橡胶减振装置在铁道运输系统中是必不可少的部件。基于将橡胶结构大变形和高阻尼特性考虑在内的自然频率域(NFR-Natural Frequency Region)方法,针对实际工业减振产品CUS单元在整个冲击过程中的动力响应测试,分别用2种模拟冲击质量体的...橡胶减振装置在铁道运输系统中是必不可少的部件。基于将橡胶结构大变形和高阻尼特性考虑在内的自然频率域(NFR-Natural Frequency Region)方法,针对实际工业减振产品CUS单元在整个冲击过程中的动力响应测试,分别用2种模拟冲击质量体的有限元模型(点质量模型和实体模型)进行较详尽的分析,评估实体橡胶减振系统的时域冲击响应,所模拟的结果和测试数据吻合良好。可为有关工作提供参考,有助于更准确地模拟橡胶减振系统的动力响应,从而加快和优化设计过程。展开更多
The compatibility of the IIR damping material was studied by use of DSC and DMA methods.The results is that the compatibility is very good between IIR and the resin vulcanizing reagent and there is only one mount in t...The compatibility of the IIR damping material was studied by use of DSC and DMA methods.The results is that the compatibility is very good between IIR and the resin vulcanizing reagent and there is only one mount in the charts of DSC or DMA.The studies of the results is very significant for the study on the damping characteristic of the damping materials.At the same time,we also discussed the reason through analysing the two molecular structures.展开更多
A dynamic model of a flexible rotor supported by ball bearings with rubber damping rings was proposed by combining the finite element and the mass-centralized method.In the proposed model,the rotor was built with the ...A dynamic model of a flexible rotor supported by ball bearings with rubber damping rings was proposed by combining the finite element and the mass-centralized method.In the proposed model,the rotor was built with the Timoshenko beam element,while the supports and bearing outer rings were modelled by the mass-centralized method.Meanwhile,the influences of the rotor’s gravity,unbalanced force and nonlinear bearing force were considered.The governing equations were solved by precise integration and the Runge-Kutta hybrid numerical algorithm.To verify the correctness of the modelling method,theoretical and experimental analysis is carried out by a rotor-bearing test platform,where the error rate between the theoretical and experimental studies is less than 10%.Besides that,the influence of the rubber damping ring on the dynamic properties of the rotor-bearing coupling system is also analyzed.The conclusions obtained are in agreement with the real-world deployment.On this basis,the bifurcation and chaos behaviors of the coupling system were carried out with rotational speed and rubber damping ring’s stiffness.The results reveal that as rotational speed increases,the system enters into chaos by routes of crisis,quasi-periodic and intermittent bifurcation.However,the paths of crisis,quasi-periodic bifurcation,and Hopf bifurcation to chaos were detected under the parameter of rubber damping ring’s stiffness.Additionally,the bearing gap affects the rotor system’s dynamic characteristics.Moreover,the excessive bearing gap will make the system’s periodic motion change into chaos,and the rubber damping ring’s stiffness has a substantial impact on the system motion.展开更多
通过在橡胶基体中集成多种功能性橡胶颗粒(FRGs),构筑具有多相网络结构的阻尼橡胶材料.首先通过扫描电子显微镜(scanning electron microscopy,SEM)和原子力显微镜(atomic force microscopy,AFM)观察所制备集成材料的微观形貌,然后探究...通过在橡胶基体中集成多种功能性橡胶颗粒(FRGs),构筑具有多相网络结构的阻尼橡胶材料.首先通过扫描电子显微镜(scanning electron microscopy,SEM)和原子力显微镜(atomic force microscopy,AFM)观察所制备集成材料的微观形貌,然后探究了FRGs多种组合对橡胶样品的动态性能的影响.结果表明,基于FRGs集成的多组分样品呈典型的“海-岛”多相结构,在保持每种FRGs组分相对独立的黏弹特性的同时,通过有效的界面反应实现黏弹特性的集成.进一步地,通过调控FRGs的网络结构参数和相对含量实现了各组分损耗峰的有序组合,获得一种多相结构的宽温域阻尼橡胶材料,其在吸音降噪方面展现出较好的应用潜力.此外,该多相阻尼材料还兼具优异的力学性能和吸能减震能力.本文工作基于传统橡胶工业原料和共混工艺,提出了一种简单易行、可规模化生产的橡胶阻尼材料制备新策略,不涉及复杂合成与改性,为发展高性能橡胶阻尼材料提供了新思路.展开更多
文摘橡胶减振装置在铁道运输系统中是必不可少的部件。基于将橡胶结构大变形和高阻尼特性考虑在内的自然频率域(NFR-Natural Frequency Region)方法,针对实际工业减振产品CUS单元在整个冲击过程中的动力响应测试,分别用2种模拟冲击质量体的有限元模型(点质量模型和实体模型)进行较详尽的分析,评估实体橡胶减振系统的时域冲击响应,所模拟的结果和测试数据吻合良好。可为有关工作提供参考,有助于更准确地模拟橡胶减振系统的动力响应,从而加快和优化设计过程。
文摘The compatibility of the IIR damping material was studied by use of DSC and DMA methods.The results is that the compatibility is very good between IIR and the resin vulcanizing reagent and there is only one mount in the charts of DSC or DMA.The studies of the results is very significant for the study on the damping characteristic of the damping materials.At the same time,we also discussed the reason through analysing the two molecular structures.
基金Projects(51775277,51775265)supported by the National Natural Science Foundation of ChinaProject(190624DF01)supported by Nanjing University of Aeronautics and Astronautics Short Visiting Program,China。
文摘A dynamic model of a flexible rotor supported by ball bearings with rubber damping rings was proposed by combining the finite element and the mass-centralized method.In the proposed model,the rotor was built with the Timoshenko beam element,while the supports and bearing outer rings were modelled by the mass-centralized method.Meanwhile,the influences of the rotor’s gravity,unbalanced force and nonlinear bearing force were considered.The governing equations were solved by precise integration and the Runge-Kutta hybrid numerical algorithm.To verify the correctness of the modelling method,theoretical and experimental analysis is carried out by a rotor-bearing test platform,where the error rate between the theoretical and experimental studies is less than 10%.Besides that,the influence of the rubber damping ring on the dynamic properties of the rotor-bearing coupling system is also analyzed.The conclusions obtained are in agreement with the real-world deployment.On this basis,the bifurcation and chaos behaviors of the coupling system were carried out with rotational speed and rubber damping ring’s stiffness.The results reveal that as rotational speed increases,the system enters into chaos by routes of crisis,quasi-periodic and intermittent bifurcation.However,the paths of crisis,quasi-periodic bifurcation,and Hopf bifurcation to chaos were detected under the parameter of rubber damping ring’s stiffness.Additionally,the bearing gap affects the rotor system’s dynamic characteristics.Moreover,the excessive bearing gap will make the system’s periodic motion change into chaos,and the rubber damping ring’s stiffness has a substantial impact on the system motion.
文摘通过在橡胶基体中集成多种功能性橡胶颗粒(FRGs),构筑具有多相网络结构的阻尼橡胶材料.首先通过扫描电子显微镜(scanning electron microscopy,SEM)和原子力显微镜(atomic force microscopy,AFM)观察所制备集成材料的微观形貌,然后探究了FRGs多种组合对橡胶样品的动态性能的影响.结果表明,基于FRGs集成的多组分样品呈典型的“海-岛”多相结构,在保持每种FRGs组分相对独立的黏弹特性的同时,通过有效的界面反应实现黏弹特性的集成.进一步地,通过调控FRGs的网络结构参数和相对含量实现了各组分损耗峰的有序组合,获得一种多相结构的宽温域阻尼橡胶材料,其在吸音降噪方面展现出较好的应用潜力.此外,该多相阻尼材料还兼具优异的力学性能和吸能减震能力.本文工作基于传统橡胶工业原料和共混工艺,提出了一种简单易行、可规模化生产的橡胶阻尼材料制备新策略,不涉及复杂合成与改性,为发展高性能橡胶阻尼材料提供了新思路.
