Article
Engineering, Aerospace
Yayun Shi, Shun He, Gaowei Cui, Gang Chen, Yan Liu
Summary: This study investigates the quenching of limit cycle oscillation (LCO) in a supercritical airfoil (NLR 7301) considering freeplay in transonic viscous flow. Computational Fluid Dynamics (CFD) based on Navier-Stokes equations is used to calculate transonic aerodynamic forces. A loosely coupled scheme with steady CFD and an efficient graphic method is developed to obtain the aerodynamic preload. The LCO quenching is observed based on nonlinear dynamic aeroelastic response obtained using a time marching approach.
CHINESE JOURNAL OF AERONAUTICS
(2023)
Article
Mechanics
Marco Grifo, Vincenzo Gulizzi, Alberto Milazzo, Andrea Da Ronch, Ivano Benedetti
Summary: A novel computational approach combining a variable-order kinematics structural model with Computational Fluid Dynamics (CFD) is proposed for static aeroelastic analysis of metal and composite wings in transonic flows. This approach aims to develop a flexible computational aeroelastic framework that can accurately describe flow separation, viscous phenomena, and shock waves in high subsonic, transonic, or supersonic regimes.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
Sai Vishal, Ashwad Raaj, Chandan Bose, J. Venkatramani
Summary: This study investigates the synchronization characteristics of a pitch-plunge aeroelastic system under the influence of coupled structural free-play and dynamic stall-induced aerodynamic non-linearities. The results show that free-play nonlinearity plays a dominant role in the dynamical transition when attached flow is present. The onset of dynamic stall is found to be crucial in bifurcation scenarios at high flow speed regimes.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Liuyue Bai, Zhigang Wu, Chao Yang
Summary: This study provides novel perspectives on the nonlinear aeroelastic characteristics of all-movable fins with freeplay nonlinearities. An unsteady aerodynamic model based on the second-order piston theory considering thickness effects is employed. A discrete scanning method using the describing function method is established for systems with multiple freeplay nonlinearities to solve limit-cycle oscillations (LCOs) and avoid solution loss. The influence of support stiffness and freeplay size ratio on the system's dynamical response is analyzed.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Civil
Henrik Skyvulstad, Tommaso Argentini, Alberto Zasso, Ole Oiseth
Summary: The research discusses the nonlinear wind load models for bridge decks and uses experimental data to study the observed nonlinearities. The study introduces a response-surface model for force prediction and identifies typical nonlinear characteristics such as mean drift and harmonic distortion. The findings help gain insight into the nonlinearity of the problem and refine modeling approaches for future work.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2021)
Article
Engineering, Mechanical
Matthieu Parenteau, Eric Laurendeau
Summary: This paper develops an aeroelastic framework based on the Unsteady Vortex Lattice Method suitable for compressible, transonic, and viscous unsteady flows. By extending UVLM to the nonlinear frequency domain, applying sectional corrections, and implementing an approximation of the retarded time, the framework is capable of capturing strong nonlinear Limit Cycle Oscillation behaviors at high Mach numbers.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Engineering, Aerospace
Kun Ye, Pengze Xie, Xu Zhan, Liuzhen Qin, Zhengyin Ye
Summary: This study investigates the aerodynamic interference on the transonic flutter characteristics of biplane wings placed close to each other. The results show that the interference accelerates the airflow on the upper surface of the elastic airfoil, leading to a subsonic dip phenomenon and earlier appearances of transonic dip and S-shape flutter boundary. The interference also widens the S-shape flutter boundary.
Article
Engineering, Mechanical
Michael Candon, Oleg Levinski, Hideaki Ogawa, Robert Carrese, Pier Marzocca
Summary: This study introduces a signal processing framework based on nonlinear system identification methods for rapid diagnosis of structural freeplay in modern aircraft systems to meet the requirements of PHM technology. Experimental validation demonstrates that the framework is capable of extracting the location and magnitude information of structural freeplay and making consistent predictions over multiple maintenance cycles.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Multidisciplinary Sciences
Mehmet Emin Aktas, Thu Nguyen, Sidra Jawaid, Rakin Riza, Esra Akbas
Summary: This report presents a novel method to identify critical higher-order interactions in complex networks and compares the performances of the generalized centrality measures to demonstrate the effectiveness of higher-order interactions. Experimental results suggest that higher-order interactions play more critical roles than edges, and the proposed methods are promising in identifying critical higher-order interactions.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Aerospace
A. L. Gaitonde, D. P. Jones, J. E. Cooper
Summary: This paper presents a new efficient method for constructing an approximately balanced aerodynamic reduced order model using frequency domain and computational fluid dynamics data. The method shows good accuracy and substantial reduction in calculation time for both inviscid and viscous flow.
AERONAUTICAL JOURNAL
(2022)
Article
Physics, Applied
V. Yu Borynskyi, D. M. Polishchuk, A. K. Melnyk, A. F. Kravets, A. Tovstolytkin, V Korenivski
Summary: The study explores the spin dynamics in nanodisk arrays of synthetic-antiferromagnets with Py/NiCu/Py trilayers. It demonstrates the capability to control resonance modes through micromagnetic simulations and the transition to a single-layer nanodisk array below the Curie temperature of the spacer. Multilayering of nanoarrays adds tunable GHz functionality for various applications such as magnetic metamaterials and magnonic crystals.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Mechanical
Arvid Trapp, Peter Wolfsteiner
Summary: This work introduces a new estimator for higher-order spectra, which assesses the non-linear, non-Gaussian, or non-stationary properties of systems through cross-frequency correlation. The method demonstrates a better bias-variance trade-off, computational efficiency, flexibility, and simplicity.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Multidisciplinary Sciences
Kai Bai, Liang Fang, Tian-Rui Liu, Jia-Zheng Li, Duanduan Wan, Meng Xiao
Summary: In recent years, higher-order exceptional points (HOEPs) have shown significant potential in detection applications. However, they have faced challenges such as strict parameter requirements, limited resolution, and noise. In this study, by exploring the consequence of nonlinear gain saturation, we propose a feasible scheme to overcome these difficulties and demonstrate an 'exceptional nexus' (EX) with an ultra-enhanced signal-to-noise ratio (SNR) in two coupled resonators. Our findings advance the understanding of nonlinear non-Hermitian systems and reduce the practical difficulty in EP sensing, offering new possibilities for applications.
NATIONAL SCIENCE REVIEW
(2023)
Article
Mathematics, Applied
Sid Ahmed Berraih, Sidi Mohammed El Amine Debbal, Nour Elhouda Baakek Yettou
Summary: Cardiovascular diseases are the leading cause of morbidity and mortality worldwide, with heart disorders mainly affecting heart valves and blood flow. A computer-aided technique based on PCG signals with higher-order spectra analysis (HOS) has been proposed to assess and differentiate cardiac pathology through the analysis of non-linear phonocardiogram signals.
APPLIED MATHEMATICS AND COMPUTATION
(2021)
Article
Engineering, Aerospace
Shengye Wang, Xiang Fu, Xiaogang Deng
Summary: This paper proposes two measures for computing turbulent flows using higher-order methods in computational fluid dynamics (CFD): introducing lambda-scale instead of the commonly used co, and proposing a geometric-conservation-preservation negativity-correction method based on high-order nonlinear schemes. Numerical tests with real-life compressible flows demonstrate the robustness and accuracy of these methods.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Michael Candon, Oleg Levinski, Hideaki Ogawa, Robert Carrese, Pier Marzocca
Summary: This study introduces a signal processing framework based on nonlinear system identification methods for rapid diagnosis of structural freeplay in modern aircraft systems to meet the requirements of PHM technology. Experimental validation demonstrates that the framework is capable of extracting the location and magnitude information of structural freeplay and making consistent predictions over multiple maintenance cycles.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Multidisciplinary
Dongyang Chen, Chaojie Gu, Pier Marzocca, Jiadong Yang, Guang Pan
Summary: The vibration characteristics of rotating blades are crucial for the structural reliability of rotating machinery. This paper proposes the Transfer Matrix Method of Multibody System (MSTMM) to study the vibration characteristics of single rotating beam and rotor-stator coupled system. The influence of blade rotation is illustrated by computing the vibration characteristics at varying rotating speeds. The modeling process is simple and rapid, and can be applied to compute the bending-torsional frequencies of helicopter and wind turbine blades.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Engineering, Mechanical
Michael Candon, Marco Esposito, Haytham Fayek, Oleg Levinski, Stephan Koschel, Nish Joseph, Robert Carrese, Pier Marzocca
Summary: Over the past decade, the ideologies surrounding Structural Health Monitoring (SHM) have shifted drastically within the aerospace engineering disciplines, predominantly due to rapid advancements in machine intelligence. The next generation SHM system, known as Prognostics and Health Management (PHM), focuses on proactive condition-based maintenance, forecasting, and prognostics, advancing towards Digital Twin technology.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Review
Chemistry, Analytical
Michael J. Scott, Wim J. C. Verhagen, Marie T. Bieber, Pier Marzocca
Summary: In recent years, the use of sensor technologies and digitalization in aircraft sustainment and operations has enhanced the ability to detect, diagnose, and predict the health of aircraft. Predictive maintenance and related concepts have gained increasing attention in research, but limitations still exist in terms of research methodology definition and the lack of review papers on military applications. This review paper aims to address these gaps by providing a systematic review focused on the operations and sustainment of fixed-wing defence aircraft.
Article
Engineering, Manufacturing
Chenxi Peng, Pier Marzocca, Phuong Tran
Summary: This paper presents a novel honeycomb structure inspired by TPMS architecture, which has tuneable mechanical responses. Experimental and numerical results show that the proposed structure has higher elastic modulus and plateau stress compared to traditional honeycomb structures. Additionally, by introducing density gradient or a hybrid structure with different topologies, the mechanical response of the structure can be tuned.
VIRTUAL AND PHYSICAL PROTOTYPING
(2023)
Article
Geochemistry & Geophysics
Kathiravan Thangavel, Dario Spiller, Roberto Sabatini, Pier Marzocca, Marco Esposito
Summary: Climate action, specifically regarding wildfires, is important for sustainable development. The increasing frequency and size of forest fires in recent years pose threats to forests, urban areas, and human lives. Real-time/near real-time monitoring of these catastrophic events is necessary, and the Distributed Satellite System (DSS) can effectively fulfill this purpose. This research examines the feasibility of utilizing DSS for wildfire surveillance and proposes a model and scenario prototype for a satellite artificial intelligence (AI) system to provide prompt alerts and actions.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2023)
Article
Mechanics
Arturo Delgado-Gutierrez, Pier Marzocca, Diego Cardenas-Fuentes, Oliver Probst, Alejandro Montesinos-Castellanos
Summary: This article presents an efficient implementation of the GPU-accelerated single-step and simplified lattice Boltzmann method for curved fluid domains. The model accurately predicts macroscopic flow variables in realistic scenarios, and the computational performance is significantly faster than other simulations reported in the literature.
Article
Environmental Sciences
Kathiravan Thangavel, Dario Spiller, Roberto Sabatini, Stefania Amici, Sarathchandrakumar Thottuchirayil Sasidharan, Haytham Fayek, Pier Marzocca
Summary: This study focuses on the application of space-borne technology for accurate fire detection. By training convolutional neural networks, the feasibility of classifying wildfires in space missions is demonstrated. Onboard data processing proves to be beneficial for disaster management and climate change mitigation, enabling timely alerts and rapid responses.
Article
Chemistry, Multidisciplinary
Alessandro Polla, Giacomo Frulla, Enrico Cestino, Raj Das, Pier Marzocca
Summary: This article presents a numerical methodology for simulating advanced composite joints. The methodology is able to accurately predict the progressive damage and failure analysis of the joints under different loads. It offers a rational approach to designing damage-tolerance composite structures.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Multidisciplinary
Dongyang Chen, Rui Xu, Zhida Yuan, Guang Pan, Pier Marzocca
Summary: Two-dimensional fluid-structure coupling dynamic models were established to study the vortex-induced vibration of single- and double-cylinder systems with an airfoil. The accuracy of the simulation models was verified by comparing with experimental data. The influence of the cylinders' positions on the airfoil's aerodynamic forces was investigated, and vorticity and streamline diagrams were used to analyze their effects. It was found that small oscillating cylinders placed near the airfoil's leading edge could effectively control flow separation and improve the airfoil's lift-to-drag ratio, especially at high angles of attack. The ability of a single oscillating cylinder to control the flow gradually decreased post stall condition, while the double cylinders' ability increased.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Chemistry, Analytical
Kathiravan Thangavel, Dario Spiller, Roberto Sabatini, Stefania Amici, Nicolas Longepe, Pablo Servidia, Pier Marzocca, Haytham Fayek, Luigi Ansalone
Summary: Recent developments in Distributed Satellite Systems (DSS) have increased mission value by enabling spacecraft cluster reconfiguration and incremental satellite additions or updates. Trusted Autonomous Satellite Operation (TASO) is made possible by the integrity features of Artificial Intelligence (AI), allowing for autonomous reconfiguration and communication between spacecraft through an Inter-Satellite Link (ISL). AI, sensing, and computing technologies also enable trusted autonomy in intelligent DSS (iDSS) operations, improving Space Mission Management (SMM) with state-of-the-art optical sensors.
Article
Engineering, Aerospace
Kathiravan Thangavel, Pablo Servidia, Roberto Sabatini, Pier Marzocca, Haytham Fayek, Santiago Husain Cerruti, Martin Espana, Dario Spiller
Summary: This research explores the potential applicability of Synthetic Aperture Radar (SAR) and Distributed Satellite Systems (DSS) for Maritime Domain Awareness (MDA) operation. A robust AT-InSAR Formation Flying concept is proposed to combine several along-track baseline observations effectively for single-pass interferometry. Simulation results support the feasibility of implementing this acquisition mode with low-thrust actuation suitable for electric propulsion and autonomous orbit control. A constellation of this formation concept is also proposed to improve repeatability and the benefits of DSS.
Article
Engineering, Aerospace
Alessandro Polla, Giacomo Frulla, Enrico Cestino, Raj Das, Pier Marzocca
Summary: This study presents a coupled thermo-mechanical modeling technique and its numerical simulations for analyzing carbon fiber-reinforced composite panels subjected to high-velocity impact. By determining the essential numerical parameters through a physical-based approach, the trial-and-error calibration process is minimized. New observations regarding modeling techniques, energy transfer, and damage mechanisms in target plates are offered.
Article
Thermodynamics
Sean Samson, Phuong Tran, Pier Marzocca
Summary: Triply Periodic Minimal Surfaces (TPMS) are increasingly popular as heatsinks and heat exchanger topologies due to their inherent geometries that provide larger heat transfer surface areas and smooth flow paths. However, more research is needed to understand how design parameters, such as cell size, affect flow and heat transfer performance. This study investigates the effects of cell size and porosity on TPMS gyroid sheets as heatsinks in turbulent flow, and finds that convective performance is independent of cell size but greatly influenced by porosity. The results show significant improvements in thermal resistance, Nusselt number, and enhancement-to-losses compared to a reference fin heatsink.
APPLIED THERMAL ENGINEERING
(2023)
Article
Mechanics
A. Avetisyan, K. Ghazaryan, P. Marzocca
Summary: This paper investigates the stability of a multi-span finite length beam compressed on periodic rigid and elastic supports. The transfer matrix method combined with Bloch-Floquet's approach is used to analyze the stability of the compressed beam. Various boundary value stability problems are considered analytically and numerically, and compared with the infinite beam model. The results show that the periodic infinite beam model agrees well with the results of the finite length beam with equidistant rigid and elastic supports when the number of spans is more than six. It is also demonstrated that elastic supports significantly enhance the stability of the multi-span beam.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Engineering, Mechanical
Xuanen Kan, Yanjun Lu, Fan Zhang, Weipeng Hu
Summary: A blade disk system is crucial for the energy conversion efficiency of turbomachinery, but differences between blades can result in localized vibration. This study develops an approximate symplectic method to simulate vibration localization in a mistuned bladed disk system and reveals the influences of initial positive pressure, contact angle, and surface roughness on the strength of vibration localization.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Zimeng Liu, Cheng Chang, Haodong Hu, Hui Ma, Kaigang Yuan, Xin Li, Xiaojian Zhao, Zhike Peng
Summary: Considering the calculation efficiency and accuracy of meshing characteristics of gear pair with tooth root crack fault, a parametric model of cracked spur gear is established by simplifying the crack propagation path. The LTCA method is used to calculate the time-varying meshing stiffness and transmission error, and the results are verified by finite element method. The study also proposes a crack area share index to measure the degree of crack fault and determines the application range of simplified crack propagation path.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Rongjian Sun, Conggan Ma, Nic Zhang, Chuyo Kaku, Yu Zhang, Qirui Hou
Summary: This paper proposes a novel forward calculation method (FCM) for calculating anisotropic material parameters (AMPs) of the motor stator assembly, considering structural discontinuities and composite material properties. The method is based on multi-scale theory and decouples the multi-scale equations to describe the equivalence and equivalence preconditions of AMPs of two scale models. The effectiveness of this method is verified by modal experiments.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Hao Zhang, Jiangcen Ke
Summary: This research introduces an intelligent scheduling system framework to optimize the ship lock schedule of the Three Gorges Hub. By analyzing navigational rules, operational characteristics, and existing problems, a mixed-integer nonlinear programming model is formulated with multiple objectives and constraints, and a hybrid intelligent algorithm is constructed for optimization.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Jingjing He, Xizhong Wu, Xuefei Guan
Summary: A sensitivity and reliability enhanced ultrasonic method has been developed in this study to monitor and predict stress loss in pre-stressed multi-layer structures. The method leverages the potential breathing effect of porous cushion materials in the structures to increase the sensitivity of the signal feature to stress loss. Experimental investigations show that the proposed method offers improved accuracy, reliability, and sensitivity to stress change.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Benyamin Hosseiny, Jalal Amini, Hossein Aghababaei
Summary: This paper presents a method for monitoring sub-second or sub-minute displacements using GBSAR signals, which employs spectral estimation to achieve multi-dimensional target detection. It improves the processing of MIMO radar data and enables high-resolution fast displacement monitoring from GBSAR signals.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xianze Li, Hao Su, Ling Xiang, Qingtao Yao, Aijun Hu
Summary: This paper proposes a novel method for bearing fault identification, which can accurately identify faults with few samples under complex working conditions. The method is based on a Transformer meta-learning model, and the final result is determined by the weighted voting of multiple models.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xiaomeng Li, Yi Wang, Guangyao Zhang, Baoping Tang, Yi Qin
Summary: Inspired by chaos fractal theory and slowly varying damage dynamics theory, this paper proposes a new health monitoring indicator for vibration signals of rotating machinery, which can effectively monitor the mechanical condition under both cyclo-stationary and variable operating conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Hao Wang, Songye Zhu
Summary: This paper extends the latching mechanism to vibration control to improve energy dissipation efficiency. An innovative semi-active latched mass damper (LMD) is proposed, and different latching control strategies are tested and evaluated. The latching control can optimize the phase lag between control force and structural response, and provide an innovative solution to improve damper effectiveness and develop adaptive semi-active dampers.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Menghao Ping, Xinyu Jia, Costas Papadimitriou, Xu Han, Chao Jiang, Wang-Ji Yan
Summary: Identification of non-Gaussian processes is a challenging task in engineering problems. This article presents an improved orthogonal series expansion method to convert the identification of non-Gaussian processes into a finite number of non-Gaussian coefficients. The uncertainty of these coefficients is quantified using polynomial chaos expansion. The proposed method is applicable to both stationary and nonstationary non-Gaussian processes and has been validated through simulated data and real-world applications.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Lei Li, Wei Yang, Dongfa Li, Jianxin Han, Wenming Zhang
Summary: The frequency locking phenomenon induced by modal coupling can effectively overcome the dependence of peak frequency on driving strength in nonlinear resonant systems and improve the stability of peak frequency. This study proposes the double frequencies locking phenomenon in a three degrees of freedom (3-DOF) magnetic coupled resonant system driven by piezoelectricity. Experimental and theoretical investigations confirm the occurrence of first frequency locking and the subsequent switching to second frequency locking with the increase of driving force. Furthermore, a mass sensing scheme for double analytes is proposed based on the double frequencies locking phenomenon.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Kai Ma, Jingtao Du, Yang Liu, Ximing Chen
Summary: This study explores the feasibility of using nonlinear energy sinks (NES) as replacements for traditional linear tuned mass dampers (TMD) in practical engineering applications, specifically in diesel engine crankshafts. The results show that NES provides better vibration attenuation for the crankshaft compared to TMD under different operating conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Wentao Xu, Li Cheng, Shuaihao Lei, Lei Yu, Weixuan Jiao
Summary: In this study, a high-precision hydraulic mechanical stand and a vertical mixed-flow pumping station device were used to conduct research on cavitation signals of mixed-flow pumps. By analyzing the water pressure pulsation signal, it was found that the power spectrum density method is more sensitive and capable of extracting characteristics compared to traditional time-frequency domain analysis. This has significant implications for the identification and prevention of cavitation in mixed-flow pump machinery.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xiaodong Chen, Kang Tai, Huifeng Tan, Zhimin Xie
Summary: This paper addresses the issue of parasitic motion in microgripper jaws and its impact on clamping accuracy, and proposes a symmetrically stressed parallelogram mechanism as a solution. Through mechanical modeling and experimental validation, the effectiveness of this method is demonstrated.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Zhifeng Shi, Gang Zhang, Jing Liu, Xinbin Li, Yajun Xu, Changfeng Yan
Summary: This study provides useful guidance for early bearing fault detection and diagnosis by investigating the effects of crack inclination and propagation direction on the vibration characteristics of bearings.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
