Rubber Mounts Research Articles

Methods for Evaluating the Characteristics of the Stress-Strain State of Seismic Blocks Under Operating Conditions

The concept of the vibration and seismic isolation of heavy mining machines, buildings, and structures with rubber seismic blocks is considered. The concept of the seismic isolation of structures is very topical. In Japan, New Zealand, France, Greece, England, USA, and in a number of other countries, it is successfully used for the earthquake protection of such important structures as nuclear power stations, schools, bridges, museums, office and residential buildings. Seismic isolation systems including rubber blocks are most commonly used. The known publications in these countries do not present analytical calculations and technological peculiarities of manufacturing elements. In Ukraine, this concept was extended by developing seismic isolation blocks for the earthquake protection of residential buildings and vibration isolation blocks for the vibration protection of heavy equipment (weight of up to 300 t, used in Russia, Ukraine) and residential buildings. Results of static and dynamic tests of a parametric series of rubber seismic blocks for the vibration protection of residential buildings are presented. A pile design with anti-vibration rubber mounts is considered. Developed and tested rubber seismic block designs were used to protect against subway and motor vehicle induced vibrations two dwelling houses in Kiev (a ten-section ten-storey and a three-section 27-storey dwelling house) and three houses in Lvov. Vibration and seismic isolation with rubber seismic blocks provides a natural vibration frequency of building in the horizontal plane of under 1 Hz, which complies with the requirements of the state building codes and Eurocode 8 for the design of seismic isolation systems for buildings.

Structural Modelling of Automotive Engine Mounting from Kenaf Fibre Reinforced Natural Rubber/Thermoplastic Polyurethane “Green” Composites

This paper presents an investigation of deformation analysis using ANSYS of automotive engine rubber mount made from kenaf fiber reinforced natural rubber (NR)/thermoplastic polyurethane (TPU) composites. The modelling of mounting was conducted using CATIA software. To determine the of the Poisson’s ratio of this new material composites is important, which was required data to be filled into the ANSYS software. The Poisson’s ratio was calculated based on the previous data experiment from the stress-strain results. The analysis was focussing on the deformation and stress analysis effected from the pressure that was applied in the modelling and in the ANSYS simulation software which is 250 psi. The deformation and stress simulation results were then identified and discussed and the results were compared to the Natural Rubber material of the same design simulation.

Experimental verification for lateral-torsional coupled vibration of the propulsion shaft system in a ship

Recently, the propulsion shaft of a particular ship was fractured owing to high torsional vibration. To reduce this high torsional vibration, a coupling with low stiffness was applied. While applying this low stiffness coupling, an abnormal high torsional vibration occurred at the maximum speed of rotation of the shaft. When the speed of rotation of the shaft approached its maximum value, it operated in a stable condition and no high torsional vibration occurred initially. However, seconds later, high torsional vibration occurred suddenly. Because a rubber mount and flexible coupling were installed on the main engine, the root cause of this high torsional vibration could be attributed to the lateral-torsional coupled vibration of the shaft system. The lateral-torsional coupled vibration was investigated numerically after approximating the shaft system to a three-degrees-of-freedom Jeffcott rotor. To verify that the high torsional vibration is caused by the lateral-torsional coupled vibration, a test unit that can simulate this lateral-torsional coupled vibration occurring in the propulsion shaft is developed. Performing a vibration test with the test unit, it can be experimentally verified that the high torsional vibration occurring in the propulsion shaft of the particular ship was caused by the lateral-torsional coupled vibration. In addition, an estimation method for the speed range in which the lateral-torsional coupled vibration occurs is suggested.

Visualization analysis of the working process and dynamic characteristics comparison of a hydraulically damped rubber mount with resonant column channel

Combined with the finite element analysis (FEA) technology of fluid–structure interaction and nonlinear large deformation material, the integral FE models of a type of hydraulically damped rubber mount (HDM) with resonant column channel are set up. Based on the visualized simulation results, the working process of the HDMs is analysed, and the dynamic stiffness and the loss angles are compared. The calculation results show that the variation of the dynamic stiffness and the loss angle in the low-frequency domain is related to the flux and its hysteresis in the column channel. The effects of the decoupling membranes and the disturbing plate on the low-frequency dynamic characteristics are investigated by calculations. Results show that the setting of the decoupling membranes and their stiffness greatly change the dynamic stiffness and the loss angle of the HDM in the frequency domain below 50 Hz. And the disturbing plate and the variation of its diameter also affect the dynamic characteristics in the same frequency range. The accuracy of the FEA calculation is verified by the experiment.

Visualization of pyroshock wave reduction by insulator using a laser shock based simulation method

Various pyro-devices are used in space structures because of their high power-to-weight ratio, high reliability, and compact size. However, when a pyro-device fires, it generates a strong, high-frequency shock wave called a pyroshock wave, which causes high-frequency-sensitive electronic equipment to malfunction. Therefore, it is important to analyze and minimize pyroshock waves near electronic equipment to prevent damage. In this paper, we propose a shock wave scanning method by a Q-switched laser to analyze shock reduction and visualize shock wave propagation in a real-world complex structure. This technique was applied to evaluate and visualize the shock reduction by rubber insulators mounted in a configuration such that a pyroshock wave is transferred and propagated via a butyl rubber mount to an electronic component mounting panel. An average of 20% in the mean acceleration differences in shock response spectra between an actual pyroshock wave and a laser-simulated pyroshock wave was achieved. The use of the butyl rubber mount reduced the shock wave by 75%, and the reduced pyroshock propagation was quantitatively visualized.

Experimental Approach to Active Mounts Using Electromagnetic Actuator and Rubber with Consideration of Shock Resistance for Naval Shipboard Equipment

There is demand for stringent vibration isolation within machine installations in order to achieve maximum performance or to satisfy otherwise extreme criteria, particularly, when there is a strong source of vibration such as a motor pump. It is frequently necessary to prevent the transmission of these vibrations to other parts of the system for passenger comfort in vehicles, ships, trains, etc., or for the protection of delicate electronic equipment. In the defense sector, the need for equipment which is better at avoiding detection has led researchers to focus more on improving vibration isolation. In this paper, an active mount combined with a passive rubber mount and an electromagnetic actuator is proposed and examined for use in naval shipboard equipment. The electromagnetic actuator is suggested for improving performance and overcoming its inherent limitations which are caused by the friction between the magnet and coil. The design specifications of an active mount, such as required force, displacement, and frequency characteristics, are identified for the self‐excited pump system, and then an electromagnetic actuator active mount is redesigned with considering the shape of the passive rubber mount and shock resistance. The performance was examined on the single active mount using an external exciter, which could be simplified as two‐degree‐of‐freedom system, and also confirmed experimentally on an active mount system with four mounts using a motor system. From the results of applying the proposed electromagnetic active mount, a vibration reduction of about 20 dB for the motor equipment was observed for the excited frequency components of 1,600 rpm and its two harmonic components.

Dynamic characteristics of passive and semi-active cabin mounts for vibration control of a wheel loader

In this study, the dynamic characteristics of passive mounts and a semi-active magneto-rheological (MR) mount for vibration attenuation of a wheel loader cabin are experimentally evaluated. First, the design procedures of two different passive mounts are described, and the principal design parameters such as stiffness are determined from a simple but practically feasible dynamic model. Then, passive mounts with different material characteristics are manufactured and experimentally tested. Secondly, a semi-active MR mount is designed based on the field-dependent yield stress of MR fluid. A prototype of the MR mount is then manufactured considering two flow paths: annular path and radial path. Subsequently, the dynamic characteristics of the three mounts such as the frequency-dependent stiffness and damping are evaluated, and their salient properties are discussed. In addition, it is shown from the transmissibility investigation that the semi-active MR mount can effectively isolate unwanted vibrations in a wider operating frequency range compared with the passive rubber mounts.

Dynamic characteristics of passive and semi-active cabin mounts for vibration control of a wheel loader

In this study, the dynamic characteristics of passive mounts and a semi-active magneto-rheological (MR) mount for vibration attenuation of a wheel loader cabin are experimentally evaluated. First, the design procedures of two different passive mounts are described, and the principal design parameters such as stiffness are determined from a simple but practically feasible dynamic model. Then, passive mounts with different material characteristics are manufactured and experimentally tested. Secondly, a semi-active MR mount is designed based on the field-dependent yield stress of MR fluid. A prototype of the MR mount is then manufactured considering two flow paths: annular path and radial path. Subsequently, the dynamic characteristics of the three mounts such as the frequency-dependent stiffness and damping are evaluated, and their salient properties are discussed. In addition, it is shown from the transmissibility investigation that the semi-active MR mount can effectively isolate unwanted vibrations in a wider operating frequency range compared with the passive rubber mounts.

Enhancing the ride comfort of the off-road vibratory roller cab by adding damper hydraulic mount

In order to improve the vibratory roller’s ride comfort, a 3-D nonlinear dynamic model of the vehicle interacting with the off-road terrain is established. A damper hydraulic mount is studied and combined with the cab’s rubber mounts to simulate and evaluate the performance of the ride comfort. The weighted RMS acceleration responses of the vertical driver’s seat, the cab’s pitch and roll angle are chosen as objective functions. The results show that the cab’s rubber mounts combined with the damper hydraulic mount are clearly improved the ride comfort under various operating conditions. Especially, with damping coefficients cc3,4= 1.8 kN.s.m-1, the weighted RMS values of the vertical driver’s seat, the cab’s pitch and roll angle are greatly reduced by 27.8 %, 22.7 % and 64.3 % in condition of the vehicle traveling, and by 23.8 %, 20.0 % and 63.7 % in condition of the vehicle compacting on an elastic-plastic terrain.

Vibration Characteristics of Al6061-SiC Metal Matrix Composite based Rubber Mount for I.C Engine Chassis

Vibrations are found to be dangerous and reduce the life and reliability of the vehicle. The studies were carried out by many researchers to stiff the structures by increasing the wall thickness of the plates, rubber and to minimize the vibration by increasing the damping coefficient of the rubber materials. The conventional materials indicate an improvement in stiffness, but not satisfying the requirements of the engine vibration at different speed and load standards and also increased the mass of the structure. This research on the engine mount vibration isolation aims at developing an alternative material for the structures which exhibit good damping and stiffness characteristics. In terms of properties such as chemical resistance, ease of production, high strength to weight ratio and damping, composite materials are increasingly used in many engineering application where the vibration is predominant. In this paper, the steel plates are replaced by Al6061-SiC Metal Matrix Composites (MMC) and studies are carried out on the engine mount made of Al6061 MMC structural material and integrated with rubber. The static and dynamic properties of the Al6061MMC-rubber mounts are determined using experimental investigations. The harmonic analysis is also carried out to test the damping characteristics of the mounts.

Conceptual design of automobile engine rubber mounting composite using TRIZ-Morphological chart-analytic network process technique

Abstract An engine rubber mounting is one of the important parts of a vehicle. It is a function to isolate or absorb and to reduce vibration to the vehicle body thus to the passenger itself. Due to the engine compartments environment such as heat and massive vibration due to road conditions, the engine rubber mountings lifespan has been reduced. Thus several studies have been conducted to upgrade the material lifespan to make it more reliable and better engine mounting components. This paper presents the conceptual design of kenaf fiber polymer as automotive engine rubber mounting composites using the integration of Theory of Inventive Problem Solving (TRIZ). In this early stage, the solution is generated using 40 inventive principles and TRIZ contradiction method. The solution parameter for the specific design character is the selected using the morphological chart to develop a systematic conceptual design for the component. Four (4) innovative design concepts were produced and Analytic Network Process (ANP) methods were utilized to perform the multi-criteria decision-making process of selecting the best concept design for the polymer composite engine rubber mounting component.

Optimization Design and Performance Analysis of Vehicle Powertrain Mounting System

The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, the rubber mount exhibits better vibration isolation performance than the rigid connection. This paper presents a complete design process of the mounting system, including the vibration decoupling, vibration simulation analysis, topology optimization, and experimental verification. Based on the 6-degrees-of-freedom vibration coupling model of the powertrain mounting system, an optimization algorithm is used to extract the best design parameters of each mount, thus rendering the mounting system fully decoupled and the natural frequency well configured, and the optimal parameters are used to design the mounting system. Subsequently, vibration simulation analysis is applied to the mounting system, considering both transmission and road excitations. According to the results of finite element analysis, the topological structure of the metal frame of the front mount is optimized to improve the strength and dynamic characteristics of the mounting system. Finally, the vibration bench test is used to verify the availability of the optimization design with the analysis of acceleration response and vibration transmissibility of the mounting system. The results show that the vibration isolation performance of the mounting system can be improved effectively using the vibration optimal decoupling method, and the structural modification of the metal frame can well promote the dynamic characteristics of the mounting system.

Reduction of vibration forces transmitted from a radiator cooling fan to a vehicle body

This article presents methods for reducing transmitted vibration forces caused by mass unbalance of the radiator cooling fan during vehicle idling. To identify the effects of mass unbalance upon the vibration characteristics, vibration signals of the fan blades were experimentally measured both with and without an added mass. For analyzing the vibration forces transmitted to the vehicle body, a dynamic simulation model was established that reflected the vibration characteristics of the actual system. This process included a method described herein for calculating the equivalent stiffness and the equivalent damping of the shroud stators and rubber mountings. The dynamic simulation model was verified by comparing its results with experimental results of the radiator cooling fan. The dynamic simulation model was used to analyze the transmitted vibration forces at the rubber mountings. Also, a measure was established to evaluate the effects of varying the design parameters upon the transmitted vibration forces. We present design guidelines based on these analyses to reduce the transmitted vibration forces of the radiator cooling fan.

Experimental Identification On Non Linear Properties of Rubber Mount

In actual installation, rubber mount are usually excited by different engine force amplitude and frequency. For better characterization of rubber mount, dynamic properties of metal to rubber mount are tested in this paper by using hysteresis loop method. Stiffness and loss factor of rubber mount are calculated from measured hysteresis loop. Experimental works are carried to identify the non-linearity in the amplitude dependent and frequency dependent properties of rubber mount. the s-shaped of hysteresis loop represent as non-linear behavior of rubber mount. the comparison is done for the dynamic properties of rubber mount under different excitation condition. the non-linear behavior of the rubber mount under excitation forced are reported. the result show stiffness change non-linearly according to different amplitude excitation force under different excitation frequency. the observation is significant especially when the excitations force is higher than 5N for the small metal to the rubber mounts. However this observation is different compared to the condition where excitation frequency getting higher. the non-linearity in the rubber mount is becoming not significant when the excitation frequency is getting higher.

Optimization of the Vibrational Comfort of Passenger Vehicles through Improvement of Suspension and Engine Rubber Mounting Setups

The aim of this work is to develop a measurement methodology to perform a vibration analysis of a vehicle. It proposes new setups in the suspension systems, including springs, shock absorbers, and rubber mountings of the engine system, to improve the passengers’ comfort levels. The influence of each of these modifications in the vibration levels at specific points is analyzed. The importance of human interaction analysis is clear as, in the past, it was frequently left aside. This is because only the vehicle dynamic behavior is generally emphasized in the vehicles designed. Therefore, this work stresses that concerns about human vibration levels result in vehicles with good performance also in comfort levels, focusing on the users’ well‐being. A combination of different sets of rubber mountings, springs, and shock absorbers are tested. The changes proposed in this paper are analyzed in sequence and, based on the results, the best combination is proposed.

Vibration Response Prediction on Rubber Mounts with a Hybrid Approach

Vibration Response Prediction on Rubber Mounts with a Hybrid Approach

Vibration Analysis and Modeling of an Off‐Road Vibratory Roller Equipped with Three Different Cab’s Isolation Mounts

This study proposes a dynamic model of the vibratory roller interacting with the off‐road deformed terrain to analyze the low‐frequency performance of three different cab’s isolation mounts under the different operating conditions. In order to evaluate the ride comfort of the vibratory roller with the different cab’s isolation mounts, a three‐dimensional nonlinear dynamic model is established. The power spectral density (PSD) and the weighted root mean square (RMS) of acceleration responses of the vertical driver’s seat, cab’s pitch, and roll vibrations are chosen as objective functions in the low‐frequency range. Contrastive analysis of low‐frequency vibration characteristics of the vibratory roller with the traditional rubber mounts, the hydraulic mounts, and the pneumatic mounts is carried out. Experimental investigations are also used to verify the accuracy of models. The research results show that the hydraulic mounts have an obvious effect on mitigating the cab vibration and improving the ride comfort in comparison with the traditional rubber mounts and the pneumatic mounts.

Design and Evaluation of a Semi-Active Magneto-rheological Mount for a Wheel Loader Cabin

In this study, a semi-active magneto-rheological (MR) mount is designed and manufactured to minimize unwanted vibrations for the cabin of heavy vehicles. Normally, working conditions in heavy vehicles are extremely rugged. Usually, the heavy vehicles use passive rubber mounts for the reduction of vibrations from road. However, the passive mount has definite performance limitations because the passive mount has a fixed resonance frequency when the design is finished. An MR application is one of the solutions because the viscosity of MR fluid can be controlled. As a first step, an experimental apparatus was established for performance evaluation of the mounts. The apparatus has hydraulic excitatory, force, and displacement sensors. Performance of two different passive mounts used in industrial fields were evaluated. The passive mount data of force-displacement, force-velocity, and displacement transmissibility were collected and tested. After that, an MR mount was designed and manufactured that provides better performance using the passive mount data. The MR mount uses two different flow paths, annular duct and radial channels, for generating the required damping force. The field-dependent damping forces were then evaluated with respect to the moving stroke and input current. In this work, in order to control the damping force, an on-off controller associated with the fast Fourier transform (FFT) was used. The control results of the MR mount were compared with the results of passive rubber mounts. It was shown that the semi-active MR mount can attenuate vibrations more effectively at all frequency ranges compared with the passive rubber mount.

Optimization of passive control performance for different hard disk drives subjected to shock excitation

Laptop personal computers (LPCs) and their components are vulnerable devices in harsh mechanical environments. One of the most sensitive components of LPCs is hard disk drive (HDD) which needs to be protected against damages attributable to shock and vibration in order to have better magnetic read/write performance. In the present work, a LPC and its HDD are modeled as two degrees of freedom system and the nonlinear optimization method is employed to perform a passive control through minimizing peak of HDD absolute acceleration caused by a base shock excitation. The presented shock excitation is considered as half-sine pulse of acceleration. In addition, eleven inequality constraints are defined based on geometrical limitations and allowable intervals of lumped modal parameters. The target of the optimization is to reach optimum modal parameters of rubber mounts and rubber feet as design variables and subsequently propose new characteristics of rubber mounts and rubber feet to be manufactured for the HDD protection against shock excitation. The genetic algorithm and the modified constrained steepest descent algorithm are employed in order to solve the nonlinear optimization problem for three widely-used commercial cases of HDD. Finally, the results of both optimization methods are compared to make sure about their accuracy.

Vibration Analysis of a Generator Anti-Vibration Rubber Mounts

Vibration Analysis of a Generator Anti-Vibration Rubber Mounts