Hydraulic Damper Research Articles

Design of Integrated Dual Spiral Spring and Rotary Hydraulic Damper System for Torsional Vibration Damping in Pesticide Sprayer Gearbox

Design of Integrated Dual Spiral Spring and Rotary Hydraulic Damper System for Torsional Vibration Damping in Pesticide Sprayer Gearbox

Анализ применения гидравлических гасителей колебаний в конструкциях рессорного подвешивания подвижного состава железнодорожного транспорта

Purpose: consideration of the issue of the use of hydraulic vibration dampers in spring suspension of various types of railway rolling stock. The article provides an overview of the layout of hydraulic vibration dampers in the spring suspension of rolling stock, their advantages and disadvantages are given Methods: review and analysis of spring suspension designs of various types of traction and non-traction rolling stock in operation, as well as patented designs. Analysis of the arrangement schemes of hydraulic vibration dampers in the spring suspension of rolling stock. Results: the main reason for the use of hydraulic dampers in spring suspension is the inability of cylindrical springs to minimize the influence of oscillatory movements of rolling stock that occur during its movement. The necessity of using hydraulic vibration dampers in structures of various types of rolling stock is substantiated. The arrangement schemes of hydraulic vibration dampers are considered. Examples of the use of hydraulic dampers in spring suspension of various types of rolling stock are given. Practical significance: the necessity of using hydraulic vibration dampers is shown not only in the structures of the undercarriage of passenger cars and locomotives, but also in the spring suspension of freight cars. The use of hydraulic vibration dampers makes it possible to minimize the negative impact of oscillatory movements on both the structure of the rolling stock and the health of passengers and locomotive crews, as well as to increase the comfort of their stay. The use of hydraulic dampers in the spring suspension of freight rolling stock can increase the speed of its movement by improving the running qualities of freight cars and the degree of safety of transported goods.

Research on Vibration Reduction Characteristics of High-Speed Elevator with Rolling Guide Shoes Based on Hydraulic Damping Actuator

Research on Vibration Reduction Characteristics of High-Speed Elevator with Rolling Guide Shoes Based on Hydraulic Damping Actuator

Research on Bifurcated Origami Hydraulic Dampers for Real Road Vibration Loads

Cylindrical hydraulic dampers are commonly utilized to mitigate vibrations in machinery and structural applications. These devices generally feature a single linear stroke and are often linked to rotary joints to handle complex loading conditions. However, their installation in confined spaces, such as vehicle suspensions, poses considerable difficulties. In this research, we introduce an innovative bifurcated origami hydraulic damper with nonlinear damping capabilities. Initially, we formulated the collapsible conditional equations essential for the design of the bifurcated origami hydraulic dampers. We then examined the fluid dynamics within the damper and its flow channels, determining that the damping force is proportional to the square of the velocity. Furthermore, we developed motion equations based on the derived damping force and suggested vibration analysis methods using the Runge–Kutta approach. For the mass-spring vibration system, we created an experimental setup with the bifurcated origami hydraulic damper and performed vibration tests using noise signals recorded from a vehicle traveling on a gravel road, thus validating its damping performance and efficacy. Additional tests, which varied the orifice size at the end of the origami structure, as well as the type and temperature of the internal fluid, showed that the orifice size had a more pronounced effect on damping efficiency than the fluid type and temperature. This confirmed the vibration-damping effectiveness of the bifurcated origami hydraulic damper.

Modelling and Experimental Study of a Passive Frequency-Dependent Vehicle Suspension Damper

Abstract The recent trends in the automotive industry have enforced chassis solutions beyond the reach of conventional systems. Thus, extending the functionality of passive hydraulic dampers is vital in improving their effectiveness while maintaining low production and operating costs. This paper presents a general structure of a passive shock absorber with so-called frequency-dependent (FD) damping characteristics and points to constitutive elements of the valves used in this type of an adaptive damper. A mathematical description of FD damper is provided together with a model developed in the Siemens AMESim environment. The performance of the model was verified against the data from tests with a real, commercially available FD shock absorber. Furthermore, in order to emphasise its efficiency, the authors have carried out a study involving quarter car models (QCM) with and without the FD damper, respectively. The results have clearly shown major advantages of utilising FD dampers in a suspension.

Development of a Prototype Hydraulic Damping Device for Hot Water Heating Circuit in Pulse Mode

This paper provides a comprehensive exploration into the design and implementation of the hydraulic damping device within a pulse mode hot water heating loop. It outlines a systematic approach aimed at optimizing system performance, detailing the operational principles of the pulse mode heating circuit and presenting a structured construction scheme for the hydraulic damping apparatus. Accompanying this analysis is a simplified diagram illustrating the hydraulic damping system, offering a clear visual representation of its integration within the heating circuit. Through mathematical transformations, essential parameters such as complex impedance, frequency function, and vibration frequency characteristics are derived, providing valuable insights into the dynamic behavior of the system. Culminating this investigation, the paper constructs the frequency response of the circuit, offering a comprehensive understanding of its dynamic behavior across varying frequencies. This synthesis of theoretical frameworks and practical applications advances our understanding of pulse mode hot water heating technology, paving the way for enhanced efficiency and performance in heating systems.

Investigations on interpretable nuclear-grade hydraulic damper monitoring and diagnosis from multi-source high-dimensional profile data

Condition monitoring and fault diagnosis is important to ensure smooth machine operation, in which the use of multi-source high-dimensional profile data composed of multiple physical signals collected by multiple sensors for machine health monitoring and fault diagnosis has not been fully explored. In this paper, interpretable monitoring and diagnostic methods are proposed to analyze multi-source high-dimensional profile data and identify equipment operational status. Firstly, polynomials of segmenting profiles as well as a Lasso model are established to obtain sparse features. Then, for offline data with historical fault labels, an optimal linear hyperplane classifier is constructed to interpretably study the impact of different features on a decision. For online data with only normal samples, constructing an optimal hypersphere enables the measurement of operational status. Large-scale nuclear-grade hydraulic damper profile data are used to demonstrate how the proposed interpretable models work and show their physical interpretation for monitoring and fault diagnosis.

Ways to Protect Equipment from Hydraulic Shock

The hydraulic equipment is experiencing damage to its components and even the mechanical equipment owing to hydraulic shock induced by a sudden rise in load, resulting in a step reaction in the hydraulic system. An analysis of the hydraulic system is conducted to protect the equipment from the detrimental effects of hydraulic shock. This analysis includes examining components such as the hydraulic damper, centrifugal pump, accumulator, control valve, and others. The primary function of the power component is to mitigate hydraulic stress by altering the pump’s flow rate. The control element initiates the reversing of the valve in the hydraulic system in order to mitigate hydraulic shock. The auxiliary components primarily concentrate on enhancing the efficiency of the accumulator and maximizing the synergistic utilization of damping components. By adjusting the input value, one may regulate the flow rate and pressure of the system. The discussion revolves around finding the most efficient frequency in the shortest amount of time.

Cavitation Modeling and the Hysteretic Behavior Investigation on Twin-Tube Hydraulic Adjustable Damper

Cavitation Modeling and the Hysteretic Behavior Investigation on Twin-Tube Hydraulic Adjustable Damper

Design and experiment of electromagnetic-hydraulic-rubber integrated vibration isolator

Low-frequency radiated noise, characterized by a distinctive “acoustic fingerprint” is generated when vibrations from marine machinery propagate through a ship’s hull into the ocean. This type of noise travels long distances with concentrated and stable energy, posing a significant threat to a ship’s acoustic stealth capabilities. Active-passive hybrid isolation is the primary method for reducing low-frequency radiated noise from ships; however, technical challenges remain, such as effectively integrating active and passive components, achieving high output force in a compact design, and addressing the poor linearity of actuator output at low frequencies. To address these issues, this paper presented an innovative electromagnetic-hydraulic-rubber integrated vibration isolator. Firstly, the study analyzed the dynamic characteristics of a two-degree-of-freedom isolation system and investigated the influence of active-passive hybrid vibration isolator parameters on control force and vibration reduction performance. Secondly, it was established that the magnetic circuit model and magnetic field strength expressions for the electromagnetic actuator using magnetic circuit analysis derive the analytical relationship between electromagnetic force, current amplitude, and frequency using the energy method. Subsequently, a mathematical model was developed for the rubber-hydraulic suspension component to examine its dynamic characteristics, hydraulic damping, and hydraulic force amplification transmission laws. Lastly, we organically combine the electromagnetic actuator with the rubber-hydraulic suspension and conduct a multi-physics joint simulation of the integrated vibration isolator using Comsol software to verify the effectiveness of the optimized design and vibration isolation control. Experimental research was carried out on the dynamic characteristics, output force properties, and fatigue characteristics of the integrated vibration isolator prototype. Results indicated that the established models and methods can achieve over 90% accuracy in predicting the performance of the electromagnetic actuator’s output force and exhibit good linearity within the 5–400 Hz range. The rubber-hydraulic suspension can achieve an amplification factor of up to 1.5 for the electromagnetic force while reducing the transmission of vibrations to the base. The research findings can enhance the low-frequency vibration isolation performance of marine machinery equipment and improve their acoustic stealth capabilities.

Cavitation induced hydraulic yaw damper failure and its effect on railway vehicle dynamic stability

Hydraulic yaw damper (HYD) is an important suspension component that ensures the safe and stable operation of high-speed railway vehicles. However, HYD experiences the performance degradation and failure during service. Recent research found that the cavitation in HYD can affect vehicle stability by deteriorating the dynamics performance of HYD. To reveal the influence mechanism and quantify the effect extent of cavitation on hunting stability, this study delves into the cavitation phenomenon in HYD through theoretical modeling, numerical simulation and experimental validation. Considering the gas phase composition in hydraulic oil and the dynamic process of each phase transformation, a multi-phase interaction dynamic model of the hydraulic oil was originally proposed. Based on this sub-model, the physical parametric model of the HYD was established and integrated into the vehicle system as an advanced force element to study the effect of cavitation on vehicle hunting stability. The results indicate that cavitation can lead to insufficient damping force in the extension or compression stroke of HYD, subsequently affecting the vehicle hunting stability. Comparing the effects of different initial gas content on bifurcation characteristics and hunting frequency, it is observed that an increase in initial gas content results in a decrease in both linear and nonlinear critical speeds, changes in the bifurcation type and an increase in the hunting frequency. Furthermore, this effect is nonlinear, exhibiting sensitive ranges and saturation values. To ensure operational stability of high-speed vehicles, measures should be taken to prevent cavitation in HYD.

Amplitude-Sensitive Single-Pumper Hydraulic Engine Mount Design without a Decoupler

Engine mounts serve three primary purposes: (1) to support the weight of the engine, (2) to lessen the transmitted engine disturbance forces to the vehicle structure/chassis or airplane fuselage, and (3) to limit the engine motion brought on by shock excitations. The engine mount’s stiffness must be high to control large engine motions and low to control chassis or vehicle body vibration. When hydraulic engine mounts are used, a device called a decoupler creates the dual stiffness requirement. However, numerous investigations have shown that the decoupler has the potential to rotate within its cage bound and become stuck or sink and obstruct fluid flow between the fluid chambers due to a density mismatch between the decoupler and the working fluid. In addition, most hydraulic engine mounts with a decoupler no longer act as vibration isolators but as hydraulic dampers. This study suggests a new amplitude-sensitive hydraulic engine mount design without a decoupler, where the vibration isolation of the engine mount is retained and there is a 75% reduction in the peak frequency, which further enhances the engine mount’s capabilities in comparison to the current hydraulic engine mounts with a decoupler. The new design concept and its mathematical model and simulation results will be presented.

Coupled occupant-suspension-seat system analysis and vehicle-specific design optimization

A suspension seat is generally designed to achieve attenuation of low frequency whole-body vibration for a broad range of vehicles. Owing to the strong dependence of its vibration isolation performance on the nature of vibration excitation, an optimal performance could be realized via optimal tuning of suspension for specific classes of vehicles. In this study, a coupled occupant suspension seat model is developed and analyzed to identify optimal design parameters for different classes of vehicles. The multibody dynamic model of the air suspension seat is formulated considering kineto-dynamics of the suspension system and the elastic motion-limiters. The component models, namely, air spring with auxiliary air volume, hydraulic damper, and cushion, are identified from the laboratory-measured static and dynamic characteristics. A two-degree-of-freedom occupant model, is integrated to the suspension seat model to account for contribution due to occupant biodynamics. Model validity is examined using the laboratory-measured responses with a rigid load and a human occupant of similar body weight, and analyzed for different body weights and excitation spectra. The results suggest strong dependency of the suspension resonance frequency on nonlinear behavior of the air spring and the seated body mass. The model is subsequently employed to identify optimal coordinates of the air spring to achieve nearly constant natural frequency for a broad range of body masses. Furthermore, the model is used to identify optimal linkage and suspension design parameters with an objective to minimize the SEAT (Seat Effective Amplitude Transmissibility) for different spectral classes of earth moving machines defined in the ISO-7096 standard, while limiting the suspension travel. It is shown that the optimal coordinates of air spring could yield nearly constant natural frequency for different body weights, while damper could help limit the suspension travel, in addition to notable reductions in SEAT, ranging from 9% to 31% for different spectral classes of vehicles.

Velocity and load dependent dynamic shock absorber friction at stationary conditions

When it comes to vehicle vertical dynamics, the characteristics of shock absorbers are of high importance. With the increasing use of active suspension systems, it becomes possible to adapt the hydraulic damping force to the road event, while the friction force is not controllable. As a result, friction becomes more relevant and can negatively affect passenger ride comfort. In many mechanical applications, it is observed that friction in lubricated sliding conditions is velocity and load dependent. In contrast, shock absorber friction, and therefore suspension friction, is commonly considered as quasi-static, i.e. characterised by a constant potential. Since the shock absorber is predominantly in motion over a wide velocity range, it is necessary to improve the understanding of friction characteristics especially in the dynamic domain. In this study, modified valve-free shock absorbers are presented that allow the observation of dynamic friction properties experimentally. As not covered by previous studies, the effect of side force (load) as a main parameter to increase friction is investigated. It is observed that its effect varies significantly with velocity and alters the stationary friction-velocity curve, also known as the Stribeck curve. In addition, the shape of the Stribeck curve depends strongly on the shock absorber's oil volume. These novel results emphasise a substantial, interdependent influence of load and velocity on the (elasto-)hydrodynamic properties of the dynamic shock absorber friction force, which was not identified in the literature. The dynamic friction force exceeds the quasi-static friction force multiple times, and also exceeds the hydraulic damping force for considerable side forces in the lower velocity range up to 60 mm/s. Consequently, the total shock absorber force under presence of side force is determined. The findings can be used to improve active suspension control or to improve vehicle simulation by enabling the parametrisation of dynamic shock absorber friction models.

Modelling and cycle‐by‐cycle control of an electromechanical engine valve actuator with impact speed limiter based on hydraulic damper

AbstractVariable valve actuation (VVA) systems based on electromechanical valve actuators (EMVAs) enable a flexible operation and management of internal combustion engines that results in a reduction of pollutant emission and fuel consumption while improving engine power and efficiency. However, to achieve the benefits promised by EMVAs, it is of utmost importance to guarantee the catch of the valve by the system magnets with an acceptable impact speed of the valve at the end‐strokes. Valve catching failures can severely damage engine valves while high impact speeds induce mechanical wear and unacceptable noise. The soft landing control of the valve at the end‐strokes is challenging because of system nonlinearities, parameter uncertainties, and external disturbances. The complexity of the control design increases further when industrial cost‐effective solutions are sought. This paper presents a novel solution for reducing the impact speed of the valve without the use of costly position valve sensors. The proposed solution leverages on a small hydraulic damper (HD) embedded into the EMVA and a feedback cycle‐by‐cycle controller. The passive element reduces the impact speed while the controller adjusts at every engine cycle the EMVA coil currents based on pressure peaks detected in the HD to guarantee valve catching while steering the impact speed toward its minimum. The design of the controller exploits a physics‐based model that maps the pressure peak in the HD onto the impact speed and a gradient descent algorithm is adopted searching the minimum. The closed‐loop permanence is assessed in simulation by using an experimentally validated EMVA model and considering detailed dynamics of the HD. Numerical results show the ability of the proposed control architecture to reduce the impact speed and its robustness to parameters variations (oil temperature) and external disturbances (gas pressure forces).

A novel cable-net buffer device for recovering reusable launch vehicle: Design, dynamic modeling, and performance analysis

At present, reusable launch vehicle technology (RLV) has become a research hotspot in the aerospace field and one of the major development trends in this industry. With reference to the aircraft carrier’s arresting cable technology, this paper puts forward a novel cable-net buffer device for recovering the first stage of launch vehicle. The device can transfer load through a cable-pulley mechanism, and then complete the first stage recovery by losing the kinetic energy and gravitational potential energy of the first stage through hydraulic dampers and preloaded counterweights. In order to analyze the performance of this cable-net buffer device, the finite element software ABAQUS is adopted to establish a rigid-flexible coupling dynamic model. In this model, the cable-pulley mechanism is simulated by connector and shell elements, the damping force of the hydraulic dampers by VUAMP subroutine, and the preloaded counterweights by mass point. And then, performance evaluation indexes of this buffer device are proposed in this paper. Meanwhile, the dynamic simulation, using the established dynamic model, is carried out under different device design parameters and working condition parameters. On the one hand, the simulation results show that the tower span and damping force have remarkable effects on the buffer performance. On the other hand, among all working condition parameters, only the fall point deviation has a significant effect on the buffer performance, but this effect is less than that of the design parameters. Finally, combing the dynamic model and the surrogate model technique, this paper obtains feasible boundaries of design parameters of the device for the subsequent detailed design of it. Researches in this paper will provide new ideas for the development of RLV.

A forward-inverse dynamic model for the hydraulic damping(magnetorheological) actuator based on cyclic stress–strain

Magnetorheological dampers (MRDs) are applied to hydraulic systems, which not only improve the underdamped characteristics of valve-controlled cylinder systems, but also help hydraulic actuators to resist high load impact. However, the high power density leads to the complexity of the internal flow channel of the damper, which seriously affects the output accuracy of the damping force. It can lead to the fact that existing dynamics models cannot accurately describe the hysteresis characteristics of the MRD. Therefore, this study proposes a simple and general dynamic model of MRD, which solves the problem that existing models are complex and difficult to invert. Firstly, the hydraulic damping actuator with the series MRD is taken as the research object. Based on the stress–strain hysteresis characteristics under the cyclic constitutive model, the hyperbolic tangent curve is reorganized and normalized. It can accurately describe the yield formation and yield dissipation stages of the hysteresis loop. Secondly, the relationship between the parameters of the dynamic model and the current is obtained according to the mechanical experimental data. Then the inverse model of the MRD is established by using the method of section-backstepping. Finally, in the static experiment, the mean absolute percentage error (MAPE) of the force at different velocity is less than 7.5%; in the dynamic experimental test, the MAPE of the force is 9.7%. The inverse dynamics model is verified to have high tracking performance under both static and dynamic forces. And it also indirectly confirms the effectiveness of the forward model.

Functional assessment of longitudinal road evenness by the weighted longitudinal profile (WLP)

Longitudinal evenness is one of the most important quality criteria of roads. Vehicles can be regarded as dynamic systems consisting of masses, springs, hydraulic dampers, anti-roll bar etc. They are governed by mechanical laws, i.e. when passing the road, the systems respond to the unevenness with vertical excitation. The impacts are multifaceted. In addition to effects on road safety, driving comfort and pavement loading, the dynamic forces enhance the vehicle’s resistance to movement and consequently the vehicle’s energy demand. This in turn leads to a higher energy consumption and subsequently to an increase in CO2 emissions in road traffic. Against this background, the quality criteria for longitudinal evenness need to be defined by the mechanical impact on drivers and road construction in order to meet the concerns of road users and public authorities. For the assessment of longitudinal evenness, several indicators are in practice. In many countries, the IRI (International Roughness Index) is used for assessment purposes as well as for acceptance of construction works. However, the IRI depends on the velocity and, strictly speaking, on the mechanical system it represents. In order to overcome these shortcomings, the WLP (Weighted Longitudinal Profile) has been developed. Irregular, periodic and transient manifestations of unevenness can be individually addressed, safely detected and precisely located. It takes into account the entire range of speeds and dynamic properties relevant to road traffic. The paper covers the explanation of the indicator, the relationship to vertical dynamics, the deduction of limiting values and the application to road evenness data. The results are visualized and compared to the conventional approach.

The impact of vibration on buildings: Problems and solutions

The article presents a comprehensive overview of a study investigating the influence of soil-foundation interaction on the natural frequencies and vibration safety of reinforced concrete cellular and frame buildings. Through numerical modelling and analysis, the researchers investigate the relationship between structural modes and soil-induced vibrations, emphasizing the sensitivity of vibration frequencies to soil composition. Findings reveal that alterations in foundation conditions can significantly affect building dynamics, particularly in mid-rise structures, highlighting the importance of targeted monitoring for early detection of potential issues. Furthermore, the study discusses the implications of vibrations on human comfort and safety, underscoring the need for effective vibration mitigation strategies. Various damping systems, including hydraulic, dry friction, and dynamic dampers, are proposed as practical solutions to minimize the adverse effects of vibrations on both structures and occupants. Overall, the study underscores the critical role of vibration safety in ensuring the resilience and well-being of buildings and their inhabitants.

Assessment of the frame strength of a passenger trolley model KVZ-TsNII in the Femap software package

Currently, the safety of rolling stock traffic cannot be assessed only by the technical condition of the car and track. The impact of loads arising during operation and transmitted from the car to parts and components of the bogie can be simulated using the specialized software package Femap. Modern development technologies make it possible to determine the influence of loads to assess strength using elasticity theory methods. When considering this process, it is possible to identify stressedstrained areas under the influence of loads. This procedure makes it possible to prevent the development of cracks in the mechanical part of the car and to simulate the impact of loads on components and parts during their redistribution. During operation, the car experiences not only vertical load, but also lateral, transverse and longitudinal forces that act when the train moves. This article discusses a 3D model of the KVZ-TsNII passenger trolley frame. The load is transferred to vertical and horizontal sliders, a hydraulic vibration damper, a bolster, a central cradle suspension, longitudinal, transverse and side beams. The Femap software package allows to simulate stress-strain areas that arise with normalized indicators and with increasing loads or pressure upon a given part during operation.