Browsing by Author "Yuan, Jie"

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    Automatic interval management for aircraft based on dynamic fuzzy speed control considering uncertainty
    (Elsevier, 2023-07-13) Yuan, Jie; Pei, Yang; Xu, Yan; Li, Xiaochen; Ge, Yuxue
    A novel real-time autonomous Interval Management System (IMS) is proposed to automate interval management, which considers the effect of wind uncertainty using the Dynamic Fuzzy Velocity Decision (DFVD) algorithm. The membership function can be generated dynamically based on the True Air Speed (TAS) limitation changes in real time and the interval criterion of the adjacent aircraft, and combined with human cognition to formulate fuzzy rules for speed adjusting decision-making. Three groups of experiments were conducted during the en-route descent stage to validate the proposed IMS and DFVD performances, and to analyze the impact factors of the algorithm. The verification experimental results show that compared with actual flight status data under controllers’ command, the IMS reduces the descent time by approaching 30% with favorable wind uncertainty suppression performance. Sensitivity analysis shows that the ability improvement of DFVD is mainly affected by the boundary value of the membership function. Additionally, the dynamic generation of the velocity membership function has greater advantages than the static method in terms of safety and stability. Through the analysis of influencing factors, we found that the interval criterion and aircraft category have no significant effect on the capability of IMS. In a higher initial altitude scenario, the initial interval should be appropriately increased to enhance safety and efficiency during the descent process. This prototype system could evolve into a real-time Flight-deck Interval Management (FIM) tool in the future.
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    Efficient computational techniques for mistuning analysis of bladed discs: A review
    (Elsevier, 2016-11-06) Yuan, Jie; Scarpa, Fabrizio; Allegri, Giuliano; Titurus, Branislav; Patsias, Sophoclis; Rajasekaran, Ramesh
    This paper describes a review of the relevant literature about mistuning problems in bladed disc systems, and their implications for the uncertainty propagation associated to the dynamics of aeroengine systems. An emphasis of the review is placed on the developments of the multi-scale computational techniques to increase the computational efficiency for the linear mistuning analysis, especially with the respect to the reduced order modeling techniques and uncertainty quantification methods. The non-linearity phenomena are not considered in this paper. The first two parts describe the fundamentals of the mechanics of tuned and mistuned bladed discs, followed by a review of critical research efforts performed on the development of reduced order rotor models. The focus of the fourth part is on the review of efficient simulation methods for the stochastic analysis of mistuned bladed disc systems. After that, we will finally provide a view of the current state of the art associated to efficient inversion methods for the stochastic analysis, followed by a summary.
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    Impact hammer-based analysis of nonlinear effects in bolted lap joint
    (Katholieke Universiteit Leuven, 2016-10-01) Titurus, Brano; Yuan, Jie; Patsias, S.; Pattison, S.
    This work presents an experimental investigation into the dynamic behavior of a bolted joint beam configuration. The impact hammer is chosen as an alternative to classical harmonic excitation methods. The structural responses are explored for a range of the joint tightening toques and various levels of impulse hammer excitations. A symmetric beam assembly made of two nominally identical steel beams is studied. Symmetric modes are found to be sensitive to the test parameters. For given torque, impact-based varying joint loading conditions are used to induce the nonlinear joint effects. A linear data processing strategy is used to observe the nonlinear behavior indirectly. The dynamic joint behavior is described in the form of the modal frequency-damping ratio performance maps represented by the two-parametric approximating quadratic response surface models. This model maps the joint conditions on the corresponding dynamic characteristics of interest and it will serve as a basis for the parametric linear joint model development
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    Novel frame model for mistuning analysis of bladed disc systems
    (American Society of Mechanical Engineers (ASME), 2017-03-06) Yuan, Jie; Scarpa, F.; Titurus, B.; Allegri, Giuliano; Patsias, S.; Rajasekaran, R.
    The work investigates the application of a novel frame model to reduce the computational cost of the mistuning analysis of bladed disc systems. A full-scale finite element (FE) model of the bladed disc is considered as benchmark. The single blade frame configuration is identified via an optimization process. The individual blades are then assembled by 3D springs, whose parameters are determined via calibration process. The dynamics of the novel beam frame assembly is also compared to those obtained from three state-of-the-art FE-based reduced order models (ROMs): a lumped parameter approach; a Timoshenko beam assembly, and component mode synthesis (CMS) based techniques with free and fixed interfaces. The development of these classical ROMs to represent the bladed disc is also addressed in detail. A methodology to perform the mistuning analysis is then proposed and implemented. A comparison of the modal properties and forced response dynamics between the aforementioned ROMs and the full-scale FE model is presented. The case study demonstrates that the beam frame assembly can predict the variations of the blade amplitude factors with results being in agreement with the full-scale FE model. The CMS based ROMs underestimate the maximum amplitude factor, while the results obtained from beam frame assembly are generally conservative. The beam frame assembly is 4 times more computationally efficient than the CMS fixed-interface approach. This study proves that the beam frame assembly can efficiently predict the mistuning behavior of bladed discs when low order modes are of interest.