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lumped parameter modeling of dynamic degradation characteristics of fiber-reinforced composite sheets in thermal environment

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MECHANICS OF ADVANCED MATERIALS AND STRUCTURES 2022年第26期29卷 4698-4710页

作者： Li, Hui Gao, Zhijiang Guan, Jialin Zhao, Jing Xu, Zhonghao Zhao, Siqi Wang, Qingshan Northeastern Univ Sch Mech Engn & Automat Shenyang 110819 Peoples R China Northeastern Univ Key Lab Vibrat & Control Aeroprop Syst Minist Educ Shenyang Peoples R China Northeastern Univ Foshan Grad Sch Foshan Peoples R China Cent South Univ State Key Lab High Performance Complex Mfg Changsha Peoples R China

A lumped parameter model is constructed to accurately predict the dynamic degradation characteristics of the fiber-reinforced composite sheet based on the thermal vibration measurement data. In the modeling process, a multiple-lumped-mass division technique is adopted along the longitudinal and width directions with consideration of thermal degradation on the connective stiffness and damping matrix. By solving the natural frequencies and vibration responses of the structure, a determination method for the key parameters of the model, such as the additional thermal stiffness matrix, the connective stiffness, and the damping coefficients, is proposed. In addition, the constructed model is verified by comparing the theoretical natural frequencies and vibration responses with the experimental results at different degradation time points and temperatures, and the calculation errors are within an acceptable range. Both the theoretical and experimental results reveal a gradual weakened downtrend of natural frequencies and a firstly increasing and then decreasing resonant response phenomenon. Also, some possible reasons for the above complex dynamic degradation phenomenon are provided.

关键词： Composite sheet dynamic degradation characteristic fiber-reinforced composites lumped parameter modeling thermal environment

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Dual cantilever flutter: Experimentally validated lumped parameter modeling and numerical characterization

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JOURNAL OF FLUIDS AND STRUCTURES 2016年 61卷 324-338页

作者： Hobeck, J. D. Inman, D. J. Univ Michigan Dept Aerosp Engn Ann Arbor MI 48109 USA

This paper presents an analytical and experimental investigation of a flow-induced vibration phenomenon referred to as dual cantilever flutter (DCF). The purpose of this research is to introduce the concept of DCF and to help isolate and understand key components that cause it. If unaccounted for, vibration produced by DCF has the potential to cause catastrophic structural damage or unwanted acoustic excitation. This paper includes experimentally validated lumped parameter analytical models for fluid coupling and fluid excitation between two adjacent cantilever beams surrounded by fluid. Results of a nondimensional analysis performed with the DCF model are also given. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Dual cantilever flutter Flow-induced vibration lumped parameter modeling

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Performance measurement and lumped parameter modeling of single server flow lines subject to blocking: An effective process time approach

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COMPUTERS & INDUSTRIAL ENGINEERING 2008年第4期54卷 866-878页

作者： Kock, A. A. A. Wullems, F. J. J. Etman, L. F. P. Adan, I. J. B. F. Nijsse, F. Rooda, J. E. Eindhoven Univ Technol Dept Mech Engn NL-5600 MB Eindhoven Netherlands VDL Steelweld BV Reliabil & Maintainabil Dept NL-4800 DH Breda Netherlands Eindhoven Univ Technol Dept Math & Comp Sci NL-5600 MB Eindhoven Netherlands

The present paper extends the so-called effective process time (EPT) approach to single server flow lines with finite buffers and blocking. The power of the EPT-approach is that it quantifies variability in workstation process times without the need to identify each of the contributing disturbances, and that it directly provides an algorithm for the actual computation of EPTs. It is shown that EPT-realizations can be simply obtained from arrival and departure times of lots, by using sample path equations. The measured EPTs can be used for bottleneck analysis and for lumped parameter modeling. Simulation experiments show that for lumped parameter modeling of flow lines with finite buffers, in addition to the mean and variance, offset is also a relevant parameter of the process time distribution. A case from the automotive industry illustrates the approach. (C) 2007 Elsevier Ltd. All rights reserved.

关键词： blocking discrete event simulation finite buffer capacity lumped parameter modeling performance analysis queuing

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A New lumped parameter modeling for Wind Farm Grounding Measurement Circuits Based on Clamp-on Ground Meters (Apr, 10.1007/s40313-024-01084-y, 2024)

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JOURNAL OF CONTROL AUTOMATION AND ELECTRICAL SYSTEMS 2024年第3期35卷 573-573页

作者： Leal, Alexandre Giacomelli Lazzaretti, Andre E. Lopez-Salamanca, Henry L. Fed Univ Technol Parana UTFPR CPGEI Curitiba PR Brazil Lactec Inst Tecnol Desenvolvimento Curitiba Brazil

Over the years, researchers have proposed models for analyzing and predicting the low-frequency behavior of wind farm grounding systems. The lumped parameter modeling based on circuit theory presents an acceptable compromise between ease of implementation, consumption of computational resources, and accuracy of the results. This paper addresses the impact of mutual couplings between grounding elements in measuring the wind turbines grounding impedance using a clamp-on-ground meter. Furthermore, it proposes a new lumped parameter model for wind farm grounding to include the representation of such effects. In this study, computer simulation uses lumped parameter modeling and electromagnetic field modeling to evaluate turbine grounding impedance readings based on actual wind farm project data. The simulation results, assuming the electromagnetic model as a reference, have demonstrated that the proposed solution can estimate the low-frequency impedance of the measuring loop with an average error of 85.8% lower than existing state-of-the-art models.

关键词： Clamp-on ground meter Electromagnetic field modeling Grounding lumped parameter modeling Wind farm

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Considering land cover and land use (LCLU) in lumped parameter modeling in forest dominated karst catchments

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JOURNAL OF HYDROLOGY 2022年第PartC期612卷

作者： Sivelle, V Jourde, H. Bittner, D. Richieri, B. Labat, D. Hartmann, A. Chiogna, G. Univ Montpellier CNRS HSM IRD Montpellier France Tech Univ Munich Fac Civil Geo & Environm Engn Arcisstr 21 D-80333 Munich Germany Erftverband Dept River Basin Management Erftverband 6 D-50126 Bergheim Germany CNRS UPS IRD CNES Geosci Environm Toulouse GET 14 Ave Edouard Belin F-31400 Toulouse France Tech Univ Dresden Inst Groundwater Management Dresden Germany Univ Innsbruck Inst Geog Innrain 52 A-6020 Innsbruck Austria

lumped parameter modeling approach has been widely applied in karst hydrology for, among other applications, groundwater availability assessment in a context of global change. Nonetheless, such approach generally does not account for land-cover land-use (LCLU) and its impacts on recharge processes. Then, considering a semidistributed recharge constitutes a relevant approach to capture the impacts of LCLU on flow dynamics but also introduce more complexity in the modeling approach. The present study consists of a multiple hydrological model calibration to assess the implication of considering a semi-distributed recharge in a lumped parameter model and focuses on the uncertainty originating by the model structure. The modeling results are discussed to evaluate the trade-off between hydrological model complexity and hydrological model performance. The study focuses on forest dominated karst areas with three karst catchments: Kerschbaum (Lower Austria), Baget (French Pyrenees) and Oeillal (southern France). Considering a semi-distributed recharge gives better performance for both Kerschbaum and Oeillal catchments hydrological models, while no improvement is obtained for Baget catchment. Systematic consideration of LCLU is thus not necessarily worthwhile in karst environmen ts as it can bring contradictory results in terms of hydrological model performance.

关键词： Karst hydrology lumped parameter modeling Land Cover Land Use Recharge

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modeling and Analyzing the Main Modes of an Ultra-Precision Stage with lumped parameter Method

Modeling and Analyzing the Main Modes of an Ultra-Precision ...

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4th International Conference on Modelling,Identification and Control(ICMIC 2012)

作者： Leqing Cui is with the Department of Precision Instruments, Tsinghua University, Beijing 100084 China Yu Zhu is with the Department of Precision Instruments, Tsinghua University, Beijing 100084 China Kaiming Yang is with the Department of Precision Instruments, Tsinghua University, Beijing 100084 China

A lumped parameter model (LPM) is presented to model and analyze the main modes of an ultra-precision stage. The modes of actuator system, measuring system and their summation are discussed based on the analysis of the LPM. Since the measuring system is a coupled and nominal symmetric system, the influence of asymmetry in stiffness to the final visible frequency response functions (FRFs) is examined. Experiments in system identification and modal shape detection are conducted to validate the model.

关键词： lumped parameter modeling main modes model verification

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modeling and Analyzing the Main Modes of an Ultra-Precision Stage with lumped parameter Method

Modeling and Analyzing the Main Modes of an Ultra-Precision ...

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2012 International Conference on Modelling,Identification and Control(建模、辨别与控制国际会议 ICMIC 2012)

作者： Leqing Cui Yu Zhu Kaiming Yang Xin Li Dongdong Yu Department of Precision Instruments TsinghuaUniversityBeijing 100084 China

A lumped parameter model (LPM) is presented to model and analyze the main modes of an ultra-precision *** modes of actuator system, measuring system and their summation are discussed based on the analysis of the *** the measuring system is a coupled and nominal symmetric system, the influence of asymmetry in stiffness to the final visible frequency response functions (FRFs) is *** in system identification and modal shape detection are conducted to validate the model.

关键词： lumped parameter modeling main modes model verification

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Introduction to Mesh Based Generated lumped parameter Models for Electromagnetic Problems using Triangular Elements

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CES Transactions on Electrical Machines and Systems 2023年第1期7卷 21-34页

作者： Haidar Y.Diab Salim Asfirane Nicolas Bracikowski Frédéric Gillon Yacine Amara UniversitéLe Havre Normandie Le Havre76600France Département Génie Industriel et Maintenance Nantes UniversitéSt-Nazaire44602France Ecole Centrale de Lille Hauts-de-France59651France IEEE

This paper is an introduction to mesh based generated reluctance network modeling using triangular *** contributions on mesh based generated reluctance networks using rectangular shaped elements have been published,but very few on those generated from a mesh using triangular *** use of triangular elements is aimed at extending the application of the approach to any shape of modeled *** concepts of the approach are presented in the case of electromagnetic *** procedure for coding the approach in the case of a flat linear permanent magnet machine is *** developed under MATLAB environment are also included.

关键词： lumped parameter modeling Finite element method Mesh Triangular elements Electromagnetic devices modeling

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A lumped parameter core dynamics model for MTR type research reactors under natural convection regime

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ANNALS OF NUCLEAR ENERGY 2013年 56卷 243-250页

作者： Ardaneh, Kazem Zaferanlouei, Salman Univ Tsukuba Dept Comp Sci Grad Sch SIE Tsukuba Ibaraki 3058573 Japan Amirkabir Univ Technol Fac Energy Engn Energy Engn & Phys Dept Tehran Polytech Tehran Iran

On the basis of lumped parameter modeling of both the kinetic and thermal-hydraulic effects, a reasonably accurate simplified model has been developed to predict the dynamic response of MTR reactors following to an unprotected reactivity insertion under natural convection regime. By this model the reactor transient behavior at a given initial steady-state can be solved by a set of ordinary differential equations. The model predictions have an acceptable consent with corresponding results of reactivity insertion transients analyzed in the literature. The inherent safety characteristics of MTR research reactors utilizing natural convection is clearly demonstrated by the expanded model. The safety margin of reactor operating is selected ONB condition and thereby the proposed model determines that any slight increase in the value of $0.73 for inserted reactivity will cause the maximum cladding surface temperature to exceed the ONB condition. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Reactivity insertion MTR research reactor Natural convection lumped parameter modeling

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Development of a Simplified Model for a Distributed-parameter Heat Exchange System for Thermodynamic Principles-Based Control Purposes

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IFAC-PapersOnLine 2018年第13期51卷 396-401页

作者： Pérez-Pirela, M.C. García-Sandoval, J.P. Camacho, O. Departamento de Ingeniería Química Universidad de Guadalajara Calz. Gral. Marcelino García Barragán 1451 GuadalajaraJalisco44430 Mexico Escuela Politécnica Nacional Facultad de Ingeniería Eléctrica y Electrónica Quito Ecuador Universidad de Los Andes Facultad de Ingeniería Mérida Venezuela

In this contribution, a nonlinear lumped-parameter model based on thermodynamic principles is developed to describe the behavior of a distributed-parameter heat exchange system, whose parameters are identified. With the resulting nonlinear lumped-parameter model, a control problem, based on thermodynamic considerations, is proposed to regulate the total entropy production of the heat exchange system, leading to an error dynamics described by a second order nonlinear delayed differential equation. © 2018

关键词： lumped parameter networks Differential equations Distributed parameter control systems Entropy Heat exchangers Identification (control systems) Nonlinear equations Temperature control Delayed differential equations Distributed parameter Distributed parameter systems Entropy production Heat exchange systems lumped parameter modeling lumped parameter systems Temperature profiles

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