Journal of Sound and Vibration最新文献_第9页

Non-Bloch band theory for time-modulated discrete mechanical systems 时间调制离散机械系统的非布洛赫带理论

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-10-02 DOI: 10.1016/j.jsv.2024.118757

Kei Matsushima, Takayuki Yamada

This study establishes a non-Bloch band theory for time-modulated discrete mechanical systems. We consider simple mass–spring chains whose stiffness is periodically modulated in time. Using the temporal Floquet theory, the system is characterized by linear algebraic equations in terms of Fourier coefficients. This allows us to employ a standard linear eigenvalue analysis. Unlike non-modulated linear systems, the time modulation makes the coefficient matrix non-Hermitian, which gives rise to, for example, parametric resonance, non-reciprocal wave transmission, and non-Hermitian skin effects. In particular, we study finite-length chains consisting of spatially periodic mass–spring units and show that the standard Bloch band theory is not valid for estimating their eigenvalue distribution. To remedy this, we propose a non-Bloch band theory based on a generalized Brillouin zone. This novel approach, the combination of the temporal Floquet theory for time-modulated systems and generalized Brillouin zone, enables the prediction of eigenvalue distribution under open boundary conditions and also quantitative characterization of non-Hermitian skin modes. The proposed theory is verified by some numerical experiments.

本研究为时间调制离散机械系统建立了非布洛赫带理论。我们考虑了刚度在时间上周期性调制的简单质量弹簧链。利用时间 Floquet 理论，该系统由傅里叶系数的线性代数方程表征。这样，我们就可以采用标准的线性特征值分析方法。与非调制线性系统不同的是，时间调制使得系数矩阵非ermitian，从而产生了参数共振、非互易波传输和非ermitian趋肤效应等问题。特别是，我们研究了由空间周期性质量弹簧单元组成的有限长度链，结果表明标准布洛赫带理论无法有效估计其特征值分布。为了弥补这一缺陷，我们提出了一种基于广义布里渊区的非布洛赫带理论。这种新方法结合了用于时间调制系统的时间 Floquet 理论和广义布里渊区，能够预测开放边界条件下的特征值分布，还能定量描述非赫米提集肤模式。一些数值实验验证了所提出的理论。

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引用次数: 0

Multi-task Gaussian Processes based transient aerodynamic load reconstruction for maglev vehicle using acceleration response 基于高斯过程的多任务加速度响应磁悬浮列车瞬态气动载荷重构

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-10-01 DOI: 10.1016/j.jsv.2024.118754

Shuo Hao , Su-Mei Wang , Yi-Qing Ni , Zheng-Wei Chen , Mujib Adeagbo

The accurate estimation of aerodynamic loads is crucial for developing high-speed maglev trains, which can reach speeds of up to 600 km/h. Traditionally, this estimation has been achieved through computational aerodynamic simulation or direct pressure measurement. In this paper, we propose a novel framework for reconstructing transient aerodynamic loads on maglev vehicles using on-board acceleration measurements. In the framework, an inverse mathematical model that correlates the measured acceleration and external aerodynamic loads is derived from a well-calibrated maglev vehicle model. To avoid the ill-posed problem when solving the inverse mathematical model, a multi-task Gaussian Processes method is proposed, in which all reconstructed transient aerodynamic loads are treated as Gaussian Processes and the closed-form posterior distributions of these aerodynamic loads could be calculated. To validate the proposed framework, a set of transient vibration data collected from an operational maglev train passing through a double-track tunnel is utilized for load reconstruction. The results demonstrate that the framework offers a cost-effective and efficient means to obtain aerodynamic loads, highlighting its practical relevance for aerodynamic field testing in the context of evolving high-speed maglev technologies.

高速磁悬浮列车的时速可达 600 公里/小时，准确估算空气动力载荷对于开发高速磁悬浮列车至关重要。传统上，这种估算是通过计算气动模拟或直接压力测量来实现的。在本文中，我们提出了一种利用车载加速度测量重建磁悬浮列车瞬态空气动力载荷的新框架。在这一框架中，我们从一个校准良好的磁悬浮车辆模型中推导出一个逆数学模型，该模型将测量到的加速度和外部空气动力载荷相关联。为了避免在求解逆数学模型时出现求解困难的问题，提出了一种多任务高斯过程方法，将所有重建的瞬态空气动力载荷视为高斯过程，并计算出这些空气动力载荷的闭式后验分布。为了验证所提出的框架，我们利用从通过双轨隧道的运行中磁悬浮列车上收集到的一组瞬态振动数据进行了载荷重建。结果表明，该框架为获取空气动力载荷提供了一种经济高效的方法，突出了其在不断发展的高速磁悬浮技术背景下进行空气动力现场测试的实用性。

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引用次数: 0

HLSM-MIPV Algorithm of unbalance vibration suppression of dual-rotor in contra-rotating propfan HLSM-MIPV 逆旋转风扇双转子不平衡振动抑制算法

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-10-01 DOI: 10.1016/j.jsv.2024.118761

Donghan Wang, Lifang Chen, Yuda Long, Rui Bao, Yabing Sun

The inner and outer rotors of the contra-rotating propfan dual-rotor system, utilizing dual intershaft bearings, exhibit anisotropic support characteristics, whereas the vibration of the dual-rotor system is cross-coupled. This combination makes the identification of unbalanced responses and the efficiency of dynamic balancing challenging. To address this issue, this paper proposes a method for the dynamic balancing of the contra-rotating dual-rotor based on Harmonic Least Squares Method and Modified Initial Phase Vector (HLSM-MIPV). Firstly, a test bench for the contra-rotating dual-rotor system is constructed using two Micro-Electro-Mechanical Systems (MEMS) sensors. Secondly, unbalanced vibration vectors of the dual-rotor are identified using Harmonic Least Squares Method (HLSM). Thirdly, the Harmonic Component Method with the Modified Initial Phase Vector (MIPV-HCM) is introduced to balance the force and couple unbalance under anisotropic stiffness conditions. Finally, dynamic balancing tests on the test bench demonstrate that the MIPV-HCM method achieves an additional vibration reduction of 4 %–17 % compared to the traditional HCM.

使用双轴间轴承的反向旋转推进器双转子系统的内转子和外转子表现出各向异性的支撑特性，而双转子系统的振动是交叉耦合的。这种组合使得不平衡响应的识别和动平衡的效率变得非常具有挑战性。针对这一问题，本文提出了一种基于谐波最小二乘法和修正初始相位矢量（HLSM-MIPV）的反转双转子动平衡方法。首先，利用两个微机电系统（MEMS）传感器构建了反向旋转双转子系统的测试台。其次，使用谐波最小二乘法（HLSM）识别双转子的不平衡振动矢量。第三，引入修正初始相位向量谐波分量法（MIPV-HCM）来平衡各向异性刚度条件下的力和耦合不平衡。最后，试验台上的动态平衡测试表明，与传统的 HCM 相比，MIPV-HCM 方法可额外减少 4 %-17 % 的振动。

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引用次数: 0

Nonlinear Crack-Wave Modulations in Shear Horizontal Wave Propagation for Fatigue Crack Detection 用于疲劳裂纹检测的剪切水平波传播中的非线性裂纹波调制

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-10-01 DOI: 10.1016/j.jsv.2024.118758

Rafał Radecki , Wojciech Trybulec , Mariusz Osika , Wiesław J. Staszewski

The nonlinear interaction of shear horizontal waves with fatigue cracks is investigated for structural damage detection. The focus is on the non-classical modulation effect in the presence of damage. The major principle of the method is explained theoretically and supported by a semi-analytical solution. The method is tested experimentally in aluminium beams with fatigue cracks. A combination of high-frequency ultrasonic and low-frequency vibration shear excitations are introduced to monitored beam components using low-profile piezoceramic shear actuators. Nonlinear vibro-acoustic responses are gathered using laser vibrometry. Vibration excitation frequencies are selected using experimental and numerical modal analysis. A series of vibro-acoustic experiments is performed for fatigue crack detection. The results show that the non-classical nonlinear vibro-acoustic effect – based on shear horizontal wave propagation – can be used for crack detection. In addition, the method also allows for damage localisation.

研究了剪切水平波与疲劳裂纹的非线性相互作用，以用于结构损伤检测。重点是存在损伤时的非经典调制效应。理论上解释了该方法的主要原理，并辅以半解析解。该方法在出现疲劳裂纹的铝横梁上进行了实验测试。使用扁平压电陶瓷剪切激励器，将高频超声波和低频振动剪切激励相结合，引入到受监测的梁部件中。使用激光测振仪收集非线性振动声学响应。通过实验和数值模态分析选择振动激励频率。为疲劳裂纹检测进行了一系列振动声学实验。结果表明，基于剪切水平波传播的非经典非线性振动声学效应可用于裂纹检测。此外，该方法还能进行损伤定位。

引用次数: 0

Dynamic behavior of beam with an elastic foundation under the extended moving load for electromagnetic launch rail-structure 带弹性地基的梁在电磁发射轨道结构的扩展移动载荷下的动态特性

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-09-30 DOI: 10.1016/j.jsv.2024.118756

Bao Zhang , Yong Kou , Ke Jin

The distributed load with loaded area being extended over the whole structure (i.e., the extended moving load) that occurs during the operation of an electromagnetic launch rail-structure, is different from loading cases studied previously such as the concentrated load or distributed load on a finite segment (i.e., the single moving load), or a series of single moving loads in a periodic pattern (i.e., the periodic moving load). In this paper, a nonlinear finite element model is proposed by modeling the rail-structure as a Euler-Bernoulli based beam on an elastic foundation to study the dynamics of rail-beam under such an extended moving load. The proposed model is firstly verified by comparison with the analytical solution for the rail-vibration response under the extended moving load at constant speed, and the model feasibility is further revealed by comparison with the experimental results of rail strain. The significant differences of rail vibration modes are observed between the extended moving load and the single, or periodic moving load. Moreover, the maximum error of the middle of the rail between the linear forcing and nonlinear forcing will decrease with the increase in the foundation elastic modulus, but increases with the increase in the pulse current. Those results will improve our understanding on dynamics of beam under the more comprehensive loading cases.

电磁发射轨道结构在运行过程中会产生分布式载荷，载荷区域扩展至整个结构（即扩展移动载荷），这种载荷不同于以往研究的载荷情况，如有限区段上的集中载荷或分布式载荷（即单一移动载荷），或一系列周期性的单一移动载荷（即周期移动载荷）。本文提出了一种非线性有限元模型，将轨道结构建模为弹性基础上的欧拉-伯努利梁，以研究轨道梁在这种扩展移动载荷下的动力学特性。提出的模型首先通过与匀速延伸移动载荷下钢轨振动响应的解析解进行比较进行验证，并通过与钢轨应变的实验结果进行比较进一步揭示了模型的可行性。扩展移动载荷与单一或周期移动载荷下的钢轨振动模式存在明显差异。此外，随着地基弹性模量的增加，线性加载和非线性加载时钢轨中部的最大误差会减小，但随着脉冲电流的增加，误差会增大。这些结果将有助于我们更好地理解在更全面的加载情况下梁的动力学特性。

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引用次数: 0

A new contact force model for revolute joints considering elastic layer characteristics effects 考虑弹性层特征效应的新旋卷接头接触力模型

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-09-27 DOI: 10.1016/j.jsv.2024.118743

Hongwei Zhang , Zhong Luo , Chao Pang , Chunyang Xu , Sibo Yao

The contact forces generated during the motion of revolute joints with clearances significantly impact the dynamic performance of mechanisms, making it essential to develop an accurate contact force model. Traditional contact models often neglect the influence of elastic layers or assume that the bushing thickness is equal to its radius, which limits their applicability. To address the dynamic contact problem in revolute joints with small clearances, this study employs an improved Winkler elastic foundation model and introduces an elastic layer correction coefficient to refine the static contact model. The model's validity is verified using the finite element method. Building on this, a new contact force model is proposed, incorporating the optimal damping term from multiple continuous contact models. Finally, experimental validation is conducted using the crank-slider mechanism and typical applications in the Variable Stator Vane (VSV) mechanism. The results demonstrate that the proposed contact force model effectively predicts the dynamic characteristics of mechanisms with clearances.

有间隙的滚动轴承在运动过程中产生的接触力会对机械装置的动态性能产生重大影响，因此开发精确的接触力模型至关重要。传统的接触模型通常会忽略弹性层的影响，或假设衬套厚度等于半径，从而限制了其适用性。为了解决具有小间隙的外齿圈接头的动态接触问题，本研究采用了改进的 Winkler 弹性基础模型，并引入了弹性层修正系数来完善静态接触模型。该模型的有效性通过有限元法进行了验证。在此基础上，结合多个连续接触模型的最佳阻尼项，提出了一个新的接触力模型。最后，利用曲柄滑块机构和可变定子叶片（VSV）机构中的典型应用进行了实验验证。结果表明，所提出的接触力模型能有效预测有间隙机构的动态特性。

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引用次数: 0

Tunable low-frequency broadband band gap in nonlinear locally resonant metamaterial inspired by sarcomere structure 受肉瘤结构启发的非线性局部谐振超材料中的可调谐低频宽带隙

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-09-27 DOI: 10.1016/j.jsv.2024.118750

Jiawei Xu , Jianping Jing

Since traditional locally resonant metamaterials (LRMs) cannot achieve a broadband band gap in the low-frequency band, the suppression and isolation of low-frequency broadband vibration has always been a difficult problem in the field of vibration control. Therefore, in this paper, inspired by the structure of the sarcomere, a novel nonlinear LRM is proposed, aiming to open a wider band gap in the low-frequency band. Firstly, a statics model of the nonlinear local resonator (LR) is established to explore the mechanical nonlinear characteristics of the structure with different geometric parameters. And the inflection point fitting method is used to approximate the nonlinear statics model of nonlinear LR. Then a dynamics model was established, the nonlinear dispersion relationship of the infinite periodic system was obtained by Bloch's theorem and l-P perturbation method. And an analytical investigation of the theoretically calculated band gap is conducted through the band gap ratio and relative band gap width. In addition, according to the influence of different structural parameters on the real and imaginary parts of the wave vector, the regulation rules and mechanisms for nonlinear LRM to open low-frequency broadband band gaps are revealed. Finally, the Runge-Kutta method was used to numerically calculate the vibration transmissibility curve of the nonlinear LRM composed of a limited number of nonlinear LRs. And the correctness of the theoretically calculated band gap was verified. The research results provide theoretical support for the application of nonlinear LRMs in the suppression and isolation of low-frequency broadband vibrations.

由于传统的局部谐振超材料（LRM）无法在低频段实现宽带隙，因此抑制和隔离低频宽带振动一直是振动控制领域的难题。因此，本文受肉瘤结构的启发，提出了一种新型非线性 LRM，旨在打开低频段更宽的带隙。首先，本文建立了非线性局部谐振器（LR）的静力学模型，以探索该结构在不同几何参数下的机械非线性特性。并使用拐点拟合方法来近似非线性 LR 的非线性静力学模型。然后建立了动力学模型，利用布洛赫定理和 l-P 扰动法得到了无限周期系统的非线性离散关系。并通过带隙比和相对带隙宽度对理论计算的带隙进行了分析研究。此外，根据不同结构参数对波矢量实部和虚部的影响，揭示了非线性 LRM 打开低频宽带隙的调节规律和机制。最后，利用 Runge-Kutta 方法数值计算了由有限个非线性 LR 组成的非线性 LRM 的振动传递性曲线。并验证了理论计算带隙的正确性。研究结果为非线性 LRM 在抑制和隔离低频宽带振动中的应用提供了理论支持。

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引用次数: 0

An enhanced argument principle algorithm for exact complex transcendental eigenvalue analysis of damped structures 用于阻尼结构精确复超越特征值分析的增强型论证原理算法

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-09-26 DOI: 10.1016/j.jsv.2024.118751

Xiang Liu , Dalun Tang , Xiao Liu

An efficient and reliable complex transcendental eigenvalue algorithm is proposed for exact modal analysis of built-up structures with a generalized damping model. First, the exact damped dynamic stiffness (DDS) formulations for structural elements with frequency-dependent generalized damping models are developed, which can be assembled directly to model complex built-up structures exactly in the frequency domain. An enhanced argument principle algorithm (EAPA) is then proposed to calculate all complex eigenvalues (either distinct or repeated, up to the arbitrarily required precision) within an interested region in the complex plane based on the DDS matrix. The EAPA is essentially enhanced by five newly proposed techniques to improve efficiency, reliability and robustness. In particular, the two-dimensional bisection method, adaptive step-size techniques, data reuse technique, and parallel computation technique improve the efficiency significantly, whereas the pole calculation technique, two-dimensional bisection method, and data reuse technique enhance the reliability greatly. The efficiency, reliability and robustness of the proposed method is demonstrated by finite element method and other algorithms. Moreover, the proposed enhanced argument principle algorithm can also be used as a reliable and efficient zero-finding tool for transcendental functions in general.

本文提出了一种高效可靠的复超越特征值算法，用于对具有广义阻尼模型的建筑结构进行精确模态分析。首先，针对具有频率相关广义阻尼模型的结构元素，提出了精确的阻尼动态刚度（DDS）公式，这些公式可直接用于在频域内对复杂的建筑结构进行精确建模。然后提出了一种增强型参数原理算法（EAPA），可根据 DDS 矩阵计算复平面内感兴趣区域内的所有复特征值（可单独计算或重复计算，精度可任意要求）。为了提高效率、可靠性和鲁棒性，EAPA 通过五种新提出的技术得到了本质上的增强。其中，二维分段法、自适应步长技术、数据重用技术和并行计算技术显著提高了效率，而极点计算技术、二维分段法和数据重用技术则大大提高了可靠性。有限元法和其他算法证明了所提方法的效率、可靠性和鲁棒性。此外，所提出的增强型参数原理算法还可用作一般超越函数的可靠而高效的寻零工具。

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引用次数: 0

The effect of small internal and dashpot damping on a trapped mode of a semi-infinite string 小内阻尼和仪表盘阻尼对半无限弦受困模式的影响

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-09-26 DOI: 10.1016/j.jsv.2024.118749

A.K. Abramian , S.A. Vakulenko , W.T. van Horssen , A. Jikhareva

The effect of small internal and dashpot damping on a trapped mode of a 1D-waveguide, that is, a semi-infinite string on a Winkler elastic foundation, has been investigated. At the edge of the string a mass–spring–damper system is attached. The string is assumed to have an internal damping. Four models for the internal damping are considered: air damping, Kelvin–Voigt damping, local Kelvin–Voigt damping, and damping related to time hysteresis. Depending on the internal damping and the parameters in the formulated problem, it will be shown that the amplitude of a trapped mode of the string can decrease or increase with time.

研究了小的内部阻尼和仪表盘阻尼对一维波导（即温克勒弹性地基上的半无限弦）的陷波模式的影响。在弦的边缘连接了质量-弹簧-阻尼系统。假定弦具有内部阻尼。考虑了四种内部阻尼模型：空气阻尼、开尔文-伏依格特阻尼、局部开尔文-伏依格特阻尼以及与时间滞后相关的阻尼。根据内部阻尼和问题中的参数，可以看出弦的受困模式的振幅会随着时间的推移而减小或增大。

引用次数: 0

Robustness evaluation of acceleration-based early rub detection methodologies with real fluid-induced noise 基于加速度的早期摩擦检测方法与真实流体诱发噪声的鲁棒性评估

IF 4.3 2区工程技术 Q1 ACOUSTICS

Journal of Sound and Vibration

Pub Date : 2024-09-25 DOI: 10.1016/j.jsv.2024.118753

Alejandro Silva , Alejandro Zarzo , Jair León Olivares , Juan Manuel Muñoz-Guijosa

The early detection of rotor-casing rub allows to prevent permanent damage and even catastrophic failure of rotating machines, saving maintenance costs and decreasing downtime. Very often, aeroderivative gas turbines can be monitored only with accelerometers on the casing, which provide signals that contain both stochastic and deterministic noise that masks the vibration measurements. Although real vibration data from turbomachines present a background noise that is neither white nor Gaussian, the rule of thumb is to evaluate the robustness of fault detection under white signal noise, which may lead to estimation errors of such robustness. Here we evaluate and compare the performance of several signal processing methodologies for very early rub detection on accelerometer signals under fluid-induced signal noise due to turbulent fluid excitation. The independence between the fluid-induced vibrations and the rub and unbalance vibration was proved, and experimental data of fluid-induced noise were added as signal noise to clean rub signals. The robustness and sensitivity of rub detection under fluid-induced noise were calculated and compared. This study proves the superiority of reassigned time–frequency analysis methods such as the Wavelet Synchrosqueezed Transform for very early rub detection as compared with traditional time–frequency analysis methods and with the Fourier Transform. To the authors’ knowledge, this is the first time that non-Gaussian fluid-induced signal noise is used to evaluate fault detection performance.

转子与机壳摩擦的早期检测可以防止旋转机器发生永久性损坏甚至灾难性故障，从而节省维护成本并减少停机时间。通常情况下，只能通过机壳上的加速度计来监测航空燃气轮机，而加速度计提供的信号包含随机和确定性噪声，这些噪声会掩盖振动测量结果。虽然透平机的真实振动数据呈现的背景噪声既不是白噪声也不是高斯噪声，但经验法则是评估白信号噪声下故障检测的鲁棒性，这可能会导致这种鲁棒性的估计误差。在此，我们评估并比较了几种信号处理方法在湍流流体激励引起的流体诱导信号噪声下对加速度计信号进行极早期摩擦检测的性能。我们证明了流体诱导振动与摩擦和不平衡振动之间的独立性，并将流体诱导噪声的实验数据作为信号噪声添加到干净的摩擦信号中。计算并比较了流体诱导噪声下摩擦检测的鲁棒性和灵敏度。这项研究证明，与传统的时频分析方法和傅里叶变换相比，小波同步变换等重新分配的时频分析方法在早期摩擦检测方面更具优势。据作者所知，这是首次使用非高斯流体引起的信号噪声来评估故障检测性能。

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引用次数: 0