Vibration Control Of Structures Research Articles

Latching control for pendulum tuned mass damper: Theoretical analysis and proof-of-concept experiment

Long-period vibrations are very common in various flexible structures, such as high-rise buildings and floating structures. Inspired by latching-based phase optimization in wave energy converters (WECs), a latching control mechanism is applied to realize long-period vibration control. Based on pendulum tuned mass dampers which are a traditional type of vibration control device, an innovative pendulum latched mass damper (PLMD) is proposed, fabricated, and investigated for the first time in this study. First, the concept of PLMD is introduced, and the theoretical model is established. Second, the mechanism and semi-active control strategies for the proposed PLMD are designed. Third, an innovative bench-scale PLMD system is designed and fabricated, wherein the latching control is achieved by using a permanent magnet (PM) brake. Proof-of-concept experiments and numerical simulations are conducted to examine the characteristics, feasibility, and effectiveness of the proposed PLMD. The effects of different latching strategies and time delay are particularly discussed. The proposed latching control mechanism will offer a new and promising solution to remarkably advance long-period vibration control and adaptive-frequency vibration control for various engineering structures.

Parameter optimisation of piezoelectric vibration absorber in composite cylindrical shells: A multi-modal approach to mitigate stochastic vibration

This paper investigates the stochastic vibration mitigation of composite cylindrical shells using multi-modal piezoelectric vibration absorbers (PVAs). A novel semi-analytical method is proposed to analyse the stochastic vibration characteristics of composite cylindrical shells equipped with PVAs. The vibration behaviour under stochastic excitations is determined using the modified Ritz method and the pseudo excitation method (PEM). Compared to the finite element method (FEM), the proposed model greatly enhances efficiency by eliminating the need for repeated modelling and meshing, thereby facilitating the optimisation of PVAs. The effects of piezoelectric patch layout and circuit parameters on PVA performance are examined in detail using the proposed electro-mechanical model. Additionally, a multi-modal PVA design procedure, combining the semi-analytical model with a surrogate model-based optimisation algorithm, is presented. The superior stochastic vibration suppression performance of the multi-modal PVA is demonstrated by comparing the dynamic responses of the composite cylindrical shell without PVA, with single-modal PVA, and with multi-modal PVA. The proposed optimisation procedure offers a valuable approach for the design of multi-modal PVAs for stochastic vibration control of cylindrical structures.

Theoretical and numerical study of the thermo-mechanical coupling effect on the fluid viscous damper

The fluid viscous damper (FVD) is a typical passive energy dissipation device applied to civil engineering structures for vibration control. However, the heat generated during its operation will alter the properties of the fluid, thereby affecting the damping force. This study explores the thermo-mechanical coupling effect on the performance of the FVD. A theoretical model is developed based on fluid dynamics and thermodynamics to reflect the interaction between the real-time damping force and temperature of the FVD. Computational fluid dynamics (CFD) simulations are performed to investigate the impact of the thermo-mechanical coupling effect on the hysteresis performance of the damper and validate the proposed calculation method. The dynamic behavior and vibration mitigation effectiveness of the FVD considering the thermo-mechanical coupling effect are examined based on time history analysis on a single-degree-of-freedom and a multi-degree-of-freedom system. The results indicate that the increased temperature will lead to a reduction in the damping force, while the degraded force will in turn slow the temperature rise. Long-duration and high-intensity excitations can significantly amplify the impact of the thermo-mechanical coupling effect, thus it is essential to be considered in designing dampers for loads in the service stage and major earthquakes. The thermo-mechanical coupling effect on the supplemental damping ratio of the damper is greater than that on structural response control effectiveness, thereby it cannot be neglected when the damping ratio is used as the design criterion for FVDs.

Electromechanical modelling and vibration control analysis of cyclic symmetric structures with a piezoelectric vibration absorber

This study explored the application of piezoelectric vibration absorbers (PVAs) equipped with synthetic circuits for the vibration control of cyclic symmetric structures. A cyclic symmetric electromechanical model (CSEM) integrated with PVAs was introduced to facilitate the design and optimization of the PVAs. This model was formulated analytically based on the circulant matrix theory, and the dynamic response was computed using the complex mode superposition method with explicit consideration of the intrinsic resistance within the PVA. A case study involving a simplified blisk model and an experimental test rig was conducted to validate the proposed CSEM. The validity of the model was confirmed through a comparative analysis of both the natural and dynamic characteristics obtained using the finite element model and experimental results. Furthermore, the impact of synthetic circuit parameters (inductance and negative capacitance values) and the placement of piezoelectric patches on the vibration control performance of PVA were investigated. The results suggested that the optimal inductance coincide with the analytical value, whereas the optimal negative capacitance of the series was slightly greater than the intrinsic capacitance of the patch. Additionally, mounting the piezoelectric patch on the blade root improved the vibration control.

Correction: Structure design and vibration control of vibration reduction boring bar with variable damping

Correction: Structure design and vibration control of vibration reduction boring bar with variable damping

Dynamic Analysis and Vibration Control of Additively Manufactured Thin-Walled Polylactic Acid Polymer (PLAP) and PLAP Composite Beam Structures: Numerical Investigation and Experimental Validation.

This study primarily presents a numerical investigation of the dynamic behavior and vibration control in thin-walled, additively manufactured (AM) beam structures, validated through experimental results. Vibration control in thin-walled structures has gained significant attention recently because vibrations can severely affect structural integrity. Therefore, it is necessary to minimize these vibrations or keep them within acceptable limits to ensure the structure's integrity. In this study, the AM beam structures were made of polylactic acid polymer (PLAP), short carbon fiber reinforced in PLAP (SCFR|PLAP), and continuous carbon fiber reinforced in PLAP (CCFR|PLAP), with 0°|0° layer orientations. The finite element modeling (FEM) of the AM beam structures integrated with macro fiber composite (MFC) was carried out in Abaqus. The initial four modal frequencies of bending modes (BMs) and their respective modal shapes were acquired through numerical simulation. It is crucial to highlight the numerical findings that reveal discrepancies in the 1st modal frequencies of the beams, ranging up to 1.5% compared to their respective experimental values. For the 2nd, 3rd, and 4th modal frequencies, the discrepancies are within 10%. Subsequently, frequency response analysis (FRA) was carried out to observe the frequency-dependent vibration amplitude spectrum at the initial four BM frequencies. Despite discrepancy in the amplitude values between the numerical and experimental datasets, there was consistency in the overall amplitude behavior as frequency varied. THz spectroscopy was performed to identify voids or misalignment errors in the actual beam models. Finally, vibration amplitude control using MFC (M8507-P2) was examined in each kinematically excited numerical beam structure. After applying a counterforce with the MFC, the controlled vibration amplitudes for the PLAP, SCFR|PLAP, and CCFR|PLAP configurations were approximately ±19 µm, ±16 µm, and ±13 µm, respectively. The trend in the controlled amplitudes observed in the numerical findings was consistent with the experimental results. The numerical findings of the study reveal valuable insights for estimating trends related to vibration control in AM beam structures.

Optimization of Vibration Control of Adjacent Buildings Structures by a New Inertial Amplified Mass-Tuned Damper

Optimization of Vibration Control of Adjacent Buildings Structures by a New Inertial Amplified Mass-Tuned Damper

A novel data-driven framework of elastoplastic constitutive model based on geometric physical information

The advantages of data science have inspired the development of data-driven approaches for solving constitutive modeling problems, which have become a new research focus in engineering mechanics. These approaches help fully utilize the information inherent in the data, bypassing the traditional modeling processes.In order to advance the development of Constitutive Model Based on Data-Driven (CMBDD), we introduced a novel framework called the Geometric Physical Information-enhanced Data-Driven ElastoPlastic constitutive model (IDD-EP) under hysteretic loading paths. IDD-EP adopts an ”Encoder-Decoder” framework, with the information transmission between the encoder and decoder facilitated by the ”Geometric Physical Information” proposed in this paper. Specifically, IDD-EP-I, serving as the encoder, extracts Geometric Physical Information from experimental constitutive images, which is then transmitted to the modular data-driven decoder IDD-EP-II, designed based on physical mechanisms, to compute material responses under arbitrary paths. IDD-EP aims to establish a constitutive model relying solely on a single small sample without using deep learning techniques and avoids the challenge of model parameter fitting in classical models through a non-mathematical model design.In addition to discussing the general framework of IDD-EP, this paper specifically demonstrates a specialized version of the IDD-EP framework based on uniaxial buckling-restrained braces (BRBs), which are commonly used in structural vibration control, in order to showcase a specific implementation example of the IDD-EP model. The IDD-EP method in this paper accurately predicts the mechanical response of the BRB using only one constitutive experimental image, without the need to pre-select a base constitutive model or fit model parameters. This innovative approach to IDD-EP opens a new avenue for constitutive modeling of elastoplastic materials and may offer solutions to a wider range of history-dependent constitutive modeling challenges in the future.

Semi-active omnidirectional liquid column vibration absorber with rapid frequency adjustment capability

This paper explores the semi-active omnidirectional liquid column vibration absorber, a unique tuned liquid column damper consisting of multiple circularly distributed columns for the control of vibrations in all lateral directions. Each column features actuator-controlled cells that can trap liquid and adjust column cross-sections, facilitating a rapid shift in natural frequency during operation. Unlike previous semi-active tuned liquid column dampers, this design can modulate its natural frequency without altering the total liquid mass and eliminate the need for overpressure or additional springs. Validation is conducted on a full-scale omnidirectional prototype. However, the trapped liquid mass plays a crucial role in determining the damper’s optimal tuning parameters and affects the resulting restoring force, emphasizing its significance in the design process. This research introduces a comprehensive mathematical model of the absorber, accompanied by a control algorithm, and proposes a corresponding design approach. Moreover, a shape function informed by experimental damping is developed to address complexities arising from geometry and cell arrangements. The focus of the study is the lateral vibration control of high-rise civil engineering structures. Numerical and experimental analyses demonstrate the superior adaptability of the absorber to fluctuating structural properties, marking a significant improvement over its passive counterpart in various loading scenarios.

Experimental characterization and numerical modeling of a frequency-independent viscoelastic damper

Conventional viscoelastic dampers (VED) exhibit significant frequency dependency, leading to variability in stiffness and damping properties at different excitation frequencies, which introduces uncertainties in their design and application in practical engineering. This study addresses this issue by developing a frequency-independent VED through comprehensive experimental characterization and numerical modeling. Four full-scale VEDs were designed and manufactured to explore its mechanical behavior. Cyclic loading tests were carried out under various loading conditions, including different strain amplitudes, loading frequencies, ambient temperatures, and low-cycle fatigue tests. Then, a frequency-independent mechanical model is proposed by combining an energy dissipation element with a nonlinear stiffness element in parallel. Finally, nonlinear dynamic time-history analyses were conducted on a steel frame with and without the VEDs at various ambient temperatures. The experimental results show that the developed VEDs maintain consistent hysteretic behavior across a range of frequencies, exhibit high mechanical stability under varying strain amplitudes and temperatures, and possess excellent recoverability after low-cycle fatigue test. The frequency-independent mechanical model developed in this study accurately simulates the hysteretic response of the developed VEDs, validating its applicability through experimental data. Seismic response analyses demonstrate considerable mitigations in inter-story drift ratios and residual inter-story drift ratios compared to the frame without dampers. These findings highlight the reliability and effectiveness of frequency-independent VEDs in structural vibration control, offering a promising solution for seismic performance enhancement.

Comparative Study of Semi-Active Control Effectiveness of Structures on Soft Soil Using MR Damper: Shaking Table Investigation

The effect of soil-structure interaction (SSI) cannot be neglected in semi-active vibration control of structures located on soft soil. To investigate the mitigating effect of magnetorheological (MR) damper on the semi-active control of structures considering the SSI, shaking table tests were conducted to evaluate the performance of the MR damper-based semi-active control system for structures on soft soil. In addition to a novel fuzzy control method based on online learning deep neural network (OL-DFNN), various control strategies, including passive OFF, passive ON, ON–OFF and deep neural network fuzzy control (DFNN) were systematically evaluated. The test results showed that the OL-DFNN control method exhibited superior adaptability to varying ground motion and structural dynamic characteristics compared to the other control methods. In particular, the OL-DFNN controller effectively mitigated the peak displacement and root mean square displacement, outperforming the passive OFF, passive ON, ON–OFF and DFNN control strategies. The test results highlight the effectiveness of the OL-DFNN control method in addressing the challenges posed by dynamic and time-varying characteristics in structural vibration control systems considering SSI.

Analysis, Modelling and Simulation for the Intelligent Active Vibration Control of a Combined Plant using a New Gyroscopic Combined Actuator Model

There have been several research conducted worldwide on analysis, modelling, and controlling for flexible manipulator architectures. In this paper, one of the most interesting areas in the science of rotational dynamics as the study of spinning solid objects, such as Gyroscopes (G) has been investigated as a new approach for the improvement of the gyroscope non-linear behaviour which controls the magnitude and the direction of the torque separately in the frequency domain by describing a New Graphical Combined Actuator Model (NGCAM) for the Intelligent Active Vibration Control (IAVC) of a Combined Plant (CP) as a linear-nonlinear combined single link Robotics Flexible Manipulator (RFM) structure which rotates in the horizontal plane with two degrees of freedom in order to have a performance assessment and suppressing vibrations. The effect of the parameter variation on the stability and dynamic nonlinear behaviour of the gyroscope in gimbals with a feedback sensor control system has been formed and optimized by the Modified Fuzzy Logic (MFL) algorithm as an artificial intelligence control technique and the Proportional, Integral and Derivative (PID) tuning by the modified Ziegler Nichols (ZN) method. To validate the gyroscope stabilization to be implemented into the RFM for controlling the vibration, the proposed method combines Active Force Control (AFC) technique with Fuzzy Logic (FL) and PID as the (AVC-FL-PID) controller for the NGCAM, CP and RFM by using MATLAB & SIMULINK program is created. For a linear-non-linear combination system, it is better to use a linear-non-linear combination controller. Simulation results illustrate the effectiveness of the proposed strategy which is significantly and quite satisfactory about 25 (%) generally better than compared to the other systems’ performance criteria and is so clear and significant optimization is visible than compared to the other conventional actuators such as PZTs and other control strategies in improvement stabilization and vibration control of RFM structures. The advantages of the proposed method and the possibilities of further improvements are discussed.

Optimizing acoustic black hole structures for vibration control in beams: a comprehensive analysis

Acoustic black holes (ABH) have caught the attention of researchers because of their potential to absorb sound and control vibrations. This study presents an analytical framework that determines reflection coefficients in ABH structures. It focuses on implementing an acoustic black hole with a power-law tapered profile on beams. Moreover, this research investigates how various geometric shapes affect Damping Loss Factor (DLF) coefficients. This helps identify optimal approaches to optimize ABH structures based on specific requirements. The finite element method and a topology optimization solver were used to optimize various parameters systematically. The aim is to reduce weight and response, thereby improving the efficiency of ABH designs, especially in low-frequency insulation applications. The results demonstrate that ABH exhibits excellent performance in suppressing vibrations.

Experimental investigation of particle impact dampers: Vibration reduction and noise levels with varied particle numbers

Structural vibrations present significant challenges in engineering systems, and particle impact dampers (PIDs) have emerged as a promising solution for vibration control. This paper presents a comprehensive experimental investigation on the damping performance of PIDs with varying numbers of particles. The experimental setup involves subjecting a single-degree-of-freedom (SDOF) structure to base motion excitations. Frequency response analysis is conducted to assess the dynamic behavior of the primary system using different PID designs. PIDs with one mass, two masses, three masses and multiple particles are designed and analyzed using the same mass ratio. Additionally, time domain displacement responses of the top of the structure and the base are measured to capture the system's response characteristics. The frequency response analysis reveals the influence of different particle configurations on the system's response amplitude at various frequencies. Interestingly, the results show that a PID with multiple particles exhibits reduced damping performance due to excessive particle-particle collisions. These collisions decrease the energy of the particles, leading to lower velocity before impact. This highlights that the impact itself is the primary source of damping in PIDs, and any other phenomena, such as particle-particle collisions, directly affect the relative velocity before impact. The outcomes demonstrate that an optimal design of PID can reduce vibration amplitude by approximately 85 % with single mass, two masses, and three masses configurations. Conversely, the best-case scenario of PID with multiple particles provides a vibration amplitude reduction of 75 % compared to the absence of a damper. Furthermore, noise data is recorded for all cases, as noise generation is a significant concern associated with PIDs. The results indicate noise magnitudes of 62.5 dB, 70.60 dB, 73.24 dB and 78.64 dB for PIDs with single mass, two masses, three masses, and multiple particles, respectively. Overall, the relationship between the number of particles and damping performance provides valuable insights for optimizing PID designs and ensuring comfortable operation. The findings have broad implications for diverse engineering systems, leading to improved structural performance, reduced noise, and enhanced safety. This study could serve as the basis for several potential applications of PID in structural vibration control with enhanced performance and reduced noise.

Novel rod-sprung-mass model to investigate characteristics of building structural vibration induced by railways

Railway-induced vibrations in building structures require predictions to assess the serviceability. Fundamental properties such as the predominant modes of railway-induced vibrations are critical in structural design and mitigation approaches. However, the existing numerical models are customised to specific buildings. This renders these models unsuitable for broader mechanistic investigations. To address this, this study proposes a rod-sprung-mass (RSM) model to investigate the dynamic behaviour of structures under vertical ground excitations induced by railways. The columns were modelled as axial vibration rods, with each floor suspended on the rod as a sprung mass. The model was validated using a three-story steel frame structure and a five-story concrete structure. Subsequently, the dynamic characteristics of the structures and railway-induced responses were discussed. The structural vertical modes are attributed to the interaction between the columns and slabs, and the structural natural frequencies are outside the frequency range of the individual components. Parametric studies revealed that lower-order structural modes are generally predominant. Under such circumstances, the floor response tends to first decrease and subsequently increase with the floor height. As a result, low-rise buildings exhibit the maximum amplitude on the top floor, whereas the maximum amplitude is on the ground floor for high-rise buildings. Meanwhile, when structural high-order modes become predominant owing to a high-frequency input, the responses of the middle floors intensify, and the peak responses can be altered to the middle floors. This study emphasises the necessity of considering vertical global modes, whereas existing studies have focused mainly on mode shapes on particular floors. The RSM model is an efficient tool for structural design and vibration control.

The Effect of Reynolds Numbers on Flow-Induced Vibrations: A Numerical Study of a Cylinder on Elastic Supports

In the field of fluid dynamics, the Reynolds number is a key parameter that influences the flow characteristics around bluff bodies. While its impact on flow around stationary cylinders has been extensively studied, systematic research into flow-induced vibrations (FIVs) under these conditions remains limited. This study utilizes numerical simulations to explore the FIV characteristics of smooth cylinders and passive turbulence control (PTC) cylinders supported elastically within a Reynolds number range from 0.8 × 104 to 1.1 × 105. By comparing the vibration responses, lift coefficients, and wake structures of these cylinders across various Reynolds numbers, this paper aims to elucidate how Reynolds numbers affect the flow and vibration characteristics of these structures. The research employs images of instantaneous lift changes and vortex shedding across multiple sections to visually demonstrate the dynamic changes in flow states. The findings are expected to provide theoretical support for optimizing structural design and vibration control strategies in high-Reynolds-number environments, emphasizing the importance of considering Reynolds numbers in structural safety and design optimization.

An investigation on seismic performance of the separated fluid inerter base on model experiment and shaking table test

Fluid inerters have gained attention in structural vibration control for their simplicity, durability, high energy dissipation, and significant apparent mass amplification. This study presents an innovative design of a separated fluid inerter, which enhances inertial force, allows for more flexible installation methods, and supports a wider range of connections. A mechanical model is developed and experimentally validated for the separated fluid inerter. The effects of key design parameters on the device's mechanical properties are examined, with a focus on the radii (r1) and length (l) of the helical tube and the radii (r2) of hydraulic cylinder. Theoretical and experimental results confirm the model's reliability and the sensitivity of the device to these parameters. Additionally, a combination of the separated fluid inerter with anti-overturning rolling isolation is applied to a frame structure, and its seismic performance is evaluated through the shaking table test. The results indicate that the separated fluid inerter can effectively reduce the displacement of the isolation layer without significantly increasing the top floor acceleration of the frame structure equipped base isolation (FS-BI).

Dynamic characteristics of a novel inerter-enhanced tuned mass damper for structural vibration control

Dynamic characteristics of a novel inerter-enhanced tuned mass damper for structural vibration control

Structure design and vibration control of vibration reduction boring bar with variable damping

Structure design and vibration control of vibration reduction boring bar with variable damping

Integrated design method for protection against vibration of offshore platform plate structure

The paper integrates the modal avoidance method, pedestal design method, and dynamic vibration absorber theory to investigate vibration control technology for offshore platform plate structures. We develop an integrated design method for vibration suppression by controlling the vibration excitation load, vibration transmission, and vibration energy dissipation. Firstly, a modal avoidance design is implemented to suppress vibration transmission along the propagation path of the plate structure. Subsequently, pedestal optimization is conducted for pedestal structure to attenuate vibration excitation at the input end. Finally, dynamic vibration absorber theory is employed to control dominant vibration frequency responses further and achieve multi-target vibration control. Case simulation results demonstrate that the integrated design method reduces the acceleration vibrations level at 113.75, 145.61, and 153 Hz, and this method could guide multi-objective vibration control in offshore platform plate structures.