Vibration Suppression Method Research Articles

Research on subsurface damage mechanism and suppression method of ultrasonic vibration–assisted grinding of sapphire components under extreme service environment

Research on subsurface damage mechanism and suppression method of ultrasonic vibration–assisted grinding of sapphire components under extreme service environment

Bandgap adjustment of a sandwich-like acoustic metamaterial plate with a frequency-displacement feedback control method

Several types of acoustic metamaterials composed of resonant units have been developed to achieve low-frequency bandgaps. In most of these structures, bandgaps are determined by their geometric configurations and material properties. This paper presents a frequency-displacement feedback control method for vibration suppression in a sandwich-like acoustic metamaterial plate. The band structure is theoretically derived using the Hamilton principle and validated by comparing the theoretical calculation results with the finite element simulation results. In this method, the feedback voltage is related to the displacement of a resonator and the excitation frequency. By applying a feedback voltage on the piezoelectric fiber-reinforced composite (PFRC) layers attached to a cantilever-mass resonator, the natural frequency of the resonator can be adjusted. It ensures that the bandgap moves in a frequency-dependent manner to keep the excitation frequency within the bandgap. Based on this frequency-displacement feedback control strategy, the bandgap of the metamaterial plate can be effectively adjusted, and the vibration of the metamaterial plate can be significantly suppressed.

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.

Suppression of solar array vibration by torque compensation using a magnetorheological actuator: A hardware-in-the-loop test study

Sun-tracking-induced vibrations of a large flexible solar array are characterized by a wide frequency range and persistent disruptions, making them an important challenge for a high-precision spacecraft. This paper describes a hardware-in-the-loop test for a novel vibration suppression method that employs magnetorheological torque compensation. To provide the compensating torque, a test bench is built using a magnetorheological actuator (MRA). A comprehensive model is employed to quantitatively analyze suppressions in terms of solar array driving, solar array motion, and spacecraft disturbance. For comparison, the test is run in both open-loop and closed-loop modes. The results demonstrate that with closed-loop control, the maximum fluctuation of driving torque decreases by 50.90%. The sun tracking achieves a more stable speed. Moreover, disturbances produced by the vibration of the solar array are decreased by 59.84%. These findings suggest that using torque compensation with an MRA can successfully reduce the sun-tracking-induced vibration of a large flexible solar array while minimizing the impact on the spacecraft platform.

Blade redesign based on inverse design method for energy performance improvement and hydro-induced vibration suppression of a multi-stage centrifugal pump

As the urgency of the global energy crisis escalates and environmental protection standards become more stringent, the industrial sector is placing increased emphasis on enhancing energy efficiency and advancing vibration control technologies. Within this context, multi-stage centrifugal pumps (MSCPs), pivotal in energy systems, play a crucial role in influencing both system performance and environmental impact. This paper embarked on employing an inverse design method (IDM) to innovate the redesign of MSCP blades, introducing a steady-state index for characterizing the intensity of unsteady pressure fluctuations, thereby streamlining optimization costs. Optimization techniques utilizing an artificial neural network model and a multi-objective evolutionary algorithm were employed to achieve an optimal balance between maximizing energy efficiency and reducing hydro-induced vibrations. The optimized MSCP enhanced not only boosting performance but also a 2.75 % increase in weighted efficiency, significantly widening the high-efficiency operation zone. The improvement in vibration characteristics was manifested by an average reduction of more than 25 % in the amplitude of the primary frequency of pressure pulsations within the double volute, with a maximum reduction reaching 50.9 %. Furthermore, the research delved into the analysis of the internal energy dissipation mechanisms of MSCPs, drawing upon the entropy production theory and the enstrophy concept. This analysis reveals that energy dissipation in the mainstream zones is predominantly affected by shear enstrophy, whereas, in the wall regions, it is primarily governed by fluid velocity. The comprehensive performance enhancement of the optimized model is significantly credited to the refinement of the blade profile.

Investigation into fatigue failure of cable brackets and vibration suppression methods

The cable bracket is one of the most important components of high-speed EMUs, as it supports the cables of sensors. The fatigue failure of the bracket can severely affect the operation of the vehicle. In this study, the dynamic response of the cable bracket, including dynamic stress and acceleration, is obtained through field tests. The results show that the modal vibration of the bracket excited by high-frequency excitation in the wheel–rail system is an important cause of fatigue failure of the bracket. Rail welded joints in the track and polygonal wear of the wheelset further exacerbate the vibration and of the bracket. A model of the virtual vibration table is proposed to simulate the actual excitation experienced by the bracket. The effects of the cantilever beam length, steel plate thickness, and pre-tightening torque of the bolts on the dynamic stress of the bracket are studied using the virtual vibration table. Several vibration suppression methods are proposed. The results indicate that the dynamic stress of the bracket caused by the rail welded joints can be effectively reduced through the adjustment of the pre-tightening torque of the bolts or the appropriate reduction of the cantilever beam length. The findings of this study can serve as a reference for suppressing vibration and preventing fatigue failure of the bracket.

A Terminal Residual Vibration Suppression Method of a Robot Based on Joint Trajectory Optimization

Vibration problems have become one of the most important factors affecting robot performance. To this end, a terminal residual vibration suppression method based on joint trajectory optimization is proposed to improve the accuracy and stability of robot motion. Firstly, based on the characteristics of the friction nonlinearity due to joint coupling and physical feasibility of dynamic parameters, a semidefinite programming method is used to identify dynamic parameters with actual physical meaning, thereby obtaining an accurate dynamic model. Then, based on the result of the residual vibration time domain analysis, a joint trajectory optimization model with the goal of minimizing joint tracking error is established. The Chebyshev collocation method is used to discretize the optimization model. The dynamic model is used as the optimization constraint, and barycentric interpolation is used to obtain the optimized joint motion trajectory. Finally, industrial robot experiments prove that the vibration suppression method proposed in this article can reduce the maximum acceleration amplitude of residual vibration by 62% and the vibration duration by 71%. Compared with the input shaping method, the method proposed in this paper can reduce the terminal residual vibration more effectively and ensure the consistency of running time and trajectory.

Random Vibration Characteristics and Vibration Suppression of an Aero-engine Inlet Rake Fabricated by Laser Powder Bed Fusion

The inlet rake is generally installed in aero-engine during rig and flight test for flow field pressure and temperature measuring. There are usually complex flow channels and pipelines inside the rake to extract air flow to the sensor. The laser powder bed fusion(L-PBF) technique was applied in rake fabrication recently due to its progressive layer stacking molding procedure. However, the difference of thermoforming method between L-PBF and the traditional casting process leads to the mechanical property disparities of the material. In this work, the determinants of random vibration response of the inlet rake manufactured by L-PBF with GH4169 powder were studied individually. The stiffness and yield property of the material were investigated by the specimen tensile test, which indicates higher elasticity modulus and yield stress comparing to the ones by castling or forging process. The damping ratio of the inlet rake was obtained through stress attenuation characteristics experiment and analysis under stepwise excitation. The stress distribution and resonance margin of the inlet rake under the aero-engine random vibration spectrum were simulated by finite element modal and random vibration analysis. The results showed that the damping ratio of the L-PBF inlet rake is much smaller than engineering recommendations, and the resonance margin is insufficient. Thus, the stress level of the inlet rake was very high, especially in the blade root section, quite close to the yield limit of the material. To solve this problem, the vibration suppression methods of the inlet rake were studied from the perspective of structural design optimization and damping ratio increasing. Through the rational design of the resonance margin and addition of vibration damping structure, the vibration stress of inlet rake was significantly suppressed. As the result, the rake was installed in the inlet during the aero-engine rig test for flow field pressure and temperature measurement successfully.

Research on Vibration Suppression Methods for Industrial Robot Time-Lag Filtering

This paper analyzes traditional vibration suppression methods in order to solve the vibration problem caused by the stiffness of flexible industrial robots. The principle of closed-loop control dynamic feedforward vibration suppression is described as the main method for solving robot vibration suppression. This paper proposes a method for time-lag filtering based on T-trajectory interpolation, which combines the T-planning curve and the time-lag filtering method. The method’s basic principle is to dynamically adjust the trajectory output through the algorithm, which effectively suppresses the amplitude of the harmonic components of a specific frequency band to improve the vibration response of industrial robot systems. This experiment compared traditional vibration suppression methods with the time-lag filtering method based on T-trajectory interpolation. A straight-line method was proposed to measure the degree of vibration. The results demonstrate that the time-lag filtering method based on T-trajectory interpolation is highly effective in reducing the vibration of industrial robots. This makes it an excellent option for scenarios that demand real-time response and high-precision control, ultimately enhancing the efficiency and stability of robots in performing their tasks.

A new cutting tool filled with metallic lattice and design method for vibration suppression in milling

Enhancing the vibration suppression performance of cutting tools is crucial for achieving high-performance cutting of difficult-to-machine materials. This paper presents a novel cutting tool as well as its design method for vibration suppression in milling process. By incorporating a high-damping lattice structure into the cutting tool, the dynamic stiffness of the spindle-holder-tool system can be effectively increased based on the dynamic absorber effect. To achieve this goal, the natural frequency of the cutting tool filled with metallic lattice is tuned with the spindle-holder subassembly by altering the geometric parameters of the metallic lattice. A comprehensive dynamic model of the spindle-holder-tool system, considering the complex tool geometries, is developed to accurately analyze this system’s behavior and a design procedure is proposed to optimize the cutting tool. The geometric parameters of the lattice structure in the cutting tool are optimized based on the dynamic model, while the cell type of the high-damping lattice is selected by experiments. The proposed cutting tool is additively manufactured using the selective laser melting technique, and a comparison is made with a conventional indexable cutting tool with a solid tool body. Both simulations and impact hammer tests demonstrate an increase of 18.3% in the dynamic stiffness of the proposed cutting tool filled with metallic lattice compared with the conventional indexable cutting tool. Furthermore, a large number of milling tests are carried out on titanium alloy Ti-6Al-4V to validate the vibration suppression performance of the cutting tool filled with metallic lattice. Experimental results show that the stability limit corresponding to the proposed cutting tool can be doubled compared with the conventional indexable cutting tool.

Harmonic-Oriented Design and Vibration Characteristic Suppression for Interior Permanent Magnet Motors

In this article, a radial-electromagnetic-force-harmonic-oriented design methodology is proposed to suppress motor vibration. In the proposed methodology, the radial electromagnetic force harmonics innovatively act as the effective bridge between structural field and vibration performance. And avoiding low-order and large-amplitude radial electromagnetic force harmonics is the premise of designing low-vibration PM motors. For extensive investigation, a 36-slot/8-pole IPM motor with different winding configurations and variable rotor parameters is chosen as a design example. Then, vibration suppression methods of lowest-nonzero-spatial-order-shifting in the stator system and dominant-harmonic-amplitude-reduction in the rotor system are proposed. Next, the performances of the IPM motor are simulated for validating the proposed methodology. Finally, a prototype motor is fabricated and experimented. Both theoretical derivation and test results are presented to verify the validity of the motor and the proposed design methodology.

Vibration suppression method for dual-flexible manipulator considering bearing friction based on nonlinear disturbance observer

Vibration suppression method for dual-flexible manipulator considering bearing friction based on nonlinear disturbance observer

Fixed-Time Control for a Flexible Smart Structure With Actuator Failure: A Broad Learning System Approach.

This article proposes an adaptive fault-tolerant control (AFTC) approach based on a fixed-time sliding mode for suppressing vibrations of an uncertain, stand-alone tall building-like structure (STABLS). The method incorporates adaptive improved radial basis function neural networks (RBFNNs) within the broad learning system (BLS) to estimate model uncertainty and uses an adaptive fixed-time sliding mode approach to mitigate the impact of actuator effectiveness failures. The key contribution of this article is its demonstration of theoretically and practically guaranteed fixed-time performance of the flexible structure against uncertainty and actuator effectiveness failures. Additionally, the method estimates the lower bound of actuator health when it is unknown. Simulation and experimental results confirm the efficacy of the proposed vibration suppression method.

A time-varying boundary method for multimodal vibration suppression of beam

A time-varying boundary method for multimodal vibration suppression of beam

Improvement and application of electromagnetic vibration and noise suppression method for electric vehicle motor

Motor induced Electromagnetic Vibration and Noise (EVN) are mainly affected by Radial Electromagnetic Force Wave (REFW) and related harmonic amplitude. Therefore, in the past discussion on the suppression of motor induced EVN, it usually starts from this aspect. For this reason, this study proposes a method to suppress EVN. Firstly, the influence of the quantity of rotor slots on the function of Induction Motor (IM) is analyzed; Then, the optimization strategy of rotor slot fit is proposed according to the results; Finally, an optimization strategy for the skewness of IM is proposed. Based on the above contents, the experiment realized the suppression of EVN induced by electric vehicle motor. The experimental results show that the parameters of the motor are optimal when the quantity of rotor slots is 53. It is better to weaken the harmonic amplitude related to the low-order REFW. The peak values of the motor using the research strategy at the second and third vibration modes are - 35 db Hz and - 38 db Hz respectively, which are lower than those of the traditional motor. To sum up, the strategies proposed in the study can remarkably suppress the EVN of IM and improve the function of electric vehicles, which will promote the electric vehicle industry ‘s development.

Vibration Analysis and Suppression Methods of the Wing of an Underwater Glider

Vibration analysis and suppression methods are widely studied in mechanical systems. In this study, rubber damping materials were employed to enhance the vibration suppression performance of the wing of an underwater glider. A finite element model was established to analyze the vibration characteristics of the wing. The excitation characteristics of the actuator were determined by experimental methods. The wet mode shapes and corresponding frequencies of the wing of the underwater glider were investigated. The vibration suppression performance of rubber damping materials with different thickness and hardness was discussed. The optimal parameters of the rubber pads on various positions were provided to minimize the excitations from the actuator. This paper provides valuable insights for developing vibration suppression techniques for the wings of an underwater glider.

Magnetostrictive-based induced current inversion and amplification: Semi-active vibration suppression for multiple-degree-of-freedom flexible structures

Vibration suppression technology is indispensable in the operation of multiple-degree-of-freedom (MDOF) structures. Properties such as a light weight and reliability are essential for an MDOF structure. However, truss structures tend to be flexible and susceptible to vibration from external influences. Hence, vibration suppression for MDOF flexible structures is necessary. This paper proposes a new semi-active vibration suppression method with a magnetostrictive transducer that can be applied to vibration suppression of an MDOF flexible structure. The proposed method is achieved through an electrical control circuit consisting a magnetostrictive transducer, an inversion capacitor, an electronic switch, and diodes. The control input of the proposed method is considered the induced current. With strategic selection of the circuit statuses, the amplitude of the induced current can be inversed and amplified. Our proposed control strategy is to control the circuit statuses so that the vibration suppression performance can be as effective as possible. The control strategy is determined based on the vibration displacement and velocity of the structure. Numerical simulations were performed to predict the vibration suppression performance. Subsequently, validation experiments were performed using a vibrating cantilevered truss structure, which was considered an MDOF structure composed of many aluminum bar members and iron joints. Under various experimental conditions, the proposed method achieved suppression rates of 12.1–26.7%. The results validated that the proposed method is more effective than a conventional passive method for the vibration suppression of an MDOF flexible structure. The proposed method may aid in ensuring the safe operation of MDOF flexible structures, such as trusses, under extreme conditions.

Research on vibration suppression of satellite bearing cylinder based on particle damping

During the launch and separation phases, the satellite will be subjected to massive random loads and impact loads, which will quickly cause broad frequency vibrations in the thin-walled skin structure of the satellite bearing cylinder, leading to resonance in severe cases and causing fatigue and damage to the equipment and structure. A vibration suppression method of satellite-bearing cylinder based on PD (particle damping) technology is proposed to overcome the problem of abnormal vibration of satellite-bearing cylinder structure at resonance frequency excitation. Firstly, the DEM-FEM coupling model of the force-bearing cylinder and particle damper is established using the DEM-FEM coupling (discrete element method and finite element method coupling) theory. Secondly, the acceleration value response of the bearing cylinder's upper-end surface is used to evaluate the vibration-dampening effect. The particle dampers' particle diameter, particle material, particle filling ratio, and installation site parameters are then optimized for design. Finally, the ground vibration damping test of the satellite bearing cylinder was designed. According to the experimental results, after installing the best damping scheme, the vibration attenuation of the satellite bearing cylinder may achieve 32%. The peak acceleration at the first and second-order intrinsic frequencies is lowered by 78.46% and 94.3%, respectively. This result also verifies the correctness of the theoretical model and simulation model.

Dynamic modeling and RBF neural network compensation control for space flexible manipulator with an underactuated hand

In space operation, flexible manipulators and gripper mechanisms have been widely used because of light weight and flexibility. However, the vibration caused by slender structures in manipulators and the parameter perturbation caused by the uncertainty derived from grasping mass variation cannot be ignored. The existence of vibration and parameter perturbation makes the rotation control of flexible manipulators difficult, which seriously affects the operation accuracy of manipulators. What’s more, the complex dynamic coupling brings great challenges to the dynamics modeling and vibration analysis. To solve this problem, this paper takes the space flexible manipulator with an underactuated hand (SFMUH) as the research object. The dynamics model considering flexibility, multiple nonlinear elements and disturbance torque is established by the assumed modal method (AMM) and Hamilton's principle. A dynamic modeling simplification method is proposed by analyzing the nonlinear terms. What's more, a sliding mode control (SMC) method combined with the radial basis function (RBF) neural network compensation is proposed. Besides, the control law is designed using a saturation function in the control method to weaken the chatter phenomenon. With the help of neural networks to identify the uncertainty composition in the SFMUH, the tracking accuracy is improved. The results of ground control experiments verify the advantages of the control method for vibration suppression of the SFMUH.

Research on vibration suppression of rigid flexible coupling manipulators based on genetic algorithm optimization

Aiming at the problem that the rigid flexible coupling manipulator generates elastic vibration during movement, which reduces the positioning accuracy and work efficiency, we propose a method of end vibration suppression based on cosine function superposition and multi population genetic algorithm. First, we get the relationship between the elastic vibration of the flexible arm and the joint trajectory motion according to the dynamic model of the system. Then, the cosine function superposition is used as the basis function to construct motion parameters of joints and the minimum residual vibration amplitude at the end of the flexible arm is used as the objective function. The undetermined coefficients in the basis function are optimized by multi population genetic algorithm to obtain the optimal trajectory. Finally, the simulation and experiment results show that the residual vibration amplitude is reduced by 60.6%. The proposed method can suppress the residual vibration at the end of the flexible arm and improve the work efficiency.