The purpose of the paper is to study the effect of temperature change on the theory of inner product vector (IPV). The IPV method can be used to detect structural damage. This study evaluates the IPV ...method ability to detect damage of an Airbus A320 slat-track, which is in the form of a longitudinal crack. The results show that the IPV method is able to detect defects in the structure as well as its location, with close approximation. Then, the Airbus A320 slat-track was investigated for the effect of changes in temperature on the IPV method, evaluated over a temperature between –73 and 260 °C. The effect of temperature on the performance of IPV damage detection method has not been investigated so far. The results of the IPV method show a spurious defect in the structure as the temperature changes; therefore, the IPV method is temperature-sensitive. Also, this study highlighted the importance of applying simulation methods to develop vibration-based damage detection (VBDD) techniques, especially for evaluating the effect of changes in environmental temperature when the structure is complex.
A comprehensive investigation of evolvability and design reuse in new and historical civil jet transport aircraft was undertaken. The main purpose was to characterise the techniques and strategies ...used by aircraft manufacturers to evolve their designs. Such knowledge is essential to devise improved design methods for promoting the evolvability of new aircraft. To perform the study, jet aircraft from three large western manufacturers (Boeing, Airbus, and McDonnell Douglas) were investigated in depth. The academic and industrial literature was combed to find descriptions of design reuse and change across each major model of all three manufacturers. The causes and effects of the changes are explored, and the amenability of the different airframes to change are discussed. The evolution of the payload and range capabilities of the different aircraft was also investigated. From these studies, it was found that the initial approach to derivative designs appears somewhat ad hoc and that substantial modifications were devised in quick succession to increase both range and capacity. From the 1970s, two distinguishable patterns started to appear – a ‘leap and branch’ and a ‘Z’ pattern. The leaps correspond to major changes in both propulsion and airframe, whereas the branches are simple ‘stretches’ or ‘shrinks’. The Z pattern, also documented by other authors, is a progressive increase in range, followed by a simple stretch, and then another increase in range. Design changes were investigated further by grouping them according to the assumed payload-range objectives set for the derivatives. Finally, the maximum changes found for salient geometrical design parameters amongst all the aircraft surveyed were documented. Developing methods to support the creation of leaps (especially across configurations) appears to be one of the most promising avenues for future research.
Studying civil aircraft emergency evacuation process by using computer model is an effective way. In this study, the evacuation of Airbus A380 is simulated using a Finer-Grid Civil Aircraft ...Evacuation (FGCAE) model. In this model, the effect of seat area and others on escape process and pedestrian’s “hesitation” before leaving exits are considered, and an optimized rule of exit choice is defined. Simulations reproduce typical characteristics of aircraft evacuation, such as the movement synchronization between adjacent pedestrians, route choice and so on, and indicate that evacuation efficiency will be determined by pedestrian‘s “preference” and “hesitation”. Based on the model, an assessment procedure of aircraft evacuation safety is presented. The assessment and comparison with the actual evacuation test demonstrate that the available exit setting of “one exit from each exit pair” used by practical demonstration test is not the worst scenario. The half exits of one end of the cabin are all unavailable is the worst one, that should be paid more attention to, and even be adopted in the certification test. The model and method presented in this study could be useful for assessing, validating and improving the evacuation performance of aircraft.
•The internal structure of aircraft can be well reproduced for the finer-grid.•The effect of seat area and others on escape process is considered.•The model takes into account pedestrian’s hesitation before leaving exits.•An optimized rule of exit choice is defined.•An assessment procedure of aircraft evacuation safety is presented.
Airliner accidents are often accompanied by incidental aircraft fires, causing huge casualties and incalculable economic losses. The research on airliner fire and its emergency evacuation is the ...focus and difficulty of aviation safety research, but it is difficult to carry out the research through experiments, and the use of computer simulation is an effective method. This paper comprehensively studies the dynamic development of the cabin fire and the corresponding cabin evacuation when the wide-body airliner Airbus A350-900 is forced to land in two states: horizontal and forward. The spatial distribution of the remaining evacuation time at each seat is used to analyze and judge the safety evacuation risk of the airliner cabin. Finally, two evacuation optimization design ideas based on partition guidance and seat layout are proposed to improve the spatial distribution of the overall evacuation risk of passengers in the cabin and provide some reference suggestions for strengthening fire prevention in the design, manufacture, and use of airliner. Some targeted countermeasures are put forward for the emergency evacuation of passengers in the cabin in a fire situation.
This article analyzes the influence and foreseeable evolution of three main leadership styles in sustainable development for social reconstruction in two leading companies, the European Airbus and ...the Indian Tata Advanced Systems Ltd. (TASL) (Hyderabad, India). Inductive research was employed, using two cross-national case studies and a comparative analysis applying statistical testing. Data were collected through interviews and a survey among principal company leaders with several functions. The study focused on three styles: transactional, transformational, and servant leadership. The strength of this paper is that it sheds light on an understudied industry by providing findings on both the present (as-is) state and the advisable reorientation (i.e., future state suggested by respondents). This could contribute to filling the current gap in understanding the influence of leadership styles on the aerospace and defense industries’ economic, social, and environmental outcomes. By analyzing the results obtained in both companies, we concluded that even though all three styles are present in both companies, servant and transformational leadership provide better results for sustainable development for social reconstruction. Regarding the advisable reorientation, according to the respondent’s suggestions, the style best suited to influence sustainable development for social reconstruction in the long term in both companies is the servant style. As for the transitional phase, respondents suggest a hybrid leadership model, encompassing features of both the transformational and the servant styles.
This article undertakes a comparative analysis of the corporate social responsibility (CSR) drivers and barriers in the European multinational Airbus and the Indian Tata Advanced Systems Ltd. (TASL), ...both in their current, as-is state, and in the desirable future, should-be state. These in-depth case studies are based on structured interviews, complemented with a survey. The research findings provide qualified, bounded support to the currently preponderant view among CSR scholars, regarding both the preeminent role of the internal (vs. external) drivers and the key importance of moral-driven (vs. profit-driven) drivers such as the values of the top management. The caveat here reflects that, contingent on cultural issues, individual companies might not have reached this state yet. Furthermore, these findings suggest that the current CSR situation could be characterized as contingent, transitional and convergent; the practical implications for the various CSR stakeholders of this characterization are discussed. The most salient trait, convergence, suggests the existence of a certain commonality in CSR’s foreseeable evolutionary path, even among disparate companies, converging on such aspects as the ever-increasing role of the value system and of the shared, internalized company culture, and the shift of CSR’s role from obligation to potential source of competitive advantage.
In the present study, a hybrid deep learning reduced-order model (ROM) is applied for the prediction of wing buffet pressure distributions on a civil aircraft configuration. The hybrid model is ...compound of a convolutional variational neural network autoencoder (CNN-VAR-AE) and a long short-term memory (LSTM) neural network. The CNN-VAR-AE is used for the reduction of the high-dimensional flow field data, whereas the LSTM is applied to predict the temporal evolution of the pressure distributions. For training the neural network, experimental buffet data obtained by unsteady pressure sensitive paint measurement (iPSP), is applied. As a test case, the Airbus XRF-1 configuration is selected, considering two different experimental setups. The first setup is defined by a wind tunnel model with a clean wing, whereas the second setup includes an ultra high bypass ratio engine nacelle on each wing. Both configurations have been tested in the European Transonic Windtunnel, considering several transonic buffet conditions. Finalizing the training of the hybrid neural networks, the trained models are applied for the prediction of buffet flow conditions which are not included in the training data set. A comparison of the experimental results and the pressure distributions predicted by the hybrid ROMs indicate a precise prediction performance. Considering both aircraft configurations, the main buffet flow features are captured by the hybrid ROMs.
Due to the increasing ship trafficking, illegal fishing, cargo crimes, drug crimes, identifying people in the sea, shipwrecked etc., it is essential to detect ships to monitor and control maritime ...crime. Researchers have been working constantly and facing challenges to automatically detect ships, mainly in remote sensing, which has shown a great impact in providing safety, detecting illegal trade, pollution, and oil slick monitoring. In this paper, 192,555 satellite images of ships have been used to train the deep learning models such as customized CNN, ResNet152V2, InceptionResNetV2, MobileNetV2, NasNetLarge, DenseNet201, and EfficientNetB7. The dataset has been first pre-processed to remove any noisy signals before being graphically represented using exploratory data analysis to study the pixel intensities of data. Later, feature extraction techniques such as image masking, image augmentation, and contour features are applied to create bounding boxes corresponding to the detected ship’s localizing coordinates. The models are further evaluated using the ship detected and ship not detected classes. It has been discovered that customized CNN achieved the highest precision by 96.16 as well as 95.64 and F1 score value by 99.89 and 95.99 in terms of both the classes, respectively. In contrast, DenseNet201 had the highest recall 95.46, and 93.45, for the ship, detected and not detected classes, respectively).
Texts written in Simplified Technical English present semantic and syntactic restrictions with respect to standard English that should be considered in the implementation of natural language ...processing systems dealing with controlled natural languages. This paper explores the syntax and semantics of adjuncts in a controlled natural language, namely, the Simplified Technical English (ASD-STE100) used in the Airbus corpus with a view to observing how the peculiarities identified in the behaviour of Airbus adverbials should be reflected in the computational treatment of these constituents. Thus, our main aim is to contribute to the computational implementation of the prototype ARTEMIS by designing the parsing rules and the catalogue of feature-bearing matrixes that encode the grammatical constraints of Airbus adjuncts. The parsing rules reflect the positional preferences of the various peripheral types and capture the semantic variability of adjuncts in the corpus. In addition, they provide a weight factor that predicts the scale of markedness of these constituents with respect to the different positions that they occupy in the clause. On the whole, these properties offer a precise description of the syntactic features of adverbials that will facilitate their automatic processing.
One of the major subsystems of each airplane is the landing gear system which must be capable of tolerating extreme forces applied to structure during ground maneuver to improve vibration absorbing ...performance. The traditional landing gear system performs this function well under normal condition, whereas with varying condition of landing and situation of the runway for the airplane, performance of this system decreases noticeably. In this research, for overcoming this problem, the coefficients of controller, the parameters of hydraulic nonlinear actuator added to the traditional shock absorber system, and the vibration absorber are optimized simultaneously by the bee intelligent multi-objective algorithm. As well as, for proving adaptability of this algorithm, this paper presents the sensitivity analysis of three point landing due to the additional payload and the touchdown speed and the robustness analysis of one and two point landings due to the wind conditions as emergency situation on the runway as an innovated work. In order to evaluate the effectiveness and the efficiency of proposed method, the flight dynamic differential equations of an Airbus 320–200 vibrational model during the landing phase are derived and through the numeric technique are solved. The results of numerical analysis for this large-scale airplane model with six degrees of freedom demonstrate that the active shock absorber system in accordance with two types of the bee multi-objective algorithm has good performance in comparison with the passive approach to minimize the bounce displacement and momentum, the pitch displacement and momentum, the suspension travel and impact force in time-domain and frequency-domain by using signal processing, that results in improvement of passenger ride comfort importantly. As well as, enhancement of structure’s fatigue life is a likely case as a consequence of study applicable to the industry.
PDF
