappai.2020.104099.
Повний текст джерела
7
Leski, Andrzej, Wojciech Wronicz, Piotr Kowalczyk, Michał Szmidt, Robert Klewicki, Karol Włodarczyk, and Grzegorz Uliński. "Modular Test Stand for Fatigue Testing of Aeronautical Structures – Verification of Assumptions." Fatigue of Aircraft Structures 2020, no. 12 (December 1, 2020): 78–91. http://dx.doi.org/10.2478/fas-2020-0008.
Повний текст джерелаАнотація:
Abstract The Modular Test Stand was developed and manufactured to decrease the cost of fatigue testing and reduce the time of its completion as well as to enable testing specimens under more complex load conditions. The stand consists of three connected sections, similar to a wing box, all being loaded in the same way. Thanks to that, several specimens can be tested simultaneously. This configuration requires that stress and strain distribution should be reasonably uniform, as assumed in the design stage. The structure can be loaded with bending or torsion. A whole section, selected structural node or a specimen mounted in the structure as well as a repair or a sensor can be a test object. Two stands, one for bending and one for torsion were prepared. This paper presents the verification of the assumed strain and stress distributions on the skin panels. The measurements were performed with the use of Digital Image Correlation (DIC) as well as strain gauges. DIC measurements were performed on one skin panel of the central section. Five strain gauge rosettes were installed on both panels of the one section. In addition, one rosette was applied to one skin panel in each of two other sections. Measurements were performed on the stand for torsion as well as on the stand for bending. The results of DIC analysis and strain gauge measurement during torsion show uniform shearing strain distributions on the panels. During bending, on the tensioned side, the strains obtained indicate quite uniform strain distributions. On the compressed side, local buckling of the skin panels results in high strain gradients. Strain levels obtained with the use of a DIC analysis and strain gauge measurements were similar. Moreover, horizontal displacements of markers in the spar axis during bending was determined based on a series of photographic. The deflection line obtained in this way has a shape similar to arc, which is characteristic of the constant bending moment. The stand was tested with torsional and bending loads in order to verify the design assumptions. The results of strain distributions on the skin panels with the use of DIC and strain gauges as well as the deflection line of the spar axis indicate that the Modular Test Stand performs as assumed and can be used for tests.
8
Wichniarz, Marzena. "Certification of Testing Laboratories – The Basis of Reliability Among Research Vendors in Aviation." Fatigue of Aircraft Structures 2021, no. 13 (December 1, 2021): 99–105. http://dx.doi.org/10.2478/fas-2021-0009.
Повний текст джерелаАнотація:
Abstract Material characterization and assessment is a crucial stage in most of aviation and aeronautical research and a basis for further design and testing of more complex aircraft elements and structures. Material test’s reliability can only be guaranteed by conducting them at independent and reliable laboratories, operating based on a management system assessed by a third-party such as the accreditation according to the ISO / IEC 17025 or NADCAP or having the qualification of the second-party based on specific customer requirements. This paper introduces basic requirements for material testing laboratories according to accreditation systems and describes its responsibilities as qualified and reliable testing suppliers.
9
Su, Yong Zhen, Xin Wen Liu, Da Yu Li, Xin Bing Wang, and Yu Heng Zhang. "Research on Impact Localization in Composite Materials Using Array Signal Processing and Lamb Wave." Advanced Materials Research 304 (July 2011): 65–72. http://dx.doi.org/10.4028/www.scientific.net/amr.304.65.
Повний текст джерелаАнотація:
Impact localization is one of the major concerns in maintenance of aircraft structures built from composites. A lot of different techniques like acoustic emission, optimization technique based on system are nowadays investigated to identify impact location. But the method to identify impact position in complex composite structure with high accuracy in real time has not been completely established. In the present work, a new efficient method is proposed for identifying impact location in real and complex composite structure based on array signal processing and Lamb waves. There are two steps in the proposed method. The first step is to estimate the direction- of-arrival (DOA) of impact source using continuous wavelet transform (CWT) and array signal processing; the second step is to estimate the distance between impact source and the coordinate origin based on propagation characteristic of Lamb wave and CWT. The composite panel with stepped thickness of a real and complex aeronautical tank is used to verify the present methodology. The result shows that the present method may identify impact location fast and accurately.
10
IORDACHE, Valentin-Marian, and Casandra Venera PIETREANU. "Considerations on control processes in aeronautical organizations in the context of improving safety and efficiency." INCAS BULLETIN 11, no. 1 (March 5, 2019): 207–15. http://dx.doi.org/10.13111/2066-8201.2019.11.1.16.
Повний текст джерелаАнотація:
In modern aeronautical systems, one of the biggest challenges for the management structures is to maintain the control at all levels. Operational safety and efficiency impose the need to control all the associated risks and hazards; thus, in order to achieve organizational performance, a very important aspect is to establish and develop a strong organization with respect to operations and objectives. Nevertheless, performance cannot be achieved without control; the continuous technological development and the environmental variabilities have a great impact on the organizational management processes. Organizations are very complex and they will continue to expand due to the increasing demands of flight operations. The capacity to adapt, considering the permanent transformations in the society, represents a continuous process that needs to be carefully carried in order to diminish or eliminate the errors that may occur due to organizational factors. Controlling each operational step from the beginning represents the premises for obtaining stability and performance.
Дисертації з теми "Aeronautical complex structures"
1
VIGLIETTI, ANDREA. "Low Fidelity and High Fidelity Structural Models for Hybrid Composite Aircraft Structures." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2710182.
Повний текст джерелаАнотація:
This thesis extends advanced one-dimensional models derived from the use of the Carrera Unified Formulation (CUF) to a High-Fidelity modeling approach, which has been used to perform analyses of multi-component aeronautical structures guaranteeing a proper description of each component regarding geometry and material.
Static analyses and free vibration analyses have been performed to validate the current CUF model for the studies of structures, which present multi-component nature, sweep angle and non-prismatic shape; subsequently, its capabilities have been exploited to investigate different aeronautical topics.
At first, the model has been used for the free vibration analysis of damaged structures and the possible use of the behavior alterations for the damage detection. Thanks to the capability of the model to control the stiffness arbitrarily, several scenarios have been analyzed where the damage has been introduced, for example, in the whole component or at the local level. The layer-wise capability of the model has allowed a wide tailoring analysis of thin-walled boxes to be performed. It has been used to evaluate the free-vibration behaviors according to the lamination used in the structure. Moreover, these analyses have been used to explore the possible influences on the geometrical coupling effects due to sweep angle or tapered shapes, in order to mitigate or emphasize them. The model has also been extended to the study of Variable Angle Tow (VAT) composites characterized by curvilinear fibers. After the validation with results from the open literature, the possible advantages in the aeronautic field of this technology have been explored through vibrational analyses of prismatic thin-walled boxes.
The results confirm the capabilities of the current model to deal with very complex aeronautical structures providing accurate results with a sensible reduction of the computational cost compared to the classical used FEM models. Its performances are also tested with a displacement analyses in the second part of this thesis, which presents the work done during the apprenticeship related to the research project TIVANO with the company Leonardo Finmeccanica – Aircraft division.
2
Fripp, Michael 1970. "Weighted arrays for modal isolation and active control of complex structures." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9175.
Повний текст джерелаАнотація:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.Includes bibliographical references (p. [161]-172).
Arrays of sensors and actuators are designed to provide modal isolation and robust broadband feedback control on complex structures with high performance and limited modeling. The weighted array technique proposed here enables the design of reduced-order controllers for complex structures and offers the potential to improve closed-loop robustness and to broaden the region of good performance even as the plant changes. The weighted summation of the transducer signals senses the modes that are relevant to performance while rejecting the remaining modes; therefore reducing the required complexity of the controller. These weights are obtained from the minimization of a cost function and, under certain assumptions, it can be shown that a single optimum solution exists. The use of weighted arrays is motivated by the need to control the vibration response of aircraft. A representative fuselage test-bed was designed to retain the essential structural-acoustic dynamics of aircraft on a reduced size structure. Sensing and actuation plies of piezoelectric transducers were bonded to the fuselage test-bed and to other representative cylinder sections. Array weights were computed and successfully applied to isolate the targeted modes. The modal isolation allowed the implementation of simple control algorithms on the complex structures. Different methods of computing the weights are implemented and compared. The deleterious effects of spatial aliasing, the performance as a function of the array size, the sensitivity to random perturbations, and the effects of transducer failure are explored.
by Michael L. Fripp.
Ph.D.
Книги з теми "Aeronautical complex structures"
1
G, Barton Noel, and Periaux Jacques, eds. Coupling of fluids, structures, and waves in aeronautics: Proceedings of a French-Australian workshop in Melbourne, Australia, 3-6 December 2001. Berlin: Springer, 2003.
Знайти повний текст джерела
2
United States. Congress. House. Committee on Science. Subcommittee on Space and Aeronautics. Range modernization.: Joint hearings before the Subcommittee on Space and Aeronautics of the Committee on Science and the Subcommittee on Military Research and Development and Subcommittee on Military Procurement of the Committee on Armed Services, House of Representatives, One Hundred Sixth Congress, first session, March 24 and June 29, 1999. Washington: U.S. G.P.O., 2000.
Знайти повний текст джерела
3
US GOVERNMENT. Range modernization: Joint hearings before the Subcommittee on Space and Aeronautics of the Committee on Science and the Subcommittee on Military Research ... first session, March 24 and June 29, 1999. For sale by the U.S. G.P.O., Supt. of Docs., Congressional Sales Office, 2000.
Знайти повний текст джерела
4
Coupling of Fluids, Structures and Waves in Aeronautics: Proceedings of a French-Australian Workshop in Melbourne, Australia 3-6 December 2001 (Notes on ... and Multidisciplinary Design (NNFM)). Springer, 2003.
Знайти повний текст джерелаЧастини книг з теми "Aeronautical complex structures"
1
Schlag, Mareike, Kai Brune, Hauke Brüning, Michael Noeske, Célian Cherrier, Tobias Hanning, Julius Drosten, et al. "Extended Non-destructive Testing for Surface Quality Assessment." In Adhesive Bonding of Aircraft Composite Structures, 119–222. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-319-92810-4_3.
Повний текст джерелаАнотація:
AbstractThis chapter introduces various extended non-destructive testing (ENDT) techniques for surface quality assessment, which are first characterized, then enhanced, and finally applied to assess the level of pre-bond contaminations intentionally applied to carbon fiber reinforced plastic (CFRP) adherends following the procedures described in the previous chapter. Based on two user cases comprising different scenarios that are characteristic of either aeronautical production or repair, the detailed tests conducted on two types of sample geometry, namely flat coupons and scarfed pilot samples with a more complex shape, form the basis for applying the advanced ENDT procedures for the monitoring of realistic and real aircraft parts, as will be described in Chap. 10.1007/978-3-319-92810-4_5. Specifically, the reported investigations were performed to assess the surface quality of first ground and then intentionally contaminated CFRP surfaces using the following ENDT tools: the aerosol wetting test (AWT), optically stimulated electron emission (OSEE), two differently implemented approaches based on electronic noses, laser-induced breakdown spectroscopy (LIBS), Fourier-transform infrared (FTIR) spectroscopy, laser-induced fluorescence (LIF), and laser vibrometry.
2
Prado, Malila, and Adriana Mendes Porcellato. "“When I land - if I ever land”: exploring if-clauses in Aeronautical English." In Aviation English - A global perspective: analysis, teaching, assessment, 71–86. Bookerfield Editora, 2022. http://dx.doi.org/10.53268/bkf22080504.
Повний текст джерелаАнотація:
Conditional sentences are listed in the complex structure glossary of Doc 9835 (ICAO, 2010). Recent research has found that expressions with if are relevant in the plain aviation English used in R/T communications (PRADO, 2019) but has not examined these fully. Following Prado (2019, 2021a), the present study investigates if-clauses in a corpus of radio communications in abnormal situations (PRADO; TOSQUI-LUCKS, 2019), with a view to identifying the functions they perform in plain aviation English (BIESWANGER, 2016) and how they can inform aviation English teaching and assessment. A corpusbased analysis revealed that of the 310 occurrences of if in the corpus, 60% were employed in requests and orders, 22% in indirect questions, and only 18% expressed conditionality such as “When I touch down / if I ever touch down / do I just kill the throttle or what?” Then, for each of the three functions, we examined the structures in which the conjunction if was used and compared them with traditionally taught conditional structures so as to inform aviation English pedagogical materials and resources from a pragmatic perspective and in the light of real language use (ISHIHARA, 2022).
3
Pacheco, Aline. "Reported speech in Aviation English: an analysis through two specific corpora." In Aviation English - A global perspective: analysis, teaching, assessment, 55–70. Bookerfield Editora, 2022. http://dx.doi.org/10.53268/bkf22080503.
Повний текст джерелаАнотація:
Aviation English is a specialized language and, as such, features some specific structures that should be carefully analyzed to be dealt with appropriately. Reported Speech (RS) constitutes an essential communicative function for pilots and controllers because they must often relay information to different parties in complex communication scenarios. Regarding the teaching and learning of RS, the most traditional orientation is that it should observe tense backshifting - the possibilities of not shifting back the tense seem to be treated as exceptions, even in specialized coursebooks. This study discusses the use of RS in aeronautical communications by analyzing the occurrences of this structure in two specialized corpora – CORPAC, the Corpus of Pilot and ATC Communications and RTPEC, the Radiotelephony and Plain English Corpus, examining reporting verbs used in actual conversation samples and strictures after the verbs ‘said’ and ‘told’. The main findings show the most used reporting verbs and suggest that around 50% of the indirect reported clauses in aviation maintain the original tense, which seems to be evidence that pilots and ATCs choose to report no changes in the scenario when relaying information in a similar proportion to choosing to backshift. Accordingly, teaching and learning resources like specialized coursebooks or tailordesigned materials should factor the real communication features in their activities.
4
Yuki, Kazuhisa. "Visualization of Complex Flow Structures by Matched Refractive-Index PIV Method." In Aeronautics and Astronautics. InTech, 2011. http://dx.doi.org/10.5772/17786.
Повний текст джерела
5
Tosqui-Lucks, Patrícia, Juliana de Castro Santana, and Patrícia Palhares Tupinambá de Sá. "Games, corpus and medals – challenging and innovating experiences in Aeronautical English hybrid learning." In Aviation English - A global perspective: analysis, teaching, assessment, 137–50. Bookerfield Editora, 2022. http://dx.doi.org/10.53268/bkf22080507.
Повний текст джерелаАнотація:
This chapter presents an innovative training program conceived in the hybrid mode (synchronous virtual interactions and asynchronous e-learning) - for the Aeronautical English Learning. We discuss the conception, elaboration and implementation processes of trainings designed for Brazilian air traffic controllers, based on the linguistic categories of the ICAO rating scale (Pronunciation, Structure, Vocabulary, Comprehension, Fluency and Interaction). The faceto-face or synchronous virtual part of the training was developed to offer a better understanding of the rating scale descriptors by clarifying the differences between operational and nonoperational proficiency levels. The elaboration of the game-like activities for the second part of the training was data-driven. The data were composed of frequent mistakes compiled in a corpus with oral productions of students who have attended other courses; as well as difficulties presented by candidates who have obtained proficiency levels 2 or 3 in the Aeronautical English Proficiency Exam (EPLIS); and linguistic problems collected by experienced teachers. The combined work of English Language Experts (ELE) along with Aeronautical Subject Matter Experts (SME) has played an important role in the development of both parts of this hybrid learning tool. The gamification of Aeronautical English for Specific Purposes (ESP) has shown to be an engaging and more appealing environment for proficiency level elevation.
6
Kashyap, Ramgopal. "Decision Support Systems in Aeronautics and Aerospace Industries." In Automated Systems in the Aviation and Aerospace Industries, 138–65. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7709-6.ch005.
Повний текст джерелаАнотація:
The aim of this chapter is to utilize the upkeep hypothesis of on-condition, condition checking. It proposes support ideas: for example, advanced upkeep, proactive upkeep which is bolstered by solid checking and finding strategies to enhance the effectiveness of upkeep extraordinarily; so there must be decision support system framework to develop a present-day flying upkeep framework. Maintenance DSS can give powerful choice help to aeronautics support. It additionally makes strides in upkeep effectiveness and controls support costs. The flying MDSS still needs further research on the accompanying subjects. Since current airplanes have numerous frameworks and complex structures, numerous flight parameters need to be screened. Step-by-step instructions to assemble an effective database and research criteria for judging the adequacy of ongoing information should direct further research. Since continuous flight status information has cost issues, how to set up the data download criteria should direct further research.
7
Kashyap, Ramgopal. "Decision Support Systems in Aeronautics and Aerospace Industries." In Research Anthology on Decision Support Systems and Decision Management in Healthcare, Business, and Engineering, 1196–223. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-9023-2.ch057.
Повний текст джерелаАнотація:
The aim of this chapter is to utilize the upkeep hypothesis of on-condition, condition checking. It proposes support ideas: for example, advanced upkeep, proactive upkeep which is bolstered by solid checking and finding strategies to enhance the effectiveness of upkeep extraordinarily; so there must be decision support system framework to develop a present-day flying upkeep framework. Maintenance DSS can give powerful choice help to aeronautics support. It additionally makes strides in upkeep effectiveness and controls support costs. The flying MDSS still needs further research on the accompanying subjects. Since current airplanes have numerous frameworks and complex structures, numerous flight parameters need to be screened. Step-by-step instructions to assemble an effective database and research criteria for judging the adequacy of ongoing information should direct further research. Since continuous flight status information has cost issues, how to set up the data download criteria should direct further research.
8
Paul, Saptarshi. "Understanding Aviation English: Challenges and Opportunities in NLP Applications for Indian Languages." In Air Traffic Management and Control [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99612.
Повний текст джерелаАнотація:
English is a language that is understood, spoken and used by citizens of a diverse array of countries. The speakers include both native and non-native speakers of English. NLP or Natural Language Processing on the other hand is a branch of computer science that deals with one of the most challenging aspect that a machine can process: dealing with Natural Languages. Natural languages which have evolved over centuries are complete, diverse and highly complex and thus are challenging for a computer system to understand and process. MT or Machine Translation is a more specific part of NLP that translates one natural language to another (English being one of the major researched and sought after languages among them). Though research in the field of NLP and MT has come a long way and many efficient translators are available, still Translation and other NLP applications in specialized domains such as aeronautics are still today a challenge for NLP researchers and developers to achieve. NLP applications are often used in education of English Language, and are therefore a continuous process for Non-Native speakers of English. Non-native English speakers take help of various NLP tools such as E-Dictionary, MT applications and others to better understand the English language and thus learn it better and faster. Aviation English poses a challenge to MT systems and understanding it as a whole requires specialized handling as it has own phonetic pronunciations and terminologies and constituent Out-Of-Vocabulary words. Dealing with Aviation English calls for teaming up of experts from Applied Linguistics, NLP and AI. As a result it becomes a cross-research discipline that covers situations that demand real time use of proper language, e.g. ATC communications. This Paper aims to discuss most recent research methodologies that deals with the Aviation English and reviews the problems posed by it. Being a specialized and structured form of English, the problems are faced by both native and non-native speakers of English Language. Discussion is carried out in the relevant and recent advances of methods in dealing with aviation English language challenges from both, the Human (ICAO/DGCA/AAI) as well as NLP angle. Lastly we have a look at how these challenges are linked to scope for development of applied technologies. Research in experiential Aviation English situations deals with both English for Specific Purposes - ESP (Aeronautics in our case) as well as situations in English as a Foreign Language i.e. EFL (English-Indian language pair).
9
Mespoulet, Jérôme, and Pierre Louis Hereil. "An Overview of Theoretical and Experimental Techniques for Material Behavior Characterization in Shock Physics." In Critical Energy Infrastructure Protection. IOS Press, 2022. http://dx.doi.org/10.3233/nicsp220005.
Повний текст джерелаАнотація:
Shock Physics that deals with material behavior at a very high strain rate (in the order of material propagation speed) reveals more and more its importance in engineering applications (automotive, defense, aeronautic, space, energy, etc.), geophysics (earth’s behavior, asteroid impacts) or astrophysics (planets and stars behavior). Nowadays, this term is used more often when classical high-speed dynamics reach their physical limits. After a short introduction to shock physics, an application to lightweight armor is used to illustrate the importance of coupling tuned experiments with simulations for dynamic material studies: In fact, lightweight armors of soldiers are in constant evolution to optimize protection efficiency. In this area, more and more complex simulations are investigated with compound structures including polymeric foam, composite, metal, and ceramic. Even if numerical capabilities are in perpetual evolution, there is a constant need of improving the knowledge of individual material response in the strain, strain rate regime closed to the threat. Collecting parameters for Equation Of State (EOS), strength and/or rupture models to fit material models is thus mandatory to ensure reliable numerical investigations. Since 2015, THIOT INGENIERIE Shock Physics Laboratory has been selected by the French Ministry Of Defense (MOD) Land Systems to perform materials characterization in three main families of ballistic materials. Parallel to those tasks, in-house simulations done by the dynamic material department have shown a very good agreement with validation tests based on the dynamic material characterizations. A coupled approach between laboratory experiments and numerical simulations has shown its relevance with ceramic, [1], an Ultra High Molecular Weight Polyethylene composite (UHMWPE) [2] and a polymeric foam [3]. For all those materials, the BBA methodology has been used to calibrate EOS, strength, and damage models by conducting a step-by-step procedure with a dual approach, mixing together experimental tests and numerical works simultaneously.
Тези доповідей конференцій з теми "Aeronautical complex structures"
1
Viglietti, Andrea, Enrico Zappino, and Erasmo Carrera. "A Component-Wise Approach for the Failure of Complex Aeronautical Structures." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71249.
Повний текст джерелаАнотація:
Using advanced beam models based on the Carrera Unified Formulation, this paper presents an analysis of a damaged tapered aircraft structure. Results obtained from static and free vibration analyses are presented to evaluate the evolution of the stress and the modal behaviour in a multi-component damaged structure. This 1-D model is able to modify the material proprieties, then the stiffness, at the local level. In this way, many types of local and global damage can be introduced into the structure. The results show the capability of the present model to obtain with a low computational cost, displacements, stresses and vibration characteristics of damaged structures making him a good candidate for design and maintenance tools.
2
Carreres, M., L. M. García-Cuevas, J. García-Tíscar, and M. Belmar-Gil. "Spectral Analysis of an Aeronautical Lean Direct Injection Burner Through Large Eddy Simulation." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14998.
Повний текст джерелаАнотація:
Abstract During the last decades, many efforts have been invested by the scientific community in minimising exhaust emissions from aeronautical gas turbine engines. In this context, many advanced ultra-low NOx combustion concepts, such as the Lean Direct Injection treated in the present study, are being developed to abide by future regulations. Numerical simulations of these devices are usually computationally expensive since they imply a multi-scale problem. In this work, a non-reactive Large Eddy Simulation of a gaseous-fuelled, radial-swirled Lean-Direct Injection (LDI) combustor has been carried out through the OpenFOAM Computational Fluid Dynamics (CFD) code by solving the complete inlet flow path through the swirl vanes and the combustor. The geometry considered is the gaseous configuration of the CORIA LDI combustor, for which detailed measurements are available. Macroscopical analysis of the main turbulent features related to the swirling flow and the generated Central Recirculation Zone (CRZ) are well established in the literature. Nevertheless, a more in-depth characterization is still required in this area of active research since theory and experimental data are not yet able to predict which unstable mode dominates the flow. This work aims at using Large Eddy Simulation for a complete characterisation of the unsteady flow structures generated within the combustion chamber of a gaseous methane injection immersed in a strong non-reactive swirling flow field. To do so, a spectral analysis of the flow field is performed to identify the frequency, intensity and instabilities associated to the phenomena occurring at the swirler outlet region. A coherent structure known as Precessing Vortex Core (PVC) is identified both at the inner and the outer shear layers, resulting in a periodic disturbance of the pressure and velocity fields. The pressure and velocity fluctuations predicted by the CFD code are used to compute the spectral signatures through the Sound Pressure Level (SPL) amplitude at multiple locations. This allows investigating both the complex behaviour of the PVC and its associated acoustic phenomena. The acoustic characteristics computed by the numerical model are first validated qualitatively by comparing the spectrum with available experimental data. In this way, the use of dimensionless numbers to characterise the most energetic structures is coherent with the experimental observations and the characteristics of the PVC. Then, the numerical identification of the main acoustic modes in the chamber through Dynamic Mode Decomposition (DMD) allows overcoming the Fast Fourier Transform (FFT) shortcomings and better understanding the propagation of the hydrodynamic instability perturbations. This investigation on the main non-reacting swirling flow structures inside the combustor provides a suitable background for further studies on combustion instability mechanisms.
3
Chung, Daniel, and Kihong Ku. "Digitally-driven Fabrication of Fiber-reinforced Composite Panels for Complex Shaped Envelopes." In AIA/ACSA Intersections Conference. ACSA Press, 2016. http://dx.doi.org/10.35483/acsa.aia.inter.16.2.
Повний текст джерелаАнотація:
Composite materials have been explored in architecture for their high performance characteristics that allow customization of functional properties of lightness, strength, stiffness and fracture toughness. Particularly, engineering advancements and better understanding of fiber composites have resulted in growing applications for architectural structures and envelopes. As most new developments in material fabrication start outside the realm of architecture such as in automobile and aeronautical industries, there is need to advance knowledge in architectural design to take advantage of new fabrication technologies. The authors introduce results of new digitally driven fabrication methods for fiber-reinforced composite sandwich panels for complex shaped buildings. This presentation discussed the material properties, manufacturing methods and fabrication techniques needed to develop a proof of concept system using off-the-shelf production technology that ultimately can be packaged into a mobile containerized facility for on-site panel production. The researchers conducted experiments focusing on developing a digitally controlled deformable mold to create composite relief structures for highly customized geometrical façade components. Research findings of production materials, fabrication methods and assembly techniques, are discussed to offer insights into novel opportunities for architectural composite panel fabrication and commercialization.
4
Carrera, E., A. Pagani, and M. Petrolo. "Static and Dynamic Analysis of Aircraft Structures by Component-Wise Approach." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63600.
Повний текст джерелаАнотація:
This paper proposes an advanced approach to the analysis of reinforced-shell aircraft structures. This approach, denoted as Component-Wise (CW), is developed by using the Carrera Unified Formulation (CUF). CUF is a hierarchical formulation allowing for the straightforward implementation of any-order one-dimensional (1D) beam theories. Lagrange-like polynomials are used to discretize the displacement field on the cross-section of each component of the structure. Depending on the geometrical and material characteristics of the component, the capabilities of the model can be enhanced and the computational costs can be kept low through smart discretization strategies. The global mathematical model of complex structures (e.g. wings or fuselages) is obtained by assembling each component model at the cross-section level. Next, a classical 1D finite element (FE) formulation is used to develop numerical applications. It is shown that MSC/PATRAN can be used as pre- and post-processor for the CW models, whereas MSC/NASTRAN DMAP alters can be used to solve both static and dynamic problems. A number of typical aeronautical structures are analyzed and CW results are compared to classical beam theories (Euler-Bernoulli and Timoshenko), refined models and classical solid/shell FE solutions from the commercial code MSC/NASTRAN. The results highlight the enhanced capabilities of the proposed formulation. In fact, the CW approach is clearly the natural tool to analyze wing structures, since it leads to results that can be only obtained through three-dimensional elasticity (solid) elements whose computational costs are at least one-order of magnitude higher than CW models.
5
Georgiou, Ioannis T., and Nikolaos Kintzios. "Discovering Irregular Diagnostic Proper Orthogonal Decomposition Signatures in Healthy Marine Ball Bearings." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89173.
Повний текст джерелаАнотація:
Presented is a structural health condition diagnosis based on optimal space-time decompositions of ensembles of acceleration signals developed in the complex physical domain of marine ball bearings when interrogated by a set of diagnostic impulsive forces. Ensembles of diagnostic forces and ensembles of collocated responses acceleration signals are decomposed into proper orthogonal modes. Typical inner and ensembles of nondestructive impact diagnostic forces covering three times the inner and outer races are strongly dominated by a single POD mode with uniform spatial distribution and a sharp pulse time modulation. There exist high order modes with very small amount of energy. This indicates that the impact response of the suspended ball bearing depends slightly on the impact location. Diametrically opposite, the typical ensemble of radial acceleration signals collected at a point on the outer race has a very broad POD energy spectrum. All POD modes have energy fractions of the same order and irregular (no periodic) space modulations. Despite this spatial irregularity, all POD spatial modulations have astonishingly common statistical properties: nearly zero mean values, and nearly identical standard deviations at the value level of the uniform spatial distribution of the dominant POD mode of the ensembles of diagnostic forces. The result is that the healthy ball bearing spreads nearly evenly the energy of collocated acceleration signals to a large number of POD modes. The analysis aims at gaining a basic understanding of the behavior of collocated acceleration signals developed in the complex domains of multi-body flexible structures with applications in structural health monitoring of marine-aeronautical machinery critical elements such as propellers, bearings, brakes, clutches and gearboxes.
6
Malik, Afzaal M., Ejaz M. Qureshi, Naeem Ullah Dar, and Iqbal Khan. "Residual Stress Fields Under Different Clamping Conditions in Circumferentially Welded Thin-Walled Cylinders." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48422.
Повний текст джерелаАнотація:
Arc welding is a reliable joining method widely utilized in nuclear, pressure vessels, aerospace and aeronautical structures to ensure the intended in service behaviour during the thermal and/or pressure loadings. Weld induced deformations and high residual stresses often occur during the course of welding. These cause significant threats for the structural integrity of the nuclear power plant components, particularly in stress corrosion inhibited environments owing to the risk of stress corrosion cracking (SCC). In this research, the consequences of five different structural boundary conditions on the evolution of residual stress fields after the welding are investigated. Both experimental and numerical simulations based on finite element modeling are employed during the course of investigation. Full three-dimensional FE models for the circumferentially, arc welded thin-walled cylinders are developed in ANSYS®. The complex coupled, thermo-mechanical phenomenon during the welding is simulated by sequentially coupled approach enhanced by user written APDL subroutines. The role of welding restraints in minimizing / optimizing the residual stresses is presented and discussed in detail. The result reveals that residual stresses show weak dependence on the degree of the restraints. Although the stress levels slightly varies in magnitude, but similar trend is observed for all the structural clamping conditions under study. Simulation results validated through full-scale experiments with high-tech reliably instrumented welding and measuring equipments shows promising features of the developed modelling and simulation strategy for use in shop floor applications.
7
Santos, Hugo. "Equilibrium-Based Finite Element Formulation for Timoshenko Curved Tapered Beams." In VI ECCOMAS Young Investigators Conference. València: Editorial Universitat Politècnica de València, 2021. http://dx.doi.org/10.4995/yic2021.2021.12567.
Повний текст джерелаАнотація:
Due to their excellent mechanical performance and structural efficiency, curved tapered beams have been widely used in many engineering applications, such as, bridge structures, piping systems, biomedical devices, aerospace and aeronautical structures, etc. Their complex geometries pose challenges to the development of robust approaches for the modelling of their mechanical behaviour. Among the various approaches available in the literature for their analysis, those that are based on the finite element method have been the most successful, particularly due to their versatility. Nonetheless, when applied to Timoshenko based structural models, some of these finite element approaches are prone to shear locking when the beam elements become slender and to membrane locking when the curvature of the beam centroid curves increases [1]. The aim of the present contribution is to introduce a novel, simple and effective, finite element formulation for the analysis of two-dimensional Timoshenko curved tapered beams. This formulation relies on a complementary variational approach based on a set of approximations that satisfy in strong form all equilibrium conditions of the boundary-value problem [2], resulting thus in a formulation that is free from both shear and membrane locking phenomena. The effectiveness of the formulation is numerically demonstrated through its application to a circular clamped-clamped beam subjected to a mid-span concentrated load, and the obtained results are analysed and discussed. REFERENCES [1] H. Stolarski and T. Belytschko, “Shear and membrane locking in curved C0 elements”, Comput. Meth. Appl. Mech. Eng., Vol. 41, pp. 279–296, (1983). [2] H.A.F.A. Santos, “Complementary-energy methods for geometrically non-linear structural models: an overview and recent developments in the analysis of frames”, Archives of Computational Methods in Engineering, Vol. 18, (2011): 405.
8
Eymann, S., U. Reinmo¨ller, R. Niehuis, W. Fo¨rster, M. Beversdorff, and J. Gier. "Improving 3D Flow Characteristics in a Multistage LP Turbine by Means of Endwall Contouring and Airfoil Design Modification: Part 1 — Design and Experimental Investigation." In ASME Turbo Expo 2002: Power for Land, Sea, and Air. ASMEDC, 2002. http://dx.doi.org/10.1115/gt2002-30352.
Повний текст джерелаАнотація:
Endwall losses contribute significantly to the overall losses in modern turbomachinery, especially when aerodynamic airfoil load and pressure ratios are increased. Hence, reducing the extent and intensity of the secondary flow structures helps to enhance overall efficiency. This work focusses on secondary flow reduction in typical aero engine low pressure turbines. From the large range of viable approaches, a promising combination of axis symmetric endwall contouring and 3D airfoil thickening was chosen. Aerodynamic design, experimental verification and further analysis based on numerical simulation are described in a two part paper. In the first part, the aerodynamic design intent and the experimental setup embedded in the closed circuit test facility of the Institute of Aeronautical Propulsion at Stuttgart University are presented. For this work, a three stage turbine of realistic aero engine size was investigated with a conventional and a modified first stage. In order to gain detailed information about the complex flow different advanced measurement techniques were employed. In addition to multiple surface pressure tappings, extensive traverses were taken in several measurement planes with pneumatic probes, 3-component hot-wire probes and non-intrusive laser transit velocimetry. Time-averaged results of these measurements are reported for two different points of operation. By comparing the two configurations of the first stage the influencing of the secondary flow structure is made apparent through a variation in the radial extent and intensity of the endwall secondary flow motion.
9
FENZA, ANGELO DE, ASSUNTA SORRENTINO, DONATO PERFETTO, ALESSANDRO DE LUCA, GIUSEPPE PETRONE, and FRANCESCO CAPUTO. "Elliptical Triangulation Method for Damage Identification on a Complex Aeronautical Structure." In Structural Health Monitoring 2019. Lancaster, PA: DEStech Publications, Inc., 2019. http://dx.doi.org/10.12783/shm2019/32106.
Повний текст джерела
10
Bridel-Bertomeu, Thibault, Laurent Y. Gicquel, and Gabriel Staffelbach. "Wall Modeled LES and its Impact on Rotor/Stator Cavity Unsteady Features." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57244.
Повний текст джерелаАнотація:
Cavity flows are essential components of many aeronautical and spatial engines. For example, in gas turbines a network of cavities is calibrated and managed to divert part of the main cold stream which is then re-injected in the hot regions of the engine to shield walls from the hot combustion products. For pumps, cavities are naturally present at the junction of fixed and rotating parts. In both contexts, mastering the flow stability in rotor/stator cavities is essential to avoid imposing too large flow variations which could lead to miss-tuned operating conditions in the engine and a drastic loss of performance or life-span. Although stability of these flows has been widely studied in the literature, a lack of clear understanding of the triggering mechanisms from stable to unstable flow solutions remains, especially in the context of industrial applications where Reynolds numbers are very high and difficult to handle. To cope with such complex geometry, fully unsteady flows, the so-called Large Eddy Simulation (LES) approach appears as a very promising method. However and for such high Reynolds number industrial applications, wall modeling still remains a necessity to alleviate the computational cost of LES. Understanding the impact of such a strong modeling hypothesis on the mean flow features and unsteady energetic content is hence mandatory and the objective of the present discussion. To do so, the present paper studies LES flow solutions in an enclosed rotor-stator configuration with a stationary shroud. These simulations are performed using a two-steps Taylor-Galerkin finite-element scheme coupled to a WALE subgrid scale model giving a better prediction of the eddy viscosity in zones of strong shear. This allows capturing the unsteady structures known to be present in the boundary layers. Two sets of statoric boundary conditions are investigated: the dynamics of the boundary layer is either resolved using a fine mesh grid or modeled using a classic boundary layer law of the wall. It is shown that the modeling of the stationary disc layer induces an underestimation of the flow velocity at low radii and loss of accuracy in the radial description of the boundary layer structures. Despite these differences, the most energetic structures are found to have the same azimuthal organization as in the wall resolved configuration as well as the same pulsation, which in turn produces a boundary layer with the same spectral content as in the wall resolved test case.