Journal of Vibration Engineering & Technologies

Kwak, Songhun; Kim, Hakbong; Kim, Kwanghun

doi: 10.1007/s42417-023-00899-4pmid: N/A

PurposeIn this paper, the free vibration and dynamic response of laminated composite wave plate in a thermal environment are investigated by means of the mesh-free strong form method.MethodThe wave plate is divided into several rectangular and cylindrical segments, and each segment is transformed into a square domain or equivalent cylindrical rectangular domain through a coordinate mapping technique to ensure numerical stability. The theoretical formulation of the individual segment is established using Hamilton’s principle in the framework of first-order shear deformation theory (FSDT), and the thermal effects on the wave plate are considered by employing the thermo-elastic theory. The discretized equations are obtained directly from the strong forms of governing equations in which displacement components are approximated by a mes-hfree Tchebychev-radial point interpolation method (TRPIM) shape function. The formulation of the entire wave plate is obtained using coupling conditions between the segments. The harmonic distributed load and stationary/nonstationary stochastic excitation are considered as the external force.ResultsConvergence and verification studies are performed to confirm the reliability and accuracy of the present formulation. Satisfactory agreements are achieved between the numerical results of the proposed method and those from the published literature. Finally, the effect of some parameters on the free vibration and dynamic response of laminated composite wave plate is presented.

Ji, Wenhao; Sun, Wei; Ma, Hongwei; Zhang, Yu; Wang, Dong

doi: 10.1007/s42417-023-00900-0pmid: N/A

PurposeTo perform the vibration reduction optimization of the pipeline system, it is necessary to solve the vibration response of the pipeline system efficiently and accurately. In this paper, a high-precision Super element with few degrees of freedom (DOFs) is newly constructed, and the parametric finite element modeling (PFEM) and vibration reduction optimization methods of the pipeline system are innovatively proposed.MethodA high-precision nonconforming solid (Solid-NC) element is obtained by introducing node-free displacement items into the 8-node conforming solid element. The virtual nodes are constructed, and the coupling element is used to connect the solid and virtual nodes. Furthermore, a Super element is constructed by the statics condensation method, and the stiffness and mass matrices of the Super element are parameterized. The PFEM of the pipeline system is realized by parameterizing the node coordinates, and the rationality of the Super element is verified by the solid model of the pipeline system and the experimental test. Then the genetic algorithm is used to perform vibration reduction optimization.ResultsThe computational efficiencies of the PFEM method are 624.9 times and 151.2 times higher than those of the Solid-NC element in solving the natural characteristics and displacement response, respectively. The integrated displacement response of the optimal pipeline shape is 2.5 times lower than that of the most dangerous pipeline shape.ConclusionsThe Super element can efficiently predict the dynamic characteristics of the pipeline system, which can be used for topology optimization of the pipeline system.

Kumar, Vikash; Kumar, Sanjeev; Sarangi, Somnath

doi: 10.1007/s42417-023-00901-zpmid: N/A

PurposeData preprocessing is one of the key steps in any fault diagnosis process. The real data obtained from machines carry a lot of noise and inferred signals from other parts of the machine or environment. The intensity of this contamination varies with the sampling rate of data acquisition. To filter out these components and enhance the quality of the features generated from these data, several data preprocessing techniques are described in the literature. But the major concerns are the limitations of these techniques and the proper selection of sampling rates for data acquisition.MethodsThis paper presents a comprehensive overview of parametric and non-parametric data preprocessing techniques for gearbox fault diagnosis and how these techniques preserve their properties under different sampling rates. Both analytically simulated signals and experimental signals are used in this work to check the effectiveness of these techniques at different sampling rates.Results and ConclusionsThe obtained results clearly show that data preprocessed by a non-parametric filter contains significantly more information than data preprocessed by a parametric filter or without a filter. Even for a low (affordable) sampling rate, the non-parametric filter works well as compared to the parametric filter and with no filter. The proposed work has potential relevance in the industrial IoT for online condition monitoring of gearboxes.

Rigatos, G.

doi: 10.1007/s42417-023-00902-ypmid: N/A

PurposeDouble-pendulum overhead cranes find use in industry, construction works, and in supply-chain operations. Control and stabilization of the overhead crane and double-pendulum system exhibit elevated difficulty because of nonlinearities and underactuation. In this article, a nonlinear optimal control approach is proposed for the dynamic model of such crane systems.MethodsThe dynamic model of the crane and double-pendulum system undergoes approximate linearization around a temporary operating point that is recomputed at each time step of the control method. The linearization relies on Taylor series expansion and on the associated Jacobian matrices. For the linearized state-space model of the system, a stabilizing optimal (H-infinity) feedback controller is designed.ResultsThis controller stands for the solution to the nonlinear optimal control problem under model uncertainty and external perturbations. To compute the controller’s feedback gains, an algebraic Riccati equation is repetitively solved at each iteration of the control algorithm. The stability properties of the control method are proven through Lyapunov analysis. Finally, to implement state estimation-based control without the need to measure the entire state vector of the overhead crane and double-pendulum system, the H-infinity Kalman filter is used as a robust state estimator.ConclusionsThe proposed nonlinear optimal control method achieves fast and accurate tracking of reference setpoints for all state variables of the double-pendulum overhead crane under moderate variations of the control inputs.

Modak, Krishna; Saravanan, T. Jothi; Rajasekharan, Shanthanu

doi: 10.1007/s42417-023-00903-xpmid: N/A

PurposeThe coupling between axial, transverse shear, and bending deformations is significant for beam-like lattice structures in structural mechanics where beam theory is applied. Likewise, periodic large lattice structures like frames and trusses experience extension-transverse shear-bending coupled vibrations, which the coupled axial-bending Timoshenko beam theory can describe well.MethodsThis paper introduces a general approach using the spectral finite-element method for a single edge notch cracked Timoshenko beam for wave propagation analysis and damage detection. Besides, the present work has developed a spectral element model for the classical coupled axial-bending Timoshenko beam theory and cracked beam theory along with the spectral throw-off elements. The crack introduced is a transverse open and non-propagating crack. The cracked region is discretized into a massless and dimensionless spring element for spectral analysis. The quantity of damage implemented is expressed in crack flexibility based on fracture mechanics, and the compatibility conditions are satisfied at the damage region. The variation in wave propagation analysis is studied in the presence of crack by comparing responses from damaged and undamaged coupled axial-bending Timoshenko beams without coupling coefficients.ResultsThe crack depth and location effects are examined through numerical investigations of the various wave propagation phenomena. The responses collected from different points are presented, and the proper analysis of these responses accurately indicates the damage location. Correspondingly, the investigation for modal analysis is also carried out on the proposed coupled axial-bending Timoshenko beam model with coupling coefficients. The free-vibration analyses for beam models with and without crack conditions are investigated for clamped-free and simply–simply supported boundary conditions. The estimated modal frequencies and mode shapes agree with the existing methods. Thus, the proposed spectral element for the coupled axial-bending cracked Timoshenko beam model is promising for future work with damaged structures with more complex geometry.

Ji, Shubin; Wang, Fuchen; Wang, Jiarui; Wang, Zilu; Wang, Cong; Wei, Yingjie

doi: 10.1007/s42417-023-00904-wpmid: N/A

PurposeThe rich dynamic responses and complex dissipation behaviors of metamaterials with different loading speeds and specific stiffness are investigated. To our knowledge, this work studies systematically for the first time the mutual interaction among these mechanical parameters.MethodsThe metamaterials composed of PCBs (prefabricated curved beams) are modeled as a corresponding NDT (nonlinear damping tandem) model, where the PCB is depicted as a nonlinear spring, the structural mass is simplified as lumped mass, and the energy dissipation is described by equivalent viscous damping.ResultsThe external low-frequency/speed energy can be transformed into high-frequency vibrations via the fully elastic buckling of unstable elements and dissipated, distinguishing it from plastic dissipation. The dissipation process appears to be instantaneous under quasi-static conditions as well as dynamic loadings, which is in sharp contrast to the viscoelastic effect.ConclusionThe dynamic responses and dissipation behaviors depend crucially on the mutual interactions of loading speed and specific stiffness under dynamic loadings.

Xu, Jie; Zhang, Hui; Sun, Chuankai; Shi, Yihan; Shi, Guanchu

doi: 10.1007/s42417-023-00905-9pmid: N/A

PurposeTo improve fault diagnosis efficiency, a multidimensional denoising approach based on tensor decomposition is developed for solving multidimensional signal filtering.MethodsThe monitoring signals are decomposed via truncated high-order singular value decomposition (T-HOSVD) to obtain their factor matrices. With L-curve criterion, the appropriate truncation parameters in the tensor factorization are determined to denoise and reduce dimension of signals. Then, the performance of sequentially truncated HOSVD (ST-HOSVD) is verified to quantify the correlation between the dimension of signal and computation complexity. The proposed ST-HOSVD approach is then applied to reduce noise in torque, current and vibration signals collected on bearing test rig, respectively.ResultsExperimental results show that the performance of the T-HOSVD on signals denoising are poor with the dimension increasing. The ST-HOSVD approach can well remove noise and retain the working status features as much as possible. This tensor-based multidimensional signal filtering will be powerful tool for dealing with heterogeneous and multi-aspect data.ConclusionThe computation complexity of L-curve algorithm will increase sharply with the dimension of signal increasing while optimizing truncated parameters, but that of ST-HOSVD will not vary so much. When the dimension of the tensor model is not too high, the effectiveness of L-curve-T-HOSVD is higher. Otherwise, the computation cost of the ST-HOSVD is relatively lower. Therefore, the priority should be given to the ST-HOSVD for denoising the higher dimensional diagnostic data set about the rolling bearing.

Wellendorf, Axel; von Damnitz, Lukas; Nuri, Abdul Wahab; Anders, Denis; Trampnau, Sebastian

doi: 10.1007/s42417-023-00906-8pmid: N/A

PurposeLangevin transducers are ultrasonic transducers that convert electrical into mechanical energy through the piezoelectric effect. This class of transducers achieves the highest efficiency in their mechanical resonance. Studies have shown that the resonant frequency changes with temperature. The aim of this contribution is to reproduce this temperature-dependence resonance frequency as accurately as possible with FEM simulations.MethodsTherefore, the temperature-dependent resonance behavior of Langevin transducers is examined experimentally. A FEM model is created on the basis of temperature-dependent measured material coefficients. Using parameter correlations and optimization algorithms, the FEM model is fitted and validated by experimental results. Six variants of Langevin transducers are examined in the range from 30 °C to 80 °C with resonance frequencies between 34 and 38 kHz. They differ in three geometries and two materials.ResultsThe experimental results show that the resonance frequencies decrease with increasing temperatures by 5.0–19.4 Hz/°C, depending on the material and geometry. As decisive parameters for the model fitting of the FEM results, three function-dependent stiffness coefficients of the piezoelectric material PZT8 and the Young’s moduli of the metallic materials are determined by parameter correlation.ConclusionThrough the targeted fitting of these function-dependent parameters, the calculation of the resonance frequencies of Langevin transducers can be qualitatively and quantitatively improved, independent of shape and material.

Guo, Jianguo; Tian, Dalong; Huang, He; Guo, Zongyi; Feng, Zhenxin

doi: 10.1007/s42417-023-00907-7pmid: N/A

PurposeA control scheme is presented to attenuate the vibration of the large flexible space structures (LFSS), which includes the optimization of actuator positions and the design of the robust vibration control algorithm. In contrast to the existing literature, the optimization criterion does not depend on the controller parameters, and robust adaptive dynamic programming (RADP) can effectively suppress the vibration of the LFSS under mixed continuous disturbance and model uncertainties.MethodFirst, the optimization criteria of optimal placements of the actuator, which can maximize the actuating efficiency, decoupling input voltage and modal contribution factor, are proposed. On this basis, the adaptive parameter differential evolution (APDE) algorithm is employed to speed up the optimization process. Subsequently, the RADP is designed to enhance the control effect and robustness of the system under external disturbances and model uncertainties. Finally, the RADP-based vibration control performance under optimal and random placement layouts is compared.Results and ConclusionThe effectiveness of the proposed optimization criterion, APDE method and RADP-based vibration control algorithm is verified by simulation. The proposed optimization criteria save the actuator energy consumption and enhance the adaptability of the optimization. The optimal actuator positions can be swiftly identified by the APDE algorithm. In addition, the RADP-based vibration control algorithm improves the control effect, reduces decay time and enhances the robustness of the LFSS under mixed continuous excitation and model uncertainties.

Mufazzal, Sameera; Muzakkir, S. M.; Khanam, Sidra

doi: 10.1007/s42417-023-00908-6pmid: N/A

Purpose The knowledge of spall propagation rate is highly crucial for estimating the remaining useful life of a spalled bearing. The actual mechanism for spall growth is not yet fully understood, however, it is considered that the stress and strain behavior at the spall edge can provide a glimpse of the tendency for crack development and spall progression.MethodThis work presents a new dynamic impact force model for evaluating the fault growth parameters for both localized and extended outer race faults under two possible cases of ball impact, termed as ‘Impact Under Compression (IUC)’ and ‘Free Impact (FI)’.Results and ConclusionThe simulation results revealed that both the radial load and speed favor spall propagation in the case of IUC, whereas the same remains unaffected by the radial load in FI condition and exhibits non-monotonous behavior with increasing speed. Moreover, the defect geometry shows a mixed influence on the behavior of defect growth parameters.