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Article
Publication date: 16 August 2021

Zhiguang Cheng, Behzad Forghani, Zhenbin Du, Lanrong Liu, Yongjian Li, Xiaojun Zhao, Tao Liu, Linfeng Cai, Weiming Zhang, Meilin Lu, Yakun Tian and Yating Li

This paper aims to propose and establish a set of new benchmark models to investigate and confidently validate the modeling and prediction of total stray-field loss inside…

126

Abstract

Purpose

This paper aims to propose and establish a set of new benchmark models to investigate and confidently validate the modeling and prediction of total stray-field loss inside magnetic and non-magnetic components under harmonics-direct current (HDC) hybrid excitations. As a new member-set (P21e) of the testing electromagnetic analysis methods Problem 21 Family, the focus is on efficient analysis methods and accurate material property modeling under complex excitations.

Design/methodology/approach

This P21e-based benchmarking covers the design of new benchmark models with magnetic flux compensation, the establishment of a new benchmark measurement system with HDC hybrid excitation, the formulation of the testing program (such as defined Cases I–V) and the measurement and prediction of material properties under HDC hybrid excitations, to test electromagnetic analysis methods and finite element (FE) computation models and investigate the electromagnetic behavior of typical magnetic and electromagnetic shields in electrical equipment.

Findings

The updated Problem 21 Family (V.2021) can now be used to investigate and validate the total power loss and the different shielding performance of magnetic and electromagnetic shields under various HDC hybrid excitations, including the different spatial distributions of the same excitation parameters. The new member-set (P21e) with magnetic flux compensation can experimentally determine the total power loss inside the load-component, which helps to validate the numerical modeling and simulation with confidence. The additional iron loss inside the laminated sheets caused by the magnetic flux normal to the laminations must be correctly modeled and predicted during the design and analysis. It is also observed that the magnetic properties (B27R090) measured in the rolling and transverse directions with different direct current (DC) biasing magnetic field are quite different from each other.

Research limitations/implications

The future benchmarking target is to study the effects of stronger HDC hybrid excitations on the internal loss behavior and the microstructure of magnetic load components.

Originality/value

This paper proposes a new extension of Problem 21 Family (1993–2021) with the upgraded excitation, involving multi-harmonics and DC bias. The alternating current (AC) and DC excitation can be applied at the two sides of the model’s load-component to avoid the adverse impact on the AC and DC power supply and investigate the effect of different AC and DC hybrid patterns on the total loss inside the load-component. The overall effectiveness of numerical modeling and simulation is highlighted and achieved via combining the efficient electromagnetic analysis methods and solvers, the reliable material property modeling and prediction under complex excitations and the precise FE computation model using partition processing. The outcome of this project will be beneficial to large-scale and high-performance numerical modeling.

Article
Publication date: 18 March 2022

Donghai Wang, Wei Sun, Zhihui Gao and Hui Li

In many cases, the external pipelines of aero-engine are subjected to random excitation. The purpose of this paper is to reduce the vibration response of the pipeline system…

Abstract

Purpose

In many cases, the external pipelines of aero-engine are subjected to random excitation. The purpose of this paper is to reduce the vibration response of the pipeline system effectively by adjusting the hoop layout.

Design/methodology/approach

In this paper, a spatial pipeline supported by multi-hoops is taken as the object, the methods of solution of the vibration response of the pipeline system by using pseudo excitation and hoop layouts optimization with amplitude reduction of vibration response as the goal are presented. First, the finite element model of the spatial pipeline system is presented. Then, an optimization model spatial pipeline is established. Finally, a case study is carried out to prove the rationality of the random vibration response analysis of the pipeline system. Furthermore, the proposed optimization model and genetic algorithm are applied to optimize the hoop layout.

Findings

The results show that the maximum response variance after optimization is reduced by 32.8%, which proves the rationality of the developed hoop layout optimization method.

Originality/value

The pseudo excitation method is used to solve the vibration response of aero-engine pipeline system, and the optimization of the hoop layout for aero-engine spatial pipelines under random excitation to reduce random vibration response is studied systematically.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 8 May 2018

Dongdong He, Qiang Gao and Wanxie Zhong

The purpose of this paper is to propose an accurate and efficient numerical method for determining the dynamic responses of a tensegrity structure consisting of bars, which can…

Abstract

Purpose

The purpose of this paper is to propose an accurate and efficient numerical method for determining the dynamic responses of a tensegrity structure consisting of bars, which can work under both compression and tension, and cables, which cannot work under compression.

Design/methodology/approach

An accurate time-domain solution is obtained by using the precise integration method when there is no cable slackening or tightening, and the Newton–Raphson scheme is used to determine the time at which the cables tighten or slacken.

Findings

Responses of a tensegrity structure under harmonic excitations are given to demonstrate the efficiency and accuracy of the proposed method. The validation shows that the proposed method has higher accuracy and computational efficiency than the Runge–Kutta method. Because the cables of the tensegrity structure might be tense or slack, its dynamic behaviors will exhibit stable periodicity, multi-periodicity, quasi-periodicity and chaos under different amplitudes and frequencies of excitation.

Originality/value

The steady state response of a tensegrity structure can be obtained efficiently and accurately by the proposed method. Based on bifurcation theory, the Poincaré section and phase space trajectory, multi-periodic vibration, quasi-periodic vibration and chaotic vibration of the tensegrity structures are predicted accurately.

Details

Engineering Computations, vol. 35 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 3 January 2017

Peyman Rafiee, Golta Khatibi and Michael Zehetbauer

The purpose of this paper is to provide an overview of the major reliability issues of microelectromechanical systems (MEMS) under mechanical and environmental loading conditions…

1022

Abstract

Purpose

The purpose of this paper is to provide an overview of the major reliability issues of microelectromechanical systems (MEMS) under mechanical and environmental loading conditions. Furthermore, a comprehensive study on the nonlinear behavior of silicon MEMS devices is presented and different aspects of this phenomenon are discussed.

Design/methodology/approach

Regarding the reliability investigations, the most important failure aspects affecting the proper operation of the MEMS components with focus on those caused by environmental and mechanical loads are reviewed. These studies include failures due to fatigue loads, mechanical vibration, mechanical shock, humidity, temperature and particulate contamination. In addition, the influence of squeeze film air damping on the dynamic response of MEMS devices is briefly discussed. A further subject of this paper is discussion of studies on the nonlinearity of silicon MEMS. For this purpose, after a description of the basic principles of nonlinearity, the consequences of nonlinear phenomena such as frequency shift, hysteresis and harmonic generation and their effects on the device performance are reviewed. Special attention is paid to the mode coupling effect between the resonant modes as a result of energy transfer because of the nonlinearity of silicon. For a better understanding of these effects, the nonlinear behavior of silicon is demonstrated by using the example of Si cantilever beams.

Findings

It is shown that environmental and mechanical loads can influence on proper operation of the MEMS components and lead to early fracture. In addition, it is demonstrated that nonlinearity modifies dynamic response and leads to new phenomena such as frequency shift and mode coupling. Finally, some ideas are given as possible future areas of research works.

Originality/value

This is a review paper and aimed to review the latest manuscripts published in the field of reliability and nonlinearity of the MEMS structures.

Details

Microelectronics International, vol. 34 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 4 March 2022

Wang Jianhong

The purpose of this paper is to extend the authors’ previous contributions on aircraft flutter model parameters identification. Because closed-loop condition is more widely used…

Abstract

Purpose

The purpose of this paper is to extend the authors’ previous contributions on aircraft flutter model parameters identification. Because closed-loop condition is more widely used in today’s practice, a closed-loop stochastic model of the aircraft flutter test is constructed to model the aircraft flutter process, whose input–output signals are all corrupted by the observed noises. Through using a rational transfer function, the equivalent property between the aircraft flutter model parameters and polynomial coefficients is established, and then the problem of aircraft flutter model parameters identification is turned to one closed-loop identification problem. An iterative identification algorithm is proposed to identify the unknown polynomial coefficients, being benefit for the latter flutter model parameter identification. Furthermore, as the closed-loop output corresponds to the flutter amplitude, so from the point of the minimization with respect to the variance of the closed-loop output, the optimal input signal and optimal feedback controller are all derived to achieve the zero flutter, respectively, for example, the optimal input spectrum and the detailed form for optimal feedback controller.

Design/methodology/approach

First, model parameter identification for aircraft flutter is reviewed as one problem of parameter identification and this aircraft flutter model corresponds to one closed-loop stochastic model, whose input signal and output are corrupted by external noises. Second, for aircraft flutter closed-loop statistical model with statistical noise, an iterative identification algorithm is proposed to identify the unknown model parameters. Third, from the point of minimizing with respect to the variance of the closed-loop output, the optimal input signal and optimal feedback controller are all derived to achieve the zero flutter, respectively, for example, the optimal input spectrum and the detailed form for optimal feedback controller.

Findings

This aircraft flutter model corresponds to one closed-loop stochastic model, whose input signal and output are corrupted by external noises. Then, identification algorithm and optimal input signal design are studied for aircraft flutter model parameter identification with statistical noise, respectively. It means the optimal input signal and optimal feedback controller are useful for the aircraft flutter model parameter identification within the constructed new closed-loop stochastic model.

Originality/value

To the best of the authors’ knowledge, this problem of the model parameter identification for aircraft flutter is proposed by their previous work, and they proposed many identification strategies to identify these model parameters. This paper proposes a new closed-loop stochastic model to construct the aircraft flutter test, and some related topics are considered about this closed-loop identification for aircraft flutter model parameter identification in the framework of closed-loop condition.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 7
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 June 2021

Wang Jianhong

The purpose of this paper considers optimal input signal design for flutter model parameters identification, as input signal is the first step during the whole identification…

Abstract

Purpose

The purpose of this paper considers optimal input signal design for flutter model parameters identification, as input signal is the first step during the whole identification process. According to the constructed flutter stochastic model with observed noises, separable least squares identification and set membership identification are proposed to identify those unknown model parameters for statistical noise and unknown but bounded noise, respectively. The common trace operation with respect to the asymptotic variance matrix is minimized to solve the power spectral for the optimal input signal in the framework of statistical noise. Moreover, for the unknown bout bounded noise, the radius of information, corresponding to the established parameter uncertainty interval, is minimized to give the optimal input signal.

Design/methodology/approach

First, model identification for aircraft flutter is reviewed as one problem of parameter identification and this aircraft flutter model corresponds to one stochastic model, whose input signal and output are corrupted by external noises. Second, for aircraft flutter statistical model with statistical noise, separable least squares identification is proposed to identify the unknown model parameters, then the optimal input signal is designed to satisfy one given performance function. Third, for aircraft flutter model with unknown but bounded noise, set membership identification is proposed to solve the parameter set for each unknown model parameter. Then, the optimal input signal is designed by applying the idea of the radius of information with unknown but bounded noise.

Findings

This aircraft flutter model corresponds to one stochastic model, whose input signal and output are corrupted by external noises. Then identification strategy and optimal input signal design are studied for aircraft flutter model parameter identification with statistical noise and unknown but bounded noise, respectively.

Originality/value

To the best knowledge of the authors, this problem of the model parameter identification for aircraft flutter was proposed by their previous work, and they proposed many identification strategies to identify these model parameters. This paper proposes two novel identification strategies and opens a new subject about optimal input signal design for statistical noise and unknown noise, respectively.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 26 August 2014

Shanming Wang, Yonghong Xia, Shaogang Huang, Arui Qiu and Xiangheng Wang

In order to keep the advantages of PM generators and eliminate its disadvantage – difficulty in regulating the magnetic field, hybrid excitation is an effective way. The purpose…

Abstract

Purpose

In order to keep the advantages of PM generators and eliminate its disadvantage – difficulty in regulating the magnetic field, hybrid excitation is an effective way. The purpose of this paper is to propose a novel way to achieve hybrid excitation by use of tooth harmonic field.

Design/methodology/approach

Unlike weakening the tooth harmonics field and EMF in traditional machines, in this paper the tooth harmonics field is proposed to form a novel hybrid excitation permanent magnet synchronous generator (HEPMSG).

Findings

The generation mechanism of tooth harmonic electromotive force (EMF) of rotor winding is introduced, and its influencing factors are discussed in detail. The matching design of tooth harmonic winding and field winding for maximum output field current of tooth harmonic excitation system is analyzed.

Practical implications

This machine can achieve not only effective adjustment of the air-gap magnetic field, but also elimination of the brushes and slip rings.

Originality/value

Unlike weakening the tooth harmonics field and EMF in traditional machines, in this paper the tooth harmonics filed is proposed to form a novel hybrid excitation PM synchronous generator. This machine can achieve not only effective adjustment of the air-gap magnetic field, but also elimination of the brushes and slip rings.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 March 2016

Yonghong Xia, Junbo Liu, Bo Xu and Hongjian Wu

The purpose of this paper is to propose a novel hybrid excitation permanent magnet synchronous generator (HEPMSG) utilizing tooth harmonic for excitation, the structural features…

Abstract

Purpose

The purpose of this paper is to propose a novel hybrid excitation permanent magnet synchronous generator (HEPMSG) utilizing tooth harmonic for excitation, the structural features and operation principle of which are also described.

Design/methodology/approach

To obtain the operation performance quickly, this paper derives the mathematical model of the machine system represented by circuit, and analyzes the operation mode of rectifier circuit in the tooth harmonic excitation system, then the standard state equations for each operation mode are obtained. Combining the inductance parameter of this machine with the load resistance and inductance, the armature current waveform, the field current waveform and tooth harmonic winding current waveform are obtained by using the numerical method to solve the standard state equation.

Findings

Comparing with the experimental results, the availability of the principle and the validity of the model of the machine system are verified.

Practical implications

This HEPMSG is a new brushless self-excited and self-regulated generator, which is suitable for an independent power source.

Originality/value

Unlike the existing hybrid excitation permanent magnet machine, this HEPMSG utilized the inherent tooth harmonic EMF of the rotor to adjust the air-gap magnetic field of the permanent magnet machine.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 11 November 2020

Duncai Lei, Xiannian Kong, Siyu Chen, Jinyuan Tang and Zehua Hu

The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and…

326

Abstract

Purpose

The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and the influences of the system factors including mesh stiffness, error excitation and torque on the dynamic transmission error (DTE).

Design/methodology/approach

A simple lumped parameters dynamic model of a gear pair considering time-varying mesh stiffness, backlash and unloaded STE excitation is developed. The STE is calculated from the measured tooth profile deviation under the unloaded condition. A four-square gear test rig is designed to measure and analyze the DTE and vibration responses of the gear pair. The dynamic responses of the gear transmission are studied numerically and experimentally.

Findings

The predicted numerical DTE matches well with the experimental results. When the real unloaded STE excitation without any approximation is used, the dynamic response is dominated by the mesh frequency and its high order harmonic components, which may not be result caused by the assembling error. The sub-harmonic and super-harmonic resonant behaviors are excited because of the high order harmonic components of STE. It will not certainly prevent the separations of mesh teeth when the gear pair is under the condition of high speed and heavy load.

Originality/value

This study helps to improve the modeling method of the dynamic analysis of spur gear transmission and provide some reference for the understanding of the influence of mesh stiffness, STE excitation and system torque on the vibration behaviors.

Details

Engineering Computations, vol. 38 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 6 November 2017

Xiaojun Zhao, Fanhui Meng, Zhiguang Cheng, Lanrong Liu, Junjie Zhang and Chao Fan

This paper aims to investigate an efficient approach to model the electromagnetic behaviors and predict stray-field loss inside the magnetic steel plate under 3D harmonic

Abstract

Purpose

This paper aims to investigate an efficient approach to model the electromagnetic behaviors and predict stray-field loss inside the magnetic steel plate under 3D harmonic magnetization conditions so as to effectively prevent the structural components from local overheating and insulation damage in electromagnetic devices.

Design/methodology/approach

An experimental setup is applied to measure all the magnetic properties of magnetic steel plate under harmonic excitations with different frequencies and phase angles. The measurement and numerical simulation are carried out based on the updated TEAM Problem 21 Model B+ (P210-B+), under the 3D harmonic magnetization conditions. An improved method to evaluate the stray-field loss is proposed, and harmonic flux distribution in the structural components is analyzed.

Findings

The influence of the harmonic order and phase angle on the stray-field loss in magnetic steel components are noteworthy. Based on the engineering-oriented benchmark models, the variations of stray-field losses and magnetic field distribution inside the magnetic components under harmonic magnetization conditions are presented and analyzed in detail.

Research limitations/implications

The capacity of the multi-function harmonic source, used in this work, was not large enough, which limits the magnetization level. Up to now, further improvements to increase the harmonic source capacity and investigations of the electromagnetic behaviors of magnetic steel components under multi-harmonic and DC-AC hybrid excitations are in progress.

Originality/value

To accurately predict the stray-field loss in magnetic steel plate, the improved method based on the combination of magnetic measurement and numerical simulation is proposed. The effects of the frequency and phase angle on the stray-field loss are analyzed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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