Experimental results show that mechanical behaviors of viscoelastic dampers are greatly affected by ambient temperature. Neglecting the ambient temperature effect will lead to an inaccurate seismic evaluation on viscoelastically damped structures. This study investigates the ambient temperature effect on the seismic performance of viscoelastically damped structures. An efficient algorithm is proposed

One of the performance-limiting factors in the design of robust controllers for active magnetic bearing systems is the fact that the controller needs to be robust to the gyroscopic effects, that is rotational speed-dependent dynamics of the system. Studies in the literature show that better performance and stability can be achieved when gyroscopic effects are explicitly handled by a cross-feedback

In this study, a robust adaptive controller is designed to be used in an active tuned mass damper system that can be used to damp undesired vibrations that occurred on the multistory buildings during the earthquake. To realize the controller design, all of the system parameters are assumed to be unknown, and the adaptive structure of the designed controller is obtained by designing adaptive compensation

In crane systems, lifting, carrying and lowering the load from one place have different dynamic effects on the system. One of these dynamic effects is the moving load problem caused by the movement of the load on the crane system. With the increasing technology in recent years, production speeds have increased. For this reason, it has made the requirements for fast-running cranes mandatory for the

A mathematical discussion is introduced to describe the receiver coil characterizing a nuclear magnetic resonance for imaging, starting from a general shape of the conductor. A set of different inductance calculations have been introduced, varying the shape of the conductor. The inductance calculation led to a general expression of the magnetic field of a single coil characterized by a rectangular

Natural frequency and damping behavior of three-layer cylindrical shells with a viscoelastic core layer and functionally graded face layers are studied in this article. Using functionally graded face layers can reduce the stress discontinuity in the face–core interface that causes a catastrophic failure in sandwich structures. The viscoelastic layer is expressed using a fractional-order model, and

Position controllers are used for free motion, whereas force controllers are used for constrained motion of robotic manipulators. The hybrid controller switches between position and force control modes depending on whether the manipulator is in contact with the environment. To improve production efficiency, the velocity of contact between the manipulator and environment is not set to zero. However

In the monitoring of structural systems, the use of multiple high-end sensors may prove to be economically prohibitive. The alternative approach would be to use fewer devices capable of moving across the span of the structural system. In the proposed approach, a velocity sensor that is able to move across the spatial domain and obtain point-wise velocity measurements is combined to a novel dynamic

The purpose of this article is to study the coupling effects of support stiffness on geometric scaling factor powers of the rotor-bearing system and predict vibration characteristics of a prototype by scaled models accurately. Associated to the least-squares–based similitude method, the discrete iteration method proposed evaluates the estimated scaling laws under variable (instable) powers and further

The hedge algebras theory has the potential to make significant applications in the field of computational intelligence. The purpose of the present study is to improve the control performance of the hedge algebras–based controller by tuning its control rules and apply the hedge algebras–based controller using the tuned rule base in vibration control of structures. The authors propose a “tuning coefficient”

A two-scale concurrent topology optimization method based on the couple stress theory is proposed for maximizing structural fundamental eigenfrequency. Because of the fact that the classical mechanics theory cannot reveal the size effect because of neglecting the influence of microstructure, the theory of couple stress including the microscopic properties of materials can be used to describe the size

In this article, a multi-crack detection method, which is based on natural frequency changes and the concept of modal strain energy, is for the first time developed for the general cross-section swept tapered wings under coupled bending-torsional vibration and applied to the solid and thin-walled airfoil cross-section wings. The presented method is able to handle the problems with an unknown number

Repetitive controllers are widely used in rotor systems of magnetically suspended control moment gyro, which are responsible for suppressing harmonic current because of sensor runout and mass imbalance of the rotor. However, the rotation frequency of the rotor is not constant in industrial applications, and it is likely to fluctuate around the rotation frequency, which greatly affects the suppression

Time delay is a critical and unavoidable problem in real-time hybrid simulation. An accurate and effective compensation method for time delay is necessary for the safety of real-time hybrid simulation and the reliability of test results. Generally, a model-based compensation method can be adopted, which is derived from the identified transfer function by assuming the latter can accurately represent

Collision among multiple structures is a major source of noise in industry. To gain a more comprehensive understanding of the collision noise radiated by the impact structures, the collision noise of multiple spheres is measured by an impact device and simulated by a validated numerical model. The numerical model of collision noise radiation is constructed with the explicit nonlinear LS-DYNA3D and

In this new study, we investigate the motion of a forced mass-spring-damper in a vertical position. First, the classical Lagrangian as well as the classical Euler–Lagrange equation of motion are constructed. Then the fractional Euler–Lagrange equation is derived by extending the classical Lagrangian in the fractional sense. In this extension, a new form of the fractional derivative is employed including

This article deals with a novel adaptive robust controller for uncertain nonlinear systems relying on a proportional–integral–derivative-type nonsingular fast terminal sliding mode control. In this nonsingular proportional–integral–derivative-type terminal sliding mode controller nonsingular fast terminal sliding mode control, the nonsingular fast terminal sliding mode control sliding surface is modified

Controlling multimode vibrations using a single actuator and a single sensor is challenging. Most researchers use multiactuators and multisensors to control multimode structural vibrations. In the present work, a multimode delayed feedback control using a single actuator and a single sensor, both attached at the top surface of a simply supported thin plate, is developed. The linear equations of motion

Synchronous vibration is a major obstacle to the stable operation of rotating machineries. In previous studies, active control methods were developed to compensate for synchronous vibration using actuators, such as an active magnetic bearing or a piezo actuator. Adaptive feedforward cancellation is another well-known control method and is used to compensate for the synchronous vibration in the actual

This article considers the problem of adaptive neural network control via command filtering for incommensurate fractional-order chaotic permanent magnet synchronous motors with full-state constraints and parameter uncertainties. First, a neural network state observer based on a K-filter is established to reconstruct unmeasured feedback information. Then, the command filtered technology is used to overcome

In this research, the effect of rail vehicle carbody’s flexural modes on the ride comfort of an example high-speed railway vehicle is investigated. The vehicle is modeled as a rigid multi-body system, where the rigid body vertical, longitudinal, pitch, and roll degrees of freedom of the carbody and bogie frames and the rigid body vertical and roll degrees of freedom of the wheelsets are considered

The present article deals with the vibration and damping characteristics of functionally graded carbon nanotubes reinforced hybrid composite skewed shell structure in different hygrothermal conditions. Carbon nanotube reinforced polymer as a matrix phase and carbon fibre as a reinforcing phase are used, and carbon fibre is graded with uniform distribution along the thickness direction for the shell

Dealing with torsional vibrations and stick–slip oscillations of a drill string system is a challenging engineering task in the oil drilling process because of the harmful and costly consequences of such vibrations. In this article, the drill string system is modeled using a lumped-parameter model with four degrees of freedom, and the bit–rock contact is represented by a nonlinear function of a bit

Specific satellites with ultralong wings play a crucial role in many fields. However, external disturbance and self-rotation could result in undesired vibrations of the flexible wings, which affect the normal operation of the satellites. In severe cases, the satellites would be damaged. Therefore, it is imperative to conduct vibration suppression for these flexible structures. Utilizing fuzzy-proportional

In this article, the investigation of the use of a rolling particle damper under sinusoidal excitation is described. A rolling particle damper is a type of ball vibration absorber and consists of a rotating cylinder placed on a curved track mounted on a primary system. The rotating cylinder is partially filled with granular materials. When the rotating cylinder rolls inside the curved track, the granular

In this article, an adaptive nonsingular terminal sliding mode control scheme based on fractional order is proposed for a cable-driven manipulator with external disturbances, where the concentration is uncertain and the upper limit is known or unknown. Furthermore, a new adaptive fractional-order nonsingular fast terminal sliding mode algorithm with time-delay estimation is developed. The delay estimation

In this study, the transfer matrix method for multibody systems is used to study the vibration characteristics of a tracked vehicle system. The transfer matrix method has the advantages of not needing the global dynamics equations of the system, low order of system matrices, and fast dynamics computation speed. According to the solution process of vibration characteristics, a detailed dynamics model

In this article, a rotary valve is developed to obtain accurate high-frequency sinusoidal vibration waveforms. Then, a uniaxial electro-hydraulic shaking table controlled by a set of parallel rotary valves is constructed, which can superpose the sinusoidal vibration waveforms. The non-sinusoidal vibration waveforms including triangular vibration waveform, rectangular vibration waveform, sawtooth vibration

Over the past few years, deep learning–based techniques have been extensively and successfully adopted in the field of fault diagnosis. As the diagnosis tasks become more complicated, the structure of the traditional convolutional neural network (CNN) has to become deeper to deal with them, while the gradient of fault features may vanish within the deep network. In addition, all the features are treated

In this work, the damping characteristics of an actively constrained viscoelastic material layer are examined because of the inclusion of dispersed graphite particles within the viscoelastic material layer. The study is carried out by analysing the active–passive damping in a layered plate made of a substrate layer, a constrained viscoelastic particulate composite layer and a thin constraining piezoelectric

Motion-induced oscillations of the flexible single link and its payload at the tip have negative impact on the anticipated performance of the flexible manipulators and thus should be suppressed to achieve tip positioning accuracy and high-speed operation. Because of the structural flexibility, the dynamics of the flexible manipulator can be described by coupled Duffing oscillators when considering

Gear driving devices are commonly used in mechanical transmission systems. Due to the inevitable random errors in manufacturing, installation, and operation, the dynamics of a gear transmission system will fluctuate randomly. To reveal the dynamic characteristics, an interval parameters dynamic model of a single-stage spur gear pair is established, in which the uncertainties of displacement excitation

This article develops a coupling dynamic method focusing on the coupling relationship between the leg and the body of a legged robot. The dynamic equation of the method reflects the mechanism between an active operating part and a passive moving part among a multibody system. It is used to adjust the position and posture of the body by driving the motion of the joint of the leg, thereby solving problems

In this article, a magnetic suspension technique was introduced into the field of vibration absorption. Using the advantage of adjustable control parameters of a magnetic suspension system, a type of a magnetic suspension dynamic vibration absorber that can achieve broadband vibration suppression was designed. First, the theoretical model of a magnetic suspension dynamic vibration absorber was established

An active vibration control system to monitor and suppress the human forearm tremor is proposed in this article. The forearm is modelled as a uniform flexible continuous beam supported by a pin joint and a rotational spring at one end, whereas the other end is free. The beam is covered with a layer of piezoelectric sensor on its top surface and a layer of piezoelectric actuator on its bottom surface

In this article, a novel adaptive intelligent control scheme is proposed to stabilize a chaotic nonlinear system with unknown dynamics in the presence of uncertainties and external disturbances. The proposed control scheme is a combination of terminal sliding mode, adaptive, and neural controllers. Terminal sliding mode control provides appropriate finite-time stability and robustness against uncertainties

In this study, an extended state observer–based backstepping fast terminal sliding mode control is developed for the ride comfort of a full-car active suspension system. In the referred extended state observer–based backstepping fast terminal sliding mode control, the extended state observer is designed to estimate the lumped disturbances of external road excitation and uncertain dynamics. Then, a

The attempts to identify damping changes in a cracked beam can improve the accuracy of the nonlinear crack identification method. For the purpose of this aim, a parametric nonlinear equation of motion is obtained using the Euler–Bernoulli beam theory and parametric nonlinear breathing crack assumptions. Several experiments were conducted to identify the effect of breathing cracks on changing the damping

A beat traveling wave principle which combines beat vibration with a traveling wave is proposed. Based on the traveling wave principle and the beat vibration theory, a mathematical model is established to analyze the operation law of the beat traveling wave. Theoretical analyses and numerical simulations are used to study the amplitude variation of the beat traveling wave. Then, a spatial–temporal

One of the major challenges in the real-time control of structures is the uncertainty in identifying the mechanical properties of the system, including mass, stiffness, and damping. However, the presence of uncertainty in time-varying systems (under severe environmental factors, the dynamic characteristics of the system change due to damage) is more noticeable. In this article, to deal with the problem

In allusion to the issue of rolling bearing degradation feature extraction and degradation condition clustering, a logistic chaotic map is introduced to analyze the advantages of C0 complexity and a technique based on a multidimensional degradation feature and Gath–Geva fuzzy clustering algorithmic is proposed. The multidimensional degradation feature includes C0 complexity, root mean square, and curved

This article presents the use of the analytic signal procedure for processing the large volume of structural vibration data recorded in forced vibration tests. The analytic signal facilitates the computationally laborious task of extracting the steady-state amplitude for each response measure of interest from the recorded accelerations throughout the building at each operated frequency of the forced

This article deals with stabilization and optimal control of an articulated flexible arm by a passive approach. This approach is based on the boundary control of the Euler–Bernoulli beam by means of wave-absorbing feedback. Due to the specific propagative properties of the beam, such controls involve long-memory, non-rational convolution operators. Diffusive realizations of these operators are introduced

To overcome the shortcomings of the Bouc–Wen model, such as too many parameters, complex identification process, and long time consuming, the sensitivity of parameters was analyzed. A Bouc–Wen optimum model with sensitive parameters to guarantee calculating accuracy was established. First, according to the results of the magnetorheological damper’s mechanical property test, the sensitivity of Bouc–Wen

The brake squeal of automobiles has become one of the most annoying issues for passengers. Hence, it is essential to suppress the noise from the design stage of the braking system. In this article, the method for reducing squeal noise is explored based on the finite element model of the brake system. Studies on this model show that the structural deficiency of the brake caliper may cause the instability

This study addresses the consensus problem of leader-following multiagent systems, whose dynamics are governed by time-delay linear parameter-varying models with norm-bounded uncertainties. At first, a delay-dependent sufficient condition concerned with the existence of a parameter-varying sliding surface is given in terms of linear matrix inequalities. Then, a robust consensus among the leader and

A continuation method for bifurcation tracking is presented based on the proposed optimization problem formulation which is designed to locate the bifurcation periodic solution. The bifurcation detection problem is formulated as a constrained optimization problem. The nonlinear constraints of the optimization problem are imposed on the shooting function and bifurcation conditions derived from the Floquet

In this article, a novel vibration-based damage detection approach is proposed based on selecting effective cepstral coefficients, consisting of three main stages: (1) signal processing and feature extraction, (2) damage detection by combining effective cepstral coefficients through feature selection methods, and (3) performance evaluation. First, two feature extraction techniques are used in damage

Based on the Euler–Bernoulli beam theory, the natural vibration behavior of functionally graded nonuniform multiple beams has been investigated. It is assumed that the beams are joined by elastic translational springs, and the properties of the beams vary along the axial direction. The Chebyshev spectral collocation method has been used to convert the governing differential equations of transverse

In the current investigation, the thermoelastic vibration of a viscoelastic microbeam resting on the Winkler foundation is studied using the fractional-order theory. To describe the damping of the viscoelastic material according to experimental results, the Kelvin–Voigt model is replaced by a new form with a fractional-order derivative. The generalized thermoelasticity model and Euler–Bernoulli beam

Automobile brake squeal noise, which is nonlinear, friction-induced vibration in the frequency range 1–16 kHz, still remains a major problem for the automotive industry. This article presents analytical and experimental investigations into the application of dither control for active suppression of automobile disc brake squeal. Dither is a concept of active control that introduces high-frequency actuation

Online selection of the appropriate model and identifying its parameters based on measured vibrational data are among the challenging issues in dynamic system identification. After a severe earthquake, quick monitoring and assessment of structural health status play a crucial role in effective critical risk management for the building owners and decision-makers. The Bayesian multiple modeling approach

In this study, size-dependent nonlinear forced vibration of viscoelastic/flexoelectric nanobeams has been investigated. By calculating enthalpy and kinetic energy and using Hamilton’s principle, the coupled governing equations of viscoelastic/flexoelectric nanobeams are derived along with dependent electrical and mechanical boundary conditions. Furthermore, to take the effects of the small scale into

A low-conservative composite nonlinear feedback controller is proposed for singular time-delay systems with time-varying delay. The proposed composite nonlinear feedback controller not only improves the transient responses of the closed-loop system but it also has less conservatism than other composite nonlinear feedback controllers. The gain of the linear part of the composite nonlinear feedback controller

In this study, an observer-based robust model predictive control scheme is proposed to control a class of switched nonlinear systems in the presence of time delay and parametric uncertainties under arbitrary switching. Constructing an appropriate Lyapunov–Krasovskii functional in conjunction with an infinite horizon cost function, sufficient conditions are obtained to guarantee the asymptotic stability

The lightweight design of the gear system is the current tendency. The gearbox housing is modeled as a rigid body and is neglected in the gear dynamic analysis. It is of great significance to introduce the gearbox housing flexibility into the dynamic analysis and analyze the influence of the gearbox housing flexibility on the dynamic behaviors of the gear transmission system, as this can provide important

In this article, the observer-based robust preview tracking control problem is revisited for discrete-time Lipschitz nonlinear systems. The proposed observer-based preview control scheme is composed of the integral control action, the observer-based state feedback control action, and the preview feedforward action of the reference signal. Sufficient design condition of controller and observer gains

To study the wheel–rail contact and creep characteristics and the evolution law of corrugation with different wavelengths, the wave-like wear is idealized as continuous harmonic excitations consisting of three wavelengths and wave depths, and the vehicle–track space coupled dynamic model is established for specific analysis. The results show that when the wavelength is fixed and the wave depth increases

A comprehensive review of technologies and approaches for active safety systems designed to reduce ground vehicle crashes, as well as the associated severity of injuries and fatalities, is provided. Active safety systems are commonly referred to as systems that can forewarn a driver of a potential safety hazard, or automatically intervene to reduce the likelihood of an accident without requiring driver

Resonant piezoelectric shunts are a well-established way to reduce vibrations of mechanical systems suffering from resonant condition. The vibration energy is transferred to the electrical domain through the bonded piezoelectric material where it is dissipated in the shunt. Typically, electrical and mechanical resonance frequencies are several orders apart. As such, finding a suitable high inductance