Artykuły w czasopismach: „Manoeuvre loads”

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Dekker, S., G. Wurzel i R. Alderliesten. "Reliability modelling for rotorcraft component fatigue life prediction with assumed usage". Aeronautical Journal 120, nr 1232 (8.07.2016): 1658–92. http://dx.doi.org/10.1017/aer.2016.79.

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ABSTRACTFatigue life is a random variable. Thus, the reliability of a conservative fatigue life prediction for a component in the helicopter dynamic system needs to be substantiated. A standard analytical substantiation method uses averaged manoeuvre loads instead of seeing manoeuvre loads as a random variable whose distribution is estimated with limited precision. This simplification may lead to inaccuracies. A new simulation-based method is developed to conservatively predict fatigue life, while also accounting for the full random distribution and uncertainty of manoeuvre loads. Both methods fully account for uncertain fatigue strength but assume that the mission profile is known or can at least be conservatively estimated. Simulations under synthetic but realistic engineering conditions demonstrate that both methods may be used for accurate substantiation of conservative fatigue life predictions. The simulations also demonstrate that, under the tested conditions, uncertainties from manoeuvre loads may be neglected in fatigue life substantiations as the resulting error is not significant with respect to uncertainties in component fatigue strength.

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Kowaleczko, Grzegorz, i Andrzej Leśniczak. "Modelling of Helicopter Main Rotor Aerodynamic Loads in Manoeuvres". Journal of KONES 26, nr 4 (1.12.2019): 273–84. http://dx.doi.org/10.2478/kones-2019-0118.

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AbstractThe article discusses the method of modelling of the helicopter main rotor aerodynamic loads during steady state flight and manoeuvres. The ability to determine these loads was created by taking into account the motion of each blade relative to the hinges and was a result of the applied method of aerodynamic loads calculating. The first part of the work discusses the basic relationships that were used to build the mathematical model of helicopter flight. The focus was also on the method of calculating of the aerodynamic forces generated by the rotor blades. The results of simulations dedicated to the “jump to hover” manoeuvre were discussed, showing the possibilities of analysing aerodynamic loads occurring in unsteady flights. The main rotor is considered separately in an “autonomous” way and treated as a source of averaged forces and moments transferred to the hub. The motion of individual blades is neglected, and their aerodynamic characteristics are radically simplified. The motion of individual blades is neglected, and their aerodynamic characteristics are radically simplified. This can lead to significant errors when attempting to model dynamic helicopter manoeuvres. The more complex model of helicopter dynamics is discussed.

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Irving, P. E., J. E. Strutt, R. A. Hudson, K. Allsop i M. Strathern. "The contribution of fatigue usage monitoring systems to life extension in safe life and damage tolerant designs". Aeronautical Journal 103, nr 1030 (grudzień 1999): 589–95. http://dx.doi.org/10.1017/s0001924000064228.

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Abstract Fatigue usage monitoring systems (Fums) offer considerable potential for life extension of aircraft parts. In this work the life extension benefits of Fums is assessed by adopting a probabilistic approach. The roles of damage law type and of service usage variability is explored. It is shown by analysis that in the absence of cycle to cycle load interaction effects, load sequence has no effect on eventual life in either linear or non linear damage laws, provided that the function describing the rate of damage growth has separable variables of stress and damage. This condition includes fracture mechanics crack growth laws. Monte Carlo simulations have been conducted of fatigue life distributions in helicopter rotor components. Variability in manoeuvre damage, when summed over a large number of manoeuvres, has little effect on scatter in overall lives. A fixed manoeuvre usage spectrum will result in very small scatter in lives, whereas keeping the usage constant for each helicopter and allowing it to vary between helicopters, produces a significantly increased variability. The influence of load factors on life is also assessed. The extent of possible maintenance credits is discussed together with the use of Bayesian updating to make optimum use of both prior design data and current loads or damage information provided by Fums.

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Bordogna, Marco Tito, Paul Lancelot, Dimitri Bettebghor i Roeland De Breuker. "Static and dynamic aeroelastic tailoring with composite blending and manoeuvre load alleviation". Structural and Multidisciplinary Optimization 61, nr 5 (9.01.2020): 2193–216. http://dx.doi.org/10.1007/s00158-019-02446-w.

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AbstractIn aircraft design, proper tailoring of composite anisotropic characteristics allows to achieve weight saving while maintaining good aeroelastic performance. To further improve the design, dynamic loads and manufacturing constraints should be integrated in the design process. The objective of this paper is to evaluate how the introduction of continuous blending constraints affects the optimum design and the retrieval of the final stacking sequence for a regional aircraft wing. The effect of the blending constraints on the optimum design (1) focuses on static and dynamic loading conditions and identifies the ones driving the optimization and (2) explores the potential weight saving due to the implementation of a manoeuvre load alleviation (MLA) strategy. Results show that while dynamic gust loads can be critical for wing design, in the case of a regional aircraft, their influence is minimal. Nevertheless, MLA strategies can reduce the impact of static loads on the final design in favour of gust loads, underlining the importance of considering such load-cases in the optimisation. In both cases, blending does not strongly affect the load criticality and retrieve a slightly heavier design. Finally, blending constraints confirmed their significant influence on the final discrete design and their capability to produce more manufacturable structures.

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Barbieri, Nilson, Rubem Penteado de Melo, Key Fonseca de Lima i Gabriel de Sant’Anna Vitor Barbieri. "Dynamical analysis of B-train vehicle combination with liquid cargo". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, nr 14 (21.03.2019): 3871–81. http://dx.doi.org/10.1177/0954407019838127.

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In this work, a combination of B-train type vehicle is dynamically analysed through lateral movement at low speed manoeuvre known as Lane Change Manoeuvre. The analyses were conducted for a vehicle with liquid loads of 100%, 80%, 60% and 40% capacity. The analyses involve adjusting the steer angle through an objective function taking into account the numerical and experimental lateral acceleration of the tractor vehicle. The movement of the liquid (slosh) during the manoeuvres are approximated using the software Pasimodo and trammel pendulum. Considering the upper surface of the liquid inside the tank as a straight line, it is possible to obtain the centre of gravity variation and the moment of inertia through polynomial adjustments. In this way, it is possible to analyse numerically the behaviour of the vehicle with liquid load in a curved trajectory. To obtain modal parameters, the operational modal analysis technique is used. With the applied methodology, it was possible to find good agreement between the numerical and experimental values of the acceleration signals in four different positions in the vehicle combination. Through the analyses of the vehicle with fluid in movement, it was possible to verify a great variation of load in the wheels due to transfer of load of the vehicle travelling by curved trajectories or due to evasive manoeuvres. This is a critical condition that can lead the vehicle to rollover condition. The experimental data were obtained for the vehicle at constant speed (between 30 and 40 km/h) and under these conditions, the vehicle is considered stable by analysing the eigenvalues.

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Kowaleczko, Grzegorz, Tomasz Kwaśniak, Mirosław Nowakowski i Mirosław Michalczewski. "Analysis of aerodynamics and main rotor loads under stalled conditions of helicopter’s main rotor during the pull-up manoeuvre". Journal of KONBiN 48, nr 1 (1.12.2018): 7–29. http://dx.doi.org/10.2478/jok-2018-0045.

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Abstract The article discusses the main features of the applied simulation model of helicopter flight indicating references, where it was elaborated in detail. It focuses on presenting the simulation results of pull-up manoeuvre during which the helicopter does not respond correctly. The reasons for the behaviour as mentioned above were explained based on the results of calculations. The capabilities of the simulation model were used to determine the current loads of particular blades of the helicopter’s main rotor. The results were illustrated by maps of the angles of attack and aerodynamic lift on the surface of the main rotor and the distributions of these parameters along blades on characteristic azimuth for individual manoeuvre phases.

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Popov, G., S. Sankar, T. S. Sankar i G. H. Vatistas. "Dynamics of Liquid Sloshing in Horizontal Cylindrical Road Containers". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 207, nr 6 (listopad 1993): 399–406. http://dx.doi.org/10.1243/pime_proc_1993_207_147_02.

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A study of the liquid behaviour in horizontal cylindrical road containers undergoing a steady turning manoeuvre is presented and discussed. The steady state solutions are derived analytically from the hydrostatic equations. The transient solutions are obtained by numerical integration of the Navier-Stokes, continuity and free-surface equations. The non-dimensional governing equations are solved in primitive variables by using a modified marker-and-cell technique which involves the interpolation-reflection type boundary conditions developed for this investigation. The mathematical model of the liquid motion includes all essential non-linear effects and allows the damped natural frequencies of liquid vibrations to be obtained as well as the magnitudes of the liquid slosh loads. This study also enables the coupled directional dynamics of the ‘vehicle-liquid tank’ system undergoing different road manoeuvres to be investigated by integrating the non-linear fluid slosh model and an appropriate vehicle model simultaneously.

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Sinha, Kautuk, Thomas Klimmek, Matthias Schulze i Vega Handojo. "Loads analysis and structural optimization of a high aspect ratio, composite wing aircraft". CEAS Aeronautical Journal 12, nr 2 (7.02.2021): 233–43. http://dx.doi.org/10.1007/s13272-021-00494-x.

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AbstractComposite structures have shown a prominent impact in the aircraft structural design. With an increasing shift towards incorporating more composite materials in the primary aircraft structure it is imperative to have corresponding design tools to simplify the design process. In the present work, a simplified implementation for composite optimization has been developed within the DLR-AE (German Aerospace Centre, Institute of Aeroelasticity) automated aeroelastic structural design framework cpacs-MONA. This paper presents the results of structural optimization of a high aspect ratio composite wing aircraft model developed in the DLR project ATLAs. The generation of almost all involved simulation models for this study is done using the in-house DLR tool ModGen. An aeroelastic trim analysis is conducted for various manoeuvre and gust conditions. A load selection process is used to determine the most relevant sizing load cases. A comparison is made between the optimization results of a composite wing and an aluminium wing to demonstrate the more favourable strength to weight ratio of the composite wing. A manoeuvre load alleviation procedure has been introduced in the load calculation process. The results show further weight savings in the design process when load alleviation is utilized due to reduction in the span wise bending moment.

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Leonelli, Luca, Stefano Cattabriga i Silvio Sorrentino. "Driveline instability of racing motorcycles in straight braking manoeuvre". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, nr 17 (28.09.2017): 3045–61. http://dx.doi.org/10.1177/0954406217730093.

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Experimental evidence shows that a self-excited vibration may appear during braking manoeuvres performed by road-racing motorcycles. It involves vertical oscillation of front and rear wheel axles as well as angular oscillation of the driveline in a frequency range between 17 and 22 Hz. As a consequence, severe oscillations of the tyre-ground vertical loads can be observed, leading to a loss of grip and ultimately weakening the vehicle overall performance. Several contributions on this topic can be accounted for in the literature; however, a comprehensive description of the phenomenon has not been given yet. The present work is aimed at simulating the above vibration with a planar multibody motorcycle model, and then at analyzing its driving mechanism. Stability maps are drawn for time-invariant braking manoeuvres, and validated with respect to time domain simulations.

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Stanisławski, Jarosław. "Simulation of Boundary States of Helicopter Flight". Journal of KONES 26, nr 2 (1.06.2019): 137–44. http://dx.doi.org/10.2478/kones-2019-0042.

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Abstract Results of simulation of main rotor blade loads and deformations, which can be generated during boundary states of helicopter flight, are presented. Concerned cases of flight envelope include hover at maximum height, level flight at high velocity, pull-up manoeuvres applying cyclic pitch and mixed collective and cyclic control. The simulation calculations were executed for data of light helicopter with three-bladed articulated rotor. For analysis, the real blades are treated as elastic axes with distributed masses of blade segments. The model of deformable blade allows for out-of-plane bending, in plane bending, and torsion. For assumed flight state of helicopter, the equations of rotor blades motion are solved applying Runge-Kutta method. According to Galerkin method, for each concerned azimuthal position of blade the parameters of its motions are assumed as a combination of considered bending and torsion eigen modes of the blade. The loads of rotor blades generated during flight depend due to velocity of flight, helicopter mass, position of rotor axis in air and deflections of swashplate that correspond to collective and cyclic pitch angle applied to rotor blades. The results of simulations presenting rotor loads and blade deformations are shown in form of time-runs and as plots of rotor-disk distributions. The simulations of helicopter flight states may be useful for prediction the conditions of flight-tests without exceeding safety boundaries or may help to define limitations for manoeuvre and control of helicopter.

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Lim, J. W. "Consideration of structural constraints in passive rotor blade design for improved performance". Aeronautical Journal 120, nr 1232 (4.07.2016): 1604–31. http://dx.doi.org/10.1017/aer.2016.77.

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ABSTRACTThis design study applied parameterisation to rotor blade for improved performance. In the design, parametric equations were used to represent blade planform changes over the existing rotor blade model. Design variables included blade twist, sweep, dihedral and the radial control point. Updates to the blade structural properties with changes in the design variables allowed accurate evaluation of performance objectives and realistic structural constraints – blade stability, steady moments (flap bending, chord bending and torsion) and the high-g manoeuvre pitch link loads. Performance improvement was demonstrated with multiple parametric designs. Using a parametric design with advanced aerofoils, the predicted power reduction was 1.0% in hover, 10.0% at μ = 0.30 and 17.0% at μ = 0.40, relative to the baseline UH-60A rotor, but these were obtained with a 35% increase in the steady chord bending moment at μ = 0.30 and a 20% increase in the half peak-to-peak pitch link load during the UH-60A UTTAS manoeuvre. Low vibration was maintained for this design. More rigorous design efforts, such as chord tapering and/or structural redesign of the blade cross section, would enlarge the feasible design space and likely provide significant performance improvement.

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Bocheński, Damian. "Investigations of operational driving loads of bucket chains and manoeuvre hoisting winches on multi-bucket dredgers". Polish Maritime Research 15, nr 3 (1.10.2008): 42–48. http://dx.doi.org/10.2478/v10012-007-0082-1.

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Investigations of operational driving loads of bucket chains and manoeuvre hoisting winches on multi-bucket dredgers The paper concerns problems of preliminary designing of bucket dredgers' power plants. This paper presents results of investigations of six bucket dredgers in service. The operational investigations consisted in measuring the parameters which characterize working conditions of two main receivers of mechanical energy: bucket chains and swing winches. In the paper characteristics of disposition of loading of bucket chains and swing winches are presented. They covered average value, standard deviation and coefficient of variance of loading disposition mutability. Examples of load distributions of chains' and group of swing winches on chosen dredgers during some period of time were given. Conclusions in view to average values of main receivers of mechanical energy and coefficients of variance of loadings spred were formulated. Results of investigations of dependence of average loadings of main receivers on their nominal power were presented. The results of work will be used in creation of random models describing real conditions of operation of power plant elements of dredgers.

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Grm, Aleksander. "Ships Added Mass Effect on a Flexible Mooring Dolphin in Berthing Manoeuvre". Journal of Marine Science and Engineering 9, nr 2 (21.01.2021): 108. http://dx.doi.org/10.3390/jmse9020108.

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This paper deals with the hydrodynamic effect of the ship on a flexible dolphin during a mooring manoeuvre. The hydrodynamic effect refers to the change in momentum of the surrounding fluid, which is defined by the concept of added mass. The main reason for the present study is to answer the question, “What is the effect of the added mass compared to the mass of the ship during the mooring procedure for a particular type of ship?” Measured angular frequencies of dolphin oscillations showed that the mathematical model can be approximated by the zero frequency limit. This simplifies the problem to some extent. The mooring is a pure rocking motion, and the 3D study is approximated by the strip theory approach. Moreover, the calculations were performed with conformal mapping using conformal Lewis mapping for the hull geometry. The fluid flow is assumed to be non-viscous, non-rotating and incompressible. The results showed that the additional mass effect must be taken into account when calculating the flexible dolphin loads.

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Wojtas, Małgorzata, i Agnieszka Sobieszek. "Gyroplane Rotor Hubs Strength Tests". Journal of KONES 26, nr 3 (1.09.2019): 265–70. http://dx.doi.org/10.2478/kones-2019-0082.

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Abstract In this article a review of rotor, hub constructions were presented. Discussed rotor’s hub is made of composite or aluminum alloys materials. Two types of rotor hub were presented (four-blades and two-blades teetering rotor hub), each of them are dedicated to gyroplanes. Typical gyroplane main rotors are characterized by simple design, especially in case of rotors for light gyroplanes. In the following part of the article the type of strength tests required by certification process were shown. The test programs based on legal aspects of admission to the flight tests taking into account legislation such as CS 27 (Subpart C – Strength Requirements), CAP 643 British Civil Airworthiness requirements Section T Light gyroplanes, ASTM F2972. Furthermore, this article discusses strength tests of gyroplane rotor hub such as measured parameters, methodology of measurement, types of sensors, course of test, test stands, and limit loads. The loads during “pull-up from level flight” manoeuvre are limit loads during tests. Required additional processes, like a verification the same parameters by two types of method were shown i.e. deformation of structure were tested by strain gauges and reverse engineering. Strength tests had to be made before flight test, based on results of them aircrafts are flight authorized. In conclusion, the results of tests were presented and fulfilment of legal assumptions and requirements were shown.

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Lim, J. W. "Consideration of structural constraints in passive rotor blade design for improved performance". Aeronautical Journal 119, nr 1222 (grudzień 2015): 1513–39. http://dx.doi.org/10.1017/s0001924000011386.

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AbstractThis design study applied parameterisation to rotor blade for improved performance. In the design, parametric equations were used to represent blade planform changes over the existing rotor blade model. Design variables included blade twist, sweep, dihedral, and radial control point. Updates to the blade structural properties with changes in the design variables allowed accurate evaluation of performance objectives and realistic structural constraints – blade stability, steady moments (flap bending, chord bending, and torsion), and the high g manoeuvring pitch link loads. Performance improvement was demonstrated with multiple parametric designs. Using a parametric design with advanced aerofoils, the predicted power reduction was 1·0% in hover, 10·0% at μ = 0·30, and 17·0% at μ = 0·40 relative to the baseline UH-60A rotor, but these were obtained with a 35% increase in the steady chord bending moment at μ = 0·30 and a 20% increase in the half peak-to-peak pitch link load during the UH-60A UTTAS manoeuvre Low vibration was maintained for this design. More rigorous design efforts, such as chord tapering and/or structural redesign of the blade cross section, would enlarge the feasible design space and likely provide significant performance improvement.

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Colley, B. A., R. G. Curtis i C. T. Stockel. "Towards Intelligent Ships in Marine Training Simulators". Journal of Navigation 39, nr 1 (styczeń 1986): 75–81. http://dx.doi.org/10.1017/s0373463300014247.

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An application of the model to manoeuvre ships based on the range to domain over range rate (RDRR) concept is described. A simulation of a training simulator has been set up on which the target ships manoeuvre by the RDRR model in response to mariner controlled ships. Results of experiments show that the RDRR model manoeuvres targets realistically. The applications are reduced instructor work load and increased simulator reality. The method has the potential for development to manoeuvre ships at sea.B. A. Colley is now with Plessey Marine, R. G. Curtis is with the Department of Trade and Industry and C. T. Stockel is at Plymouth Polytechnic.

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Fry, A., R. Cook i N. Revill. "CVF ski-jump ramp profile optimisation for F-35B". Aeronautical Journal 113, nr 1140 (luty 2009): 79–85. http://dx.doi.org/10.1017/s0001924000002803.

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Abstract This paper presents a summary of the principles and processes used to design a ski-jump ramp profile for the UK’s Future Aircraft Carrier (CVF) optimised for the Joint Strike Fighter (JSF). The paper includes an overview of the CVF and JSF programs, a history and summary of the ski-jump ramp and the principles of its use in the shipborne Short Take-Off (STO) manoeuvre. The paper discusses the importance of defining optimisation boundaries including specified objectives, aircraft configurations and environmental conditions. It then demonstrates the process of balancing the design drivers of air vehicle performance and landing gear loads to achieve an optimum profile. Comparisons are made between the proposed candidate CVF ramp profile and the current in service ski-jump design as designed for the Harrier family of aircraft. The paper briefly covers some of the important issues and factors that have been experienced when a theoretical profile is translated into a physical ramp fitted to a ship, principally the effects on aircraft operations due to build and in-service variation from the nominal profile.

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Sbarufatti, Claudio, Andrea Manes i Marco Giglio. "On the Integration of Real-Time Diagnosis and Prognosis for Scheduled Maintenance Optimization". Key Engineering Materials 569-570 (lipiec 2013): 1044–51. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.1044.

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Helicopters are very critical aircrafts from the point of view of fatigue loads. A structural damage could grow fast to critical size because of the wide range of manoeuvre loads. As a consequence, scheduled maintenance is a major cost during the operative life of the aircraft. The most advanced methodologies for Structural Health Monitoring and Prognostic Health Management available today are aimed to provide a real-time structural diagnosis, thus maximizing the availability of the helicopter and reducing the maintenance costs. However, on-board diagnostic systems might be gradually introduced in the current maintenance procedures, trying to minimize the risk associated to these newly developed technologies. The work presented inside this paper is about the simulation of the integration of real-time diagnosis and prognosis into a typical scheduled maintenance procedure. A diagnostic unit is capable for anomaly detection and damage quantification (in terms of crack length). It is trained with Finite Element simulated damages and tested with real experimental data. The diagnostic output is then processed in a particle filter algorithm, based on sequential importance sampling technique, aimed at refining the estimation of the structural condition as well as to update the inference on the residual useful life distribution. The coupling of real-time diagnosis with off-line measures (taken during scheduled maintenance stops) is analyzed and applied to a damage tolerant structure, trying to outline the advantages and drawbacks of the proposed approach.

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Krake, Luther. "Helicopter Airframe Fatigue Spectra Generation". Advanced Materials Research 891-892 (marzec 2014): 720–25. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.720.

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Helicopter airframe fatigue cracking is a cause of significant and growing cost of ownership and operational readiness concerns for the operators of (primarily) metallic airframe helicopters. Airframe fatigue has often had relatively low priority for helicopters, with research and design concentrated on the fatigue of flight critical rotating structural components such as rotor blades and pitch links. The Australian Defence Science and Technology Organisation (DSTO) and the US Naval Air Systems Command are collaborating to develop improved methods and technologies that can be used to assess the fatigue damage endured by ageing helicopter airframes. The flight load sequencesor fatigue spectraexperienced by a helicopter airframe in its lifetime contain many billions of load cycles due to rotor revolutions. Fatigue spectra developed for helicopter airframe certification tests are heavily simplified for reasons such as computational efficiency, test practicality and cost. Real airframe fatigue spectra are likely to be influenced by the modes of vibration that might be present on the airframe, the attenuation of the vibratory loading that is introduced at the main and tail rotors and the relative magnitudes and influences of both quasi-static (manoeuvre induced) and vibratory loading. To better capture such complexity, more realistic, higher fidelity fatigue spectra are required. Fatigue spectra generation involves creating realistic flight-by-flight sequences of flight conditions and assigning high-fidelity flight loads data to those sequences. This paper details DSTOs development of a novel computer-automated process which pseudo-randomly generates realistic sequences of flight conditions to match a known or assumed usage spectrum.

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Kosenkova, A. V., V. E. Minenko i D. N. Agafonov. "Investigation of the Ballistic Descent Mode for a Maneuverable Lander to the Venus Surface". Herald of the Bauman Moscow State Technical University. Series Mechanical Engineering, nr 4 (133) (sierpień 2020): 42–60. http://dx.doi.org/10.18698/0236-3941-2020-4-42-60.

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At present, various projects to continue fundamental investigations of Venus are considered in Russia and abroad. It means that the issue of developing a landing module to reach the surface of the planet becomes topical, as the module might provide access to the regions most attractive in terms of research. We propose to use a landing module of the lifting body type, which, as compared to a ballistic class module, is not unacceptably complicated in terms of design and at the same time features a lift-to-drag ratio adequate for solving manoeuvring problems arising in the process of descent into the Venusian atmosphere to reach the target landing area. We consider potential descent trajectories available to a landing module of this type, including the possibility of performing a maximum lateral manoeuvre; we took into consideration its long-period trajectories characterised by multiple re-entries into the dense atmosphere and compared these trajectories to the descent trajectory of a conventional ballistic class landing module. We show that using a manoeuvrable craft expands the selection of potential landing regions, as well as reduces loads and broadens the scope of scientific problems to be solved and studies to be undertaken

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Rasuo, B. "Some analytical and numerical solutions for the safe turn manoeuvres of agricultural aircraft – an overview". Aeronautical Journal 111, nr 1123 (wrzesień 2007): 593–99. http://dx.doi.org/10.1017/s000192400000186x.

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Abstract In this paper, a theoretical study of the turn manoeuvre of an agricultural aircraft is presented. The manoeuvre with changeable altitude is analyzed, together with the, effect of the load factors on the turn manoeuvre characteristics during the field-treating flights. The mathematical model used describes the procedure for the correct climb and descent turn manoeuvre. For a typical agricultural aircraft, the numerical results and limitations of the climb, horizontal and descending turn manoeuvre are given. The problem of turning flight with changeable altitude is described by the system of differential equations which describe the influence of the normal and tangential load factors on velocity, the path angle in the vertical plane and the rate of turn, as a function of the bank angle during turning flight. The system of differential equations of motion was solved on a personal computer with the Runge-Kutta-Merson numerical method. Some analytical and numerical results of this calculation are presented in this paper.

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Granvik, Anton. "“Para Hacer un Buen Reentry es Esencial que te Salga Bien el Bottom Primero” – The Presence of English in Portuguese and Spanish Surf Talk". Revista Alicantina de Estudios Ingleses, nr 32 (15.12.2019): 89. http://dx.doi.org/10.14198/raei.2019.32.05.

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Although modern surfing can be traced back to early 20th century Hawaii, only quite recently has surfing become a truly global phenomenon. The aim of this paper is to discuss how the arrival of such a new cultural phenomenon as surfing to the Spanish and Portuguese speaking world is managed linguistically, i.e. to account for how one goes about talking about surfing in Portuguese and Spanish. I propose to investigate how the existing surfing vocabulary in English affects surf talk in Portuguese and Spanish. On the one hand, I will determine which words are incorporated as such and which pieces are incorporated as semantic loans. On the other hand, I will describe what old, native vocabulary is adapted to fit the needs of surf talk. The results indicate that loans are used in roughly 65 per cent of the surfing terms in both Portuguese and Spanish. On a more detailed level, the surfing manoeuvres and conditions, for example, are mostly lexicalized using direct loans, as the terms rentry ‘re-entry’ and bottom ‘bottom turn’ used in the title indicate. Waves, on the other hand, are most often described by means of loan translations, i.e. using Portuguese and Spanish terms reflecting English uses. For example, the goal of any surfer is to ride a tube, tubo in both Portuguese and Spanish. The main difference between the two languages is found in the manoeuvre terms, where Portuguese has introduced several own expressions (e.g. cavada and rasgada) while Spanish relies almost uniquely on direct loans from English.

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Elbanhawi, M., M. Simic i R. Jazar. "Improved manoeuvring of autonomous passenger vehicles: Simulations and field results". Journal of Vibration and Control 23, nr 12 (20.10.2015): 1954–83. http://dx.doi.org/10.1177/1077546315605666.

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This paper describes a novel manoeuvre planning method to attenuate disturbances acting on occupants of autonomous cars as a result of driving behaviour. New research findings suggested that the passengers in autonomous cars might be more prone to motion sickness and thus overall discomfort. The proposed approach is based on a recently developed novel continuous B-spline path smoothing algorithm for car-like steered robots. Two algorithms are designed for urban driving scenarios and steering between two predefined poses. The resulting paths avoid abrupt changes in steering and longitudinal velocity, by maintaining curvature and its high order continuity. We show that this lead to reduced high frequency disturbances in steering and resulting load disturbances on passengers. The presented novel B-spline manoeuvres outperform other planning methods by reducing lateral acceleration and yaw disturbances. New approach was verified by rigorous simulations, numerical and field experimentation. Tests were repeated for a number of different paths and velocities. The reported results are the first spline based parameterisation methods practically applied for autonomous cars planning and re-planning, then validated using both noisy actuation simulations and field experiments.

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Voskuijl, M., D. J. Walker i B. J. Manimala. "Helicopter load alleviation using active control". Aeronautical Journal 112, nr 1137 (listopad 2008): 663–72. http://dx.doi.org/10.1017/s0001924000002633.

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Abstract This paper discusses how structural load objectives can be included in a rotorcraft flight control system design in an efficient and straightforward way using multivariable control techniques. Several research studies have indicated that pitch link loads for various rotorcraft types can reach high or even unacceptable values, both in steady state and maneuvering flight. This is especially the case for high-speed aggressive maneouvers. Pitch link loads at high-speed flight are therefore taken as a case study. A novel longitudinal control system is presented, designed to reduce helicopter pitch-link loads during high-speed longitudinal manoeuvres whilst providing a pitch attitude command attitude hold response type. The design is based on a high-order model of a helicopter representative of the UH-60 Black Hawk. New metrics are presented for the analysis of structural loads that can be used in combination with ADS-33 handling qualities requirements.

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Manimala, B., G. D. Padfield, D. Walker, M. Naddei, L. Verde, U. Ciniglio, P. Rollet i F. Sandri. "Load alleviation in tilt rotor aircraft through active control; modelling and control concepts". Aeronautical Journal 108, nr 1082 (kwiecień 2004): 169–84. http://dx.doi.org/10.1017/s0001924000000087.

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This paper presents the first results from research into active control of structural load alleviation (SLA) for tiltrotor aircraft carried out in the European ‘critical technology’ RHILP project. The importance of and the need for SLA in tiltrotors are discussed, drawing on previous US experience reported in the open literature. The paper addresses the modelling aspects in some detail; hence forming the foundation for both the FLIGHTLAB simulated XV-15 and EUROTILT configurations. The primary focus of attention is the suppression of in-plane rotor yoke loads for pitch manoeuvres in airplane mode; without suppression these loads would result in a very high level of fatigue damage. Multi-variable control law design methods are used to develop controller schemes and load suppression of 80-90% is demonstrated using rotor cyclic control, albeit at a 20-30% performance penalty. However, rotor flapping transients tend to increase by the action of the SLA system. A dual-objective control design approach demonstrates the effectiveness of suppressing both loads and flapping simultaneously.

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Cerrini, Angela, P. Johannesson i Stefano Beretta. "Superposition of Manoeuvres and Load Spectra Extrapolation". Applied Mechanics and Materials 5-6 (październik 2006): 255–62. http://dx.doi.org/10.4028/www.scientific.net/amm.5-6.255.

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To face the increasing demand for long lasting, versatile and performing machines, a detailed analysis of the load conditions is required especially when structural integrity assessment has to be achieved. Usually acquisitions of load histories are shorter than the machine working life and an extrapolation of the signal for the total service life is needed. Traditional methods for load spectra extrapolation are based on conservative choices in terms of worst case scenario. Methods based on extreme value statistics have been developed. The problem addressed in this paper concerns the extrapolation of load histories on a welded boom in which different manoeuvres are superimposed. Different ways of extrapolating the load measurement have been derived, both in time domain and in Markov domain, in order to account for the superposition of bigger and more damaging cycles and smaller cycles caused by two different service operations.

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Scott, P. A., i C. J. Christie. "“Optimal” speed–load combinations for military manoeuvres". International Journal of Industrial Ergonomics 33, nr 1 (styczeń 2004): 63–68. http://dx.doi.org/10.1016/j.ergon.2003.09.003.

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Ma, Kaichao, Changhong Tang, Jianye Zhang, Xiaofei Niu i Qingzhi Fan. "Flight Load Design of Nacelle of Carrier-Based Propeller Transport Aircraft". Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, nr 6 (grudzień 2020): 1249–56. http://dx.doi.org/10.1051/jnwpu/20203861249.

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The carrier-based propeller transport aircraft has a compact layout, where the large nacelle in size and weight is sensitive to propeller slipstream, and thus calls for sophisticated flight load design studies, which are still insufficient considering domestic experience. In detail, the design methods on aerodynamic load, inertial load, gyrostatic moment, as well as studies on design criteria and maneuver simulation technology are shown for a reference aircraft. The design range applied to this nacelle's flight load is firstly determined by understanding and selecting the design criteria. The typical loadcases of the nacelle are derived from aircraft maneuver simulation. The data of pressure distribution under a series of propeller slipstream strengths is obtained by CFD method. The Design Loads and Design Loadcases of the nacelle are calculated and selected. The effects of the propeller slipstream are compared in an example of the increment on aerodynamic load in a maneuver. The results show that the Design Loads of the nacelle are obtained from the abrupt pitching maneuver under the maximum normal load factor (Nz), the yawing maneuver under the Design Dive Speed(VD), and the maximum propeller pull under the maximum landing weight; the transverse loads of the nacelle are dominated by the aerodynamic load, and the normal loads are dominated by the inertial load, in which the inertial force exceeds the aerodynamic force by 4 times under the extreme circumstances. In some manoeuvres or status, the total aerodynamic force of the whole nacelle is increased by above 90% due to propeller slipstream; the front part of the nacelle which is close to the propeller sees a much bigger increment.

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Burlion, L., C. Poussot-Vassal, P. Vuillemin, M. Leitner i T. Kier. "Longitudinal Manoeuvre Load Control of a Flexible Large-Scale Aircraft". IFAC Proceedings Volumes 47, nr 3 (2014): 3413–18. http://dx.doi.org/10.3182/20140824-6-za-1003.01588.

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Suresh, P. S., G. Radhakrishnan i K. Shankar. "Manoeuvre load alleviation using multi-objective optimisation for combat aircraft wing". International Journal of Design Engineering 3, nr 2 (2010): 195. http://dx.doi.org/10.1504/ijde.2010.034864.

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Yu, Dongchi, Lu Wang i Ronald W. Yeung. "Experimental and numerical study of ship-to-ship interactions in overtaking manoeuvres". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475, nr 2225 (maj 2019): 20180748. http://dx.doi.org/10.1098/rspa.2018.0748.

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The study on close-quarter manoeuvring of vessels is of great importance for the safety and efficiency of maritime operations. In this paper, the hydrodynamic interactions between two vessels in moderate-speed overtaking manoeuvres are studied. Computational investigation by free-surface panel method is performed, and the results are assessed against experimental measurements from towing-tank model tests. The influences of overtaking speed and the speed difference between vessels on the hydrodynamic loads are studied. It is found that the free-surface deformation, on account of the blockage effects of the bodies, wave-making properties of the vessels, and the interference of unsteady wave patterns between the vessels, considerably affects the hydrodynamic interactions. In addition, it is also discovered that the influence from the unsteady heave and pitch motions of the hulls on the hydrodynamic loads can be non-negligible. Furthermore, it is found that the slower vessel to be overtaken generally experiences larger loads with more variation than the overtaking vessel. The loads on both vessels become more similar to those of a steady-state di-hull system when the speed difference between vessels is small.

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Lone, Mudassir, Chi Kin Lai, Alastair Cooke i James Whidborne. "Framework for Flight Loads Analysis of Trajectory-Based Manoeuvres with Pilot Models". Journal of Aircraft 51, nr 2 (marzec 2014): 637–50. http://dx.doi.org/10.2514/1.c032376.

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Oyadiji, S. O., A. Ayalew i E. Lai. "Analytical framework for the smooth manoeuvre of wheeled mobile robots traversing obstacles". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, nr 2054 (8.02.2005): 481–507. http://dx.doi.org/10.1098/rspa.2004.1337.

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The aims of this paper are twofold. The first aim is to employ a vectorial approach to model the dynamics of wheeled mobile robots (WMRs), which need to travel over localized surface irregularities. This approach results in compact vectorial equations which are more easily programmable using a symbolic programming software tool. The second aim is to apply the model in conjunction with temporal trajectory functions to compute the traction–force requirements of WMRs traversing obstacles of specified profiles. This model–based approach provides a more robust framework for the development of active control of the motion of WMRs traversing obstacles. It is demonstrated that, during obstacle traversing, a compromise can be achieved between the minimal times of manoeuvre on the one hand and traction force, inertia load and geometrical properties of WMRs and obstacles on the other. The traction force needed to complete the manoeuvre may change sign, necessitating a switch to a braking action. This shift between the traction mode and braking mode of the actuators can be avoided by an appropriate choice of a minimum time of manoeuvre. This study also provides a basis for the selection of an appropriate manoeuvre time based on prior knowledge of the friction characteristics of a traction surface.

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Merchan, Alejandro, i V. J. Clemente-Suárez. "Psychophysiological modifications in an assault infantry manoeuvre using a chemical, biological, radiological and nuclear personal protective equipment". BMJ Military Health 166, nr 2 (17.06.2019): 62–66. http://dx.doi.org/10.1136/jramc-2019-001166.

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IntroductionThe study of the psychophysiological response during combat actions has been poorly researched despite its importance for warfighter training and specific instruction. The aim of the present investigation was to analyse the effect of chemical, biological, radiological and nuclear personal protective equipment (PPE) on the psychophysiological response, mechanical and physical load and fine motor skills of professional soldiers in an endurance infantry manoeuvre.Methods16 soldiers conducted an assault manoeuvre with and without the PEE in separate days. We analysed before and after the manoeuvre the psychophysiological response, fine motor skills, shooting test accuracy and anxiety state.ResultsThe use of PPE produced significantly higher (p<0.05) stress, fatigue, temperature, HR, somatic anxiety and time in middle and high HR zones and significantly lower values in speed average and maximum speed. These findings can be used to improve the training and specific instruction for professionals who require the use of PPE equipment.ConclusionThe use of the PPE suit in an assault manoeuvre produces a decrease in the speed of movement, an increase in HR, body temperature, somatic anxiety and subjective perception of effort.

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Milian, Gabriela, Sorin-Ştefan Biriş i George Ipate. "Modelling behaviour of a partially loaded road tanker with agro-food liquids during the breaking manoeuver". E3S Web of Conferences 112 (2019): 03006. http://dx.doi.org/10.1051/e3sconf/201911203006.

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Longitudinal and lateral liquid sloshing in a partially filled tanker affect the braking performance of the tankers. The movement during braking of the liquid load is determined by the change in the position of the centre of gravity of the load inside the vehicle. Becoming an undesirable phenomenon when analyzing the performance of the vehicle braking manoeuver. In this paper modelling of the behaviour of the cross-section circular tank with baffles, partially filled with liquid agro-food products, was performed, which performs a braking manoeuver. Two different fluids have been used to simulate the sloshing effect of agro-food liquid cargo and study the behaviour of the tank. In to order generate the geometric model of the tank was done by using SolidWorks, and simulating the behaviour of the tank and cargo with agro-food products during the ANSYS-CFX braking manoeuver. A sequence of numerical experiments has been carried out to estimate the pressure developed over the tanker wall and the free surface displacement of the fluids for different fill levels. Simulations with the two liquids and the results obtained were compared to be able to analyze the behaviour of the tank partially filled into a braking manoeuver.

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Stuhlenmiller, Florian, Jochen Schuy, Philipp Beckerle i Stephan Rinderknecht. "A user-specific human-machine interaction strategy for a prosthetic shank adapter". Current Directions in Biomedical Engineering 3, nr 2 (7.09.2017): 493–96. http://dx.doi.org/10.1515/cdbme-2017-0103.

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AbstractFor people with lower limb amputation, a user-specific human-machine interaction with their prostheses is required to ensure safe and comfortable assistance. Especially during dynamic turning manoeuvres, users experience high loads at the stump, which decreases comfort and may lead to long-term tissue damage. Preliminary experiments with users wearing a configurable, passive torsional adaptor indicate increased comfort and safety achieved by adaptation of torsional stiffness and foot alignment. Moreover, the results show that the individual preference regarding both parameters depend on gait situation and individual preference. Hence, measured loads in the structure of the prosthesis and subjective feedback regarding comfort and safety during different turning motions are considered in a user-specific human-machine interaction strategy for a prosthetic shank adaptor. Therefore, the interrelations of gait parameters with optimal configuration are stored in an individual preference-setting matrix. Stiffness and foot alignment are actively adjusted to the optimal parameters by a parallel elastic actuator. Two subjects reported that they experienced appropriate variation of stiffness and foot alignment, a noticeable reduction of load at the stump and that they could turn with less effort.

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Habibi, Hossein, i William O’Connor. "Payload motion control of rotary gantry and luffing cranes using mechanical wave concepts". Transactions of the Institute of Measurement and Control 39, nr 11 (10.05.2016): 1649–62. http://dx.doi.org/10.1177/0142331216644044.

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A new solution is presented to the problem of controlling the motion of a crane’s suspended load through arbitrarily complex, 3D paths through the crane’s manoeuvre space. A generalized boom crane arrangement is considered, so that gantry and luffing arrangements are included as particular cases. Thus the crane’s boom slews about a central, vertical (tower) axis. This boom is either a horizontal gantry with a trolley moving radially along it, from which the load can be winched, or a jib, which can rotate in the vertical plane, with the hoisting cable passing over a pulley attached at its end point. In either case, there are three directly controlled motion variables, the effects of which on the suspended payload’s motion are strongly cross-coupled. The challenge is to enable the payload to follow the desired 3D path as closely as possible during the manoeuvre, and come to rest rapidly at target, by directly controlling these three actuating motions. Thus the controller must achieve position control combined with active swing suppression throughout the manoeuvre and on arrival at the desired end point. A model is developed of the generalized crane for both gantry and luffing crane types. The proposed control strategy is then applied and tested on this model. The controller is based on mechanical wave concepts. When applied to the model, it is shown to be very effective. It is accurate, robust to system changes and actuator limitations, very stable, requires sensing only at the trolley (and not at payload), and is easy to implement.

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38

Suresh, P., G. Radhakrishnan i K. Shankar. "Multi-Objective Optimization Methods Applied for Manoeuvre Load Control on Combat Aircraft wing". International Journal of Aerospace Innovations 2, nr 3 (wrzesień 2010): 189–206. http://dx.doi.org/10.1260/1757-2258.2.3.189.

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Ronald, Janet. "Take a load off with some training in correct moving manoeuvres". Nursing Standard 14, nr 26 (15.03.2000): 29. http://dx.doi.org/10.7748/ns.14.26.29.s52.

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Grabowski, Łukasz, Zbigniew Czyż i Marcin Porzak. "THE STUDY ON LOADS ON AN AIRCRAFT PISTON ENGINE CONTINENTAL MOTORS IOF-240-B5B IN TRAINING FLIGHTS". Transport 33, nr 3 (27.09.2018): 773–78. http://dx.doi.org/10.3846/transport.2018.5467.

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This investigation presents the development of a model of a flight envelope for a piston engine aircraft. The study covers performing necessary tests and measurements of the selected operating parameters of the engine piston and an analysis of the results. The paper describes also a mission and aircraft manoeuvres. This investigation enables us to study loads on an aircraft piston engine, i.e. Continental Motors IOF-240-B5B, mounted in the Liberty XL2 by Liberty Aerospace.

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41

Cox, H. Roxbee. "Problems involving the stiffness of aeroplane wings". Aeronautical Journal 103, nr 1022 (kwiecień 1999): 190–95. http://dx.doi.org/10.1017/s0001924000096470.

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An aircraft may reasonably be said to be structurally safe if it is known that during the manoeuvres which it is likely to perform (i) The stress in no part of the essential structure approaches the failing stress of the material, (ii) It does not become unstable or uncontrollable on account of structural distortion. I intend to discuss in this context the wing structure of the aeroplane. For many years it was felt both in the design and airworthiness approval of the majority of aeroplane wing structures that the main responsibility for attempting to secure the former desideratum could rest upon the determination of the stresses induced in the wing structural material by load systems appropriate to a rigid aeroplane in certain conditions denned by specified combinations of flight attitude, acceleration, and factor of safety. These combinations — familiarly referred to as the C.P. forward, C.P. back, nose-diving and inverted flight cases—are designed to produce for a particular aeroplane a range of steady load systems which is more severe on the structure than the range of load systems corresponding to the manoeuvres contemplated for the aeroplane.

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42

Smith, G. H., J. S. Huntley, R. E. Anakwe, R. J. Wallace i J. E. McEachan. "Tensioning of Prolene reduces creep under cyclical load: relevance to a simple pre-operative manoeuvre". Journal of Hand Surgery (European Volume) 37, nr 9 (24.11.2011): 823–25. http://dx.doi.org/10.1177/1753193411427663.

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A longitudinal stretch or ‘pre-tensioning’ is a method employed by some surgeons to improve the handling characteristics of a suture. We used a tensile tester to assess the effect of pre-tensioning on the mechanical properties of two suture materials (3-0 Prolene and 3-0 Ethibond) commonly used for flexor tendon repair. A cyclical loading programme was used to simulate an early rehabilitation regime. All sutures were subsequently tested to failure (for ultimate tensile strength). The pre-tensioned Prolene sutures showed significantly less creep after cyclical loading in comparison to controls. Conversely pre-tensioning had no measurable effect on the deformation of Ethibond by creep. There was no effect on ultimate tensile strength for either material. The propensity of Prolene to creep (and thereby form a ‘gap’ in tendon repairs) can be reduced by pre-tensioning.

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Canfrán, S., I. A. Gómez de Segura, R. Cediel i J. García-Fernández. "Effects of fluid load on cardiovascular function during stepwise lung recruitment manoeuvre in healthy dogs". Veterinary Journal 197, nr 3 (wrzesień 2013): 800–805. http://dx.doi.org/10.1016/j.tvjl.2013.05.013.

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Vargas, Aldo, Murray Ireland i David Anderson. "Swing-Free Manoeuvre Controller for Rotorcraft Unmanned Aerial Vehicle Slung-Load System Using Echo State Networks". International Journal of Unmanned Systems Engineering 3, nr 1 (1.01.2015): 26–37. http://dx.doi.org/10.14323/ijuseng.2015.3.

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Bhattarai, Aroj, i Manfred Staat. "Modelling of Soft Connective Tissues to Investigate Female Pelvic Floor Dysfunctions". Computational and Mathematical Methods in Medicine 2018 (2018): 1–16. http://dx.doi.org/10.1155/2018/9518076.

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After menopause, decreased levels of estrogen and progesterone remodel the collagen of the soft tissues thereby reducing their stiffness. Stress urinary incontinence is associated with involuntary urine leakage due to pathological movement of the pelvic organs resulting from lax suspension system, fasciae, and ligaments. This study compares the changes in the orientation and position of the female pelvic organs due to weakened fasciae, ligaments, and their combined laxity. A mixture theory weighted by respective volume fraction of elastin-collagen fibre compound (5%), adipose tissue (85%), and smooth muscle (5%) is adopted to characterize the mechanical behaviour of the fascia. The load carrying response (other than the functional response to the pelvic organs) of each fascia component, pelvic organs, muscles, and ligaments are assumed to be isotropic, hyperelastic, and incompressible. Finite element simulations are conducted during Valsalva manoeuvre with weakened tissues modelled by reduced tissue stiffness. A significant dislocation of the urethrovesical junction is observed due to weakness of the fascia (13.89 mm) compared to the ligaments (5.47 mm). The dynamics of the pelvic floor observed in this study during Valsalva manoeuvre is associated with urethral-bladder hypermobility, greater levator plate angulation, and positive Q-tip test which are observed in incontinent females.

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46

Suresh, P. S., G. Radhakrishnan i K. Shankar. "Optimal trends in Manoeuvre Load Control at subsonic and supersonic flight points for tailless delta wing aircraft". Aerospace Science and Technology 24, nr 1 (styczeń 2013): 128–35. http://dx.doi.org/10.1016/j.ast.2011.10.012.

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Kang, Sangmin, Maru Yoon i Myoungho Sunwoo. "Traction control using a throttle valve based on sliding mode control and load torque estimation". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 219, nr 5 (1.05.2005): 645–53. http://dx.doi.org/10.1243/095440705x11059.

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The purpose of an engine-controlled traction control system (TCS) is to regulate engine torque in order to keep the driven wheel slip in a desired range. Engine torque can be regulated by a throttle valve. In this paper, the engine-controlled TCS based on an engine model and estimated load torque by a Luenberger observer is proposed. For this control scheme, the engine model is required for a model-based controller design using sliding mode control. The engine torque controller determines the throttle angle for maintaining the desired manifold pressure to generate engine torque corresponding to the desired wheel torque. Since the load torque is composed of multiple external sources such as friction force, drag force, mechanical losses, and others, load torque estimation is required. The simulation results to various manoeuvres during slippery and split road conditions have showed better acceleration performance and stability of the vehicle with TCS. In addition, the load torque observer has estimated real load torque with little error.

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Arslan, M. Selçuk, i Mert Sever. "Vehicle stability enhancement and rollover prevention by a nonlinear predictive control method". Transactions of the Institute of Measurement and Control 41, nr 8 (18.09.2018): 2135–49. http://dx.doi.org/10.1177/0142331218795200.

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In this study, a nonlinear predictive control method is developed for the active steering control of a sport utility vehicle. The method is tested on a nonlinear mathematical model of an 11-degree-of-freedom vehicle. The system performance is evaluated by considering that the control law must keep the actual yaw rate close to the desired yaw rate and minimizing the vertical load changes at each wheel. The latter is proposed for this work. The vertical load changes play an important role in the dynamics and the stability of the system. The effectiveness of the control method is demonstrated through numerical simulation by using a vehicle model that includes three case studies: rapid lane change at low and high velocities and the fishhook manoeuvre. The results show that the stability of the vehicle is maintained and its rollover propensity is decreased. In addition, the proposed controller is compared with a well-known linear model predictive controller.

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Hussain, K., W. Stein i A. J. Day. "Modelling Commercial Vehicle Handling and Rolling Stability". Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 219, nr 4 (1.12.2005): 357–69. http://dx.doi.org/10.1243/146441905x48707.

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This paper presents a multi-degrees-of-freedom non-linear multibody dynamic model of a three-axle heavy commercial vehicle tractor unit, comprising a subchassis, front and rear leaf spring suspensions, steering system, and ten wheels/tyres, with a semi-trailer comprising two axles and eight wheels/tyres. The investigation is mainly concerned with the rollover stability of the articulated vehicle. The models incorporate all sources of compliance, stiffness, and damping, all with non-linear characteristics, and are constructed and simulated using automatic dynamic analysis of mechanical systems formulation. A constant radius turn test and a single lane change test (according to the ISO Standard) are simulated. The constant radius turn test shows the understeer behaviour of the vehicle, and the single lane change manoeuvre was conducted to show the transient behaviour of the vehicle. Non-stable roll and yaw behaviour of the vehicle is predicted at test speeds >90 km/h. Rollover stability of the vehicle is also investigated using a constant radius turn test with increasing speed. The articulated laden vehicle model predicted increased understeer behaviour, due to higher load acting on the wheels of the middle and rear axles of the tractor and the influence of the semi-trailer, as shown by the reduced yaw rate and the steering angle variation during the constant radius turn. The rollover test predicted a critical lateral acceleration value where complete rollover occurs. Unstable behaviour of the articulated vehicle is also predicted in the single lane change manoeuvre.

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Ariff, O. K., i T. H. Go. "Waypoint Navigation of Small-Scale UAV incorporating Dynamic Soaring". Journal of Navigation 64, nr 1 (26.11.2010): 29–44. http://dx.doi.org/10.1017/s0373463310000378.

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The latest attempts at improving small scale autonomously guided Uninhabited Aerial Vehicles (UAVs) have concentrated around the increase of range and speed. One of these ways is to incorporate dynamic slope soaring manoeuvres as part of the flight path. This is in contrast to most conventional path-planning algorithms where waypoint guidance is merged with terrain avoidance or contour following capability. Additionally, current trajectory optimization techniques are iterative and so have a considerable computational load. The proposed algorithm is based on Dubin's curves, and is therefore optimal by definition. Being non-iterative, it is comparatively a more efficient algorithm. Hence, a key advantage of the proposed technique is that the desired trajectory is generated quickly in real time with minimum computational load while satisfying the spatial constraints of dynamic slope soaring.

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