Lifetime of metal rubber isolator with different vibration amplitudes

The lifetime of metal rubber isolator and its characteristics during lifetime experiment were studied. The stepped-up test principle was adopted to study the lifetime of resonant frequency, the breakage form of metal rubber isolator was obtained, and the relation between the energy dissipation, resonant frequency and stiffness was obtained in (available) lifetime of the isolator. Furthermore, the reason for the changes of properties of metal rubber isolator was analyzed with contact model of metal rubber material. The results show that if the resonant amplitude is large, the stiffness of metal rubber isolator will be kept steadily for a long time, its resonant frequency will be stable and the effective working time in the protecting area will be long. The lifetime of metal rubber isolator is more than 1376 h in the experiment. The main failure forms of metal rubber isolator are accumulative wear and breaking of metal wires and spirals. In protecting area the metal rubber isolator can work effectively for a long time, and the effective working time depends on the concrete working condition.

Material Model Research on Rubber Vibration Isolators

A viscohyperelastic constitutive model is proposed to describe the mechanical behaviour of vibration isolation rubber under broad-band vibration. This constitutive model comprises two parts： a component with three parameters to characterize the hyperelastic static properties of rubber materials, and the other component incorporating two relaxation time parameters, corresponding to high and low strain rates, respectively, to describe the dynamic response under vibration and impact loadings. Based on this proposed constitutive model, a series of experiments were performed on two types of rubber materials over a wide strain rate range. The results predicted from this model are in good agreement with the experimental data.

Effects of Fatigue Characteristics on Static and Dynamic Performance of Eucommia Rubber Isolators

This study aimed to investigate the effect of fatigue characteristics on the static and dynamic performance of Eucommia ulmoides gum isolators, and to explore the performance changes of Eucommia ulmoides gum isolators with different formulations. For this purpose, we used five formulations of Eucommia ulmoides gum isolators and set different fatigue test methods to study the static and dynamic performance changes of Eucommia ulmoides gum isolators with different formulations by changing the amplitude. The experimental results showed that the addition of Eucommia ulmoides gum had an impact on the performance of the isolator, and the number of fatigue cycles would lead to the hardening of the Eucommia ulmoides gum isolator and changes in its static and dynamic performance. In the range of two million vibrations, the performance change of the isolator was significant in the early stage and then tended to be flat, indicating that the impact of fatigue on the performance of the isolator would not continue to persist. It is worth noting that the study found that the addition of 30% Eucommia ulmoides gum had the least impact on the performance of the isolator under fatigue. Therefore, for long-term use of Eucommia ulmoides gum isolators, attention should be paid to their fatigue characteristics to ensure their stability and reliability. Additionally, this study provides a reference for the design and application of Eucommia ulmoides gum isolators. In summary, this study provides important reference value for a deeper understanding of the fatigue characteristics of Eucommia ulmoides gum isolators and for ensuring their stable and reliable performance. .

The Dynamic Characteristics of Silicone Rubber Isolator

The dynamic stiffness and the specific damping energy, as well as the vibration response characteristics of a silicone rubber isolator were researched. The results of the vibration test showed that the silicone rubber isolator was excellent in the performance of vibration control. The dynamic stiffness and the damping characteristics were non-linear. From the comparison between experimental results and simulation analysis, the displacement transmissibility characteristics of the isolator were obtained. As a result, the dynamic characteristics of the isolator could be accurately described by the quadratic type non-linear terms at small amolitude.

Research on the Pressure Regulator Effect on a Pneumatic Vibration Isolation System

The pneumatic vibration isolator(PVI)plays an increasingly important role in precision manufacturing.In this paper,aiming to detect the performance of the pressure regulator in the PVI system,a PVI testing system with a pressure regulator is designed and developed.Firstly,the structure of the pneumatic spring is presented and analyzed,and the nonlinear stiffness is obtained based on the ideal gas model and material mechanics.Then,according to the working principle and continuity equations of ideal airflow,a dynamic model of the PVI system with a pressure regulator is established.Through the simulation analysis,the vibration isolation performance is improved with the efficient and precise pressure regulator.The average values of both the vibration velocity and transmission rate decrease when the vibration is set to 4,10,20 and 40 Hz,respectively.The experiments demonstrate the reliability and effectiveness of the pressure regulator.This achievement will become an important basis for future research concerning precision manufacturing.

金属橡胶复合隔振器的动静态性能

设计一种对称式金属橡胶与线弹簧复合的隔振器,基于整体隔振,考虑安装板的柔性因素,建立相应的等效线性动力学模型.通过准静态力学试验,分析线弹簧刚度、金属橡胶密度和加载位移对金属橡胶复合隔振器准静态性能的影响.同时,进行随机振动试验,研究金属橡胶复合隔振器在整体隔振中的隔振性能.试验结果表明,复合样件的刚度特性趋向于线性效果.金属橡胶复合隔振器在谐振点处的峰值衰减是线弹簧隔振器的5倍以上,且系统的随机振动响应在频段0.12~2.00 kHz内都有较大程度的衰减.

二级柔性减振系统设计及力学性能分析

为解决二级减振引起个别仪器振动的局部放大、使得力学环境不能满足运行要求的问题,首先,针对金属橡胶双层减振系统,充分考虑安装板的柔性刚度,建立了刚柔复合的二级减振系统模型;其次,基于目标频率对二级减振的频率响应函数进行系统的刚度解耦,实现了减振器刚度的求解,并应用有限元进行随机振动分析,验证了刚柔复合二级减振系统理论模型的可行性;最后,利用振动台进行了试验验证。结果表明,当二级减振系统满足工程刚度需求,其一阶固有频率低于40 Hz时,减振效率可达到70%以上,试验与仿真结果基本一致。

一种小动静比橡胶隔振器仿真与试验

通过隔振器内部结构设计,在保证承载能力的同时降低橡胶隔振器的动态刚度。开展橡胶隔振器的静态变形、在给定静变形下的动态仿真分析,表明该隔振器在静态力-位移曲线上具有负斜率特性,对应隔振器内部结构的失稳变形;进行隔振器的静压试验、动态试验和隔振系统中的振动传递试验,结果表明,静态力-位移曲线试验结果呈现负斜率特性,在静态曲线上不同工作点处的固有频率呈现负斜率处最小的特性。

基于刚度矩阵分析法的变刚度橡胶支座力学性能研究

在橡胶支座力学行为基础上提出了一种适合隔离三维地震或竖向振动的新型变刚度橡胶支座,并阐述了能解决变刚度支座非均质体力学问题的刚度矩阵分析法。首先,基于常用橡胶支座解析解和压剪试验的非线性响应分析,采用刚度矩阵分析法对该支座进行计算,其结果和试验值高度一致验证了该方法计算精度较高。接着,对比三种支座结果:在相同外部荷载和材料参数下,厚层支座力和变形最大,变刚度支座和普通支座力和变形显著低于厚层支座;不同轴压下,P-Δ效应表现为厚层支座力和变形及水平刚度受轴压影响最为显著,而变刚度支座与普通支座受轴压影响较小。通过算例表明,可通过调整变刚度支座实现竖向刚度的优化。综合而言,变刚度支座对力和变形的承载能力较好,为三维隔震(振)提供了一种简单实用的解决方案。

基于橡胶本构模型管路隔振器性能仿真研究

采用管路隔振器是降低船舶管路系统振动噪声传递的有效手段,但舰船管路比较复杂需要根据管路规格设计系列化隔振器。如何有效地预报不同规格管路隔振器在实际使用过程中的性能是管路隔振器系列化设计亟待解决的问题。为此本文通过橡胶拉伸试验拟合橡胶超弹性本构参数,利用有限元方法对多款隔振器性能(静变形和固有频率)进行仿真计算,并由试验对计算结果进行验证。结果表明,设计的隔振器数值仿真与试验结果误差率均低于10%,证明该参数能有效预报多规格隔振器性能。本文结果可为舰船管路隔振器系列化设计提供指导。

热环境下金属橡胶隔振结构的耗散特性及参数识别

由于金属橡胶的耗散特性对温度非常敏感且显著影响隔振性能,因此,开展热环境下金属橡胶隔振结构的耗散及参数识别研究十分重要.本文设计了一种双层金属橡胶隔振结构,研究了环境温度对该隔振结构耗散特性的影响规律,基于试验数据建立了金属橡胶双层隔振结构的非线性本构模型.首先,在不同温度下对该隔振结构进行了一系列耗散特性试验,绘制了隔振结构在各工况下的耗散特性曲线,计算了隔振结构的耗散系数、耗散能量以及最大变形势能,分析了温度、振幅、频率对金属橡胶双层隔振结构耗散特性的作用规律.然后,使用非线性最小二乘法对隔振结构的参数进行了识别,建立了该金属橡胶隔振结构的非线性泛函本构模型,准确预测了隔振结构在各工况下的耗散特性曲线.

基于热空气加速老化氯丁橡胶隔振器的寿命预测

对氯丁橡胶(CR)隔振器进行热空气加速老化试验,基于老化程度构建Dakin寿命预测模型,并进行相关计算分析和验证。结果表明,预测值可信,并基于老化程度变化的实验值和预测值对模型进行修正,根据修正后的模型测算出隔振器在25℃下的使用寿命为48.22年。

基于数值仿真的金属橡胶隔振器疲劳寿命研究

为了验证金属橡胶隔振器在轨道交通领域的适用性,提出了一种试验与仿真相结合的疲劳寿命预测方法。该方法首先构建车-轨-浮置板刚柔耦合动力学模型,获取了隔振器的疲劳载荷谱;其次开展准静态和疲劳加速试验,推导出了材料刚度随载荷加载次数的变化关系;最后搭建隔振器仿真模型,研究了疲劳载荷下隔振器寿命值。结果表明:金属橡胶隔振器的预测寿命值和试验测试的使用寿命均超过300万次,满足地铁浮置板道床隔振器的要求。

橡胶颗粒改良流态粉煤灰路基隔振性能研究

为解决铁路列车运行引发的路基与地基振害问题,基于阻尼耗能原理设计一种新型橡胶颗粒改良流态粉煤灰(FAR)路基。通过室内配合比试验,制备满足工程路用性能要求的FAR路基材料;采用瞬态激振方法测试FAR路基材料的阻尼比,分析橡胶颗粒掺量对FAR路基材料阻尼特性的影响规律,揭示FAR路基的阻尼耗能机理;采用COMSOL有限元软件建立轨道-路基-地基三维耦合数值模型,对比研究普通路基与橡胶颗粒掺量为5%、10%和15%的FAR路基动应力和振动加速度的传播规律,分析验证FAR路基的隔振性能。研究结果表明:橡胶颗粒的掺入降低了FAR路基材料的强度和干密度,掺量不超过固体混合料质量的15%时,路基基本物理力学性能可满足铁路工程应用要求。橡胶颗粒的黏弹特性使FAR路基内部动应力发生损耗或衰减,路基阻尼比随橡胶颗粒掺量增加而增大,且橡胶颗粒掺量相同时,橡胶颗粒粒径越小FAR路基的阻尼比越大,推荐采用150目橡胶颗粒。相比普通路基,FAR路基基床底层、路基土体和地基土体的动应力均有减小,衰减幅值为10%~30%,可有效避免路基动弹变形、地基振陷等灾害发生;FAR路基振动主频范围内地面振动加速度级减小2~6 dB,最高达到83 dB,验证了新型FAR路基的良好隔振性能。研究结果可为铁路FAR路基的隔振设计与铁路路基的安全运营提供参考。

金属橡胶阻尼三向减振器力学特性与环境效应

为满足精密装备多向循环载荷和多重环境减振降噪需求,设计了一款金属橡胶和斜置矩形弹簧组合式三向减振器,建立了动力学理论模型和动态试验测试系统,分析减振系统固有频率、动刚度和阻尼比在各工况下演变规律。通过理论模型预测与试验相结合方法,分析了激振量级对三向组合式减振器动态力学性能的影响规律,以及在常温、高低温、盐雾和湿热等环境下的动态性能指标变化规律和阻尼耗能机制。研究结果表明:随着激振量级的增加,三向组合式减振器固有频率、动刚度和阻尼比有减小趋势,出现刚度软化现象,动力学理论模型解析分析相关性能演变趋势与试验结果具有较好一致性;在各服役环境工况下,金属橡胶阻尼三向减振器力学性能最大变化率可看出该减振器力学特性具有较高稳定性和一致性。

中功率涡桨发动机减振系统设计与试验研究

针对涡桨飞机发动机振动严酷的问题,利用氢化丁腈橡胶设计了一种中功率涡桨发动机减振系统,基于Workbench ANSYS软件研究了含橡胶实体单元的减振系统动力学建模分析方法;再以加速度传递率为隔振性能评价准则,设计了中功率涡桨发动机减振性能试验系统,通过试验研究减振系统的减振性能。结果表明:在小变形假设下利用橡胶材料硬度估算其弹性模量,由线弹性模型模拟橡胶材料开展减振系统动力学仿真分析,仿真分析结果与扫频试验结果误差小于10%;通过随机振动试验测得减振系统对发动机1阶窄带激励的隔振效率大于70%,对2阶窄带激励的隔振效率大于85%,设计的减振系统对发动机窄带激励具有优良的隔振效果。

基于本构神经网络橡胶隔振器动态特性建模

提出一种基于本构和BP神经网络模型的橡胶隔振器动态特性的建模方法并验证模型的有效性。首先,分别建立本构模型、BP神经网络模型和基于本构和BP神经网络的联合模型,来表征橡胶隔振器的动态特性。第二,利用最小二乘法对本构模型进行参数识别;以实测的动刚度和滞后角为训练样本,对BP神经网络模型进行模型辨识。计算结果表明,基于本构和BP神经网络的联合模型能更好地表征橡胶隔振器动态特性的振幅相关性和频率相关性。最后,计算3种模型受到随机位移激励的时域响应,并进行试验验证。试验结果表明,基于本构和BP神经网络的联合模型能更加准确地描述橡胶隔振器的动态特性。

尼龙板-高阻尼厚层橡胶支座力学性能试验研究

隔振支座用于工业厂房楼层内的机械隔振,但传统的叠层橡胶支座存在重量大、造价高的缺点。采用尼龙板替代传统橡胶支座中的钢板,高阻尼厚层橡胶替代传统橡胶层,形成一种简易机械隔振支座,其具有质量轻、造价低的优点。进行了尼龙板材料性能试验和隔振支座的水平剪切、竖向压缩和极限压缩等力学性能试验,分析了压应力、剪应变、加载频率、橡胶剪切模量对支座力学性能的影响。结果表明:尼龙板-高阻尼厚层橡胶支座力学性能稳定,尼龙板可以替代传统叠层橡胶隔振支座中的钢板;支座的水平剪切性能具有较强的剪应变相关性和压应力相关性,而加载频率对其影响则较小;增大橡胶的剪切模量可以显著提升支座的水平剪切性能和竖向压缩性能,但也会进一步削弱水平剪切性能的剪应变相关性和压应力相关性。

装配式橡胶隔振器模型修正与静态特性研究

为探究装配式橡胶隔振器通用化、系列化、组合化设计的特点,促进同类型产品研发应用。采用有限元仿真与试验相结合的方法,开展某系列装配式橡胶隔振器静态特性研究。首先,采用静力分析的方法测算隔振环在装配过程中储存的能量,对装配式橡胶隔振器模型进行修正。然后,应用修正后的装配式橡胶隔振器模型进行静态特性分析。最后,将仿真结果与试验结果进行对比,验证方法的可行性。试验证明,3种型号装配式橡胶隔振器在额定载荷下的仿真和试验静变形误差分别为3.5%、18.4%、5.3%。与修正前相比,修正后仿真模型静刚度误差从35.4%降至15.1%。结果表明,隔振环的装配方向对装配式橡胶隔振器的形状与静态特性有较大的影响。同时,也验证研究方法具有较高的准确性和可行性,可为装配式橡胶隔振器技术应用提供理论指导。

基于隔振垫超弹性本构模型的橡胶浮置板轨道动力仿真

以地铁橡胶浮置板轨道为研究对象,基于隔振垫超弹性本构建立地铁车辆-橡胶浮置板轨道-隧道耦合动力分析模型,计算橡胶浮置板轨道的动力响应及减振效果。结果表明:隔振垫超弹性本构模型计算的轨道结构及隧道壁动力响应均更接近实测数据;不同隔振垫刚度工况下,超弹性本构模型计算得到的轨道结构位移均小于线弹性本构模型,钢轨和轨道板位移峰值分别相差10%和40%左右;超弹性本构模型计算得到的轨道板加速度峰值较小而基底加速度峰值较大,且随隔振垫刚度增加,2种模型计算的轨道板振动差异减小、基底振动差异显著增大,常用隔振垫静刚度范围(0.019~0.100 N·mm^(-3))内超弹性本构模型与线弹性本构模型计算的基底加速度峰值之比最大为2.46,而采用线弹性本构模型将低估橡胶浮置板轨道基底振动;超弹性本构模型计算得到的轨道板振动及基底高频振动较小,而基底低频振动较大,传递损失小,而采用线弹性本构模型将高估地铁振动特征频段(50~80 Hz)的减振作用,放大轨道固有频率附近(16~31.5 Hz)振动。