A state-of-the-art test equipment for characterization of advanced rheological materials

用于表征先进流变材料的最先进的测试设备

• 批准号: RTI-2017-00751
• 负责人: Sedaghati, Ramin
• 金额: $ 8.59万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616759
• 关键词: state; art; test; equipment; characterization

Magnetorheological (MR) materials are advanced materials whose rheological behavior can be controlled using the applied magnetic field. MR materials can be in liquid (MR fluids) or solid (MR elastomers) states. MR fluids are typically composed of micron-sized magnetically polarizable particles (typically carbonyl iron particles) dispersed in a carrier medium such as mineral or silicone based oils. When exposed to a magnetic field, these magnetic dipoles align themselves along the lines of magnetic flux causing the MR fluid to change from a free-flowing viscous fluid to a semi-solid with controllable yield strength in the order of milliseconds. MR fluids can also be confined in an absorbent matrix such as sponge by capillary action to form MR fluid foams. MR elastomers are rubber-like materials (magnetic particles are suspended in a solid polymeric medium) whose modulus can be adaptively controlled. The ability of MR materials to provide simple, quiet and rapid-response interfaces between electronic controls and mechanical systems have made them attractive materials for new generation of high bandwidth semi-active devices which can be efficiently used to improve the performance of adaptive structural systems under unpredictable environmental changes. MR materials can be effectively utilized to control vibration and structure-born noise in wide range of frequencies and thus allow to design next generation of ground, aerospace and marine vehicles which are cost-effective and reliable while meeting the standards for passenger comfort. To effectively design these MR-based adaptive structures, fundamental understanding of the dynamic behaviour of MR materials under varying applied magnetic field, frequency and amplitude of excitations as well as temperature is of paramount importance. Considering this, the proposed equipment is needed to conduct fundamental and systematic study on the behavior of all types of MR materials under varying intensities of magnetic field and varying external excitations in both pre-yield and post-yield regions. The requested magneto-rheometer is a unique device to characterize the behavior of MR materials under wide range of excitation frequencies and amplitudes, and temperature under the application of external uniform magnetic field intensities which can reach up to 1 Tesla. The linear and nonlinear viscoelastic properties of MR materials as well as their viscoplastic behavior in post-yield region can be investigated using the proposed equipment. This will eventually lead to development of constitutive models that can accurately characterize the rheological behavior of MR materials in different operating regions and thus can be effectively used in modeling of novel MR-based adaptive structures under unpredictable external excitations.

磁流变（MR）材料是一种利用外加磁场控制其流变行为的先进材料。MR材料可以处于液体（MR流体）或固体（MR弹性体）状态。MR流体通常由分散在载体介质（例如矿物油或硅酮基油）中的微米尺寸的可磁极化颗粒（通常为羰基铁颗粒）组成。当暴露于磁场时，这些磁偶极子自身沿着磁通线对准，从而导致MR流体从自由流动的粘性流体变为具有毫秒级的可控屈服强度的半固体。MR流体还可以通过毛细作用被限制在吸收性基质（诸如海绵）中以形成MR流体泡沫。MR弹性体是橡胶状材料（磁性颗粒悬浮在固体聚合物介质中），其模量可以自适应地控制。MR材料在电子控制和机械系统之间提供简单、安静和快速响应接口的能力使其成为新一代高带宽半有源器件的有吸引力的材料，这些器件可以有效地用于改善不可预测环境变化下的自适应结构系统的性能。MR材料可以有效地用于控制宽频率范围内的振动和结构噪声，从而允许设计下一代地面，航空航天和海洋车辆，这些车辆具有成本效益和可靠性，同时满足乘客舒适度标准。为了有效地设计这些基于MR的自适应结构，对MR材料在变化的外加磁场、激励频率和振幅以及温度下的动态行为的基本理解是至关重要的。考虑到这一点，所提出的设备需要进行基础和系统的研究在不同强度的磁场和不同的外部激励下的所有类型的MR材料的行为在屈服前和屈服后的区域。所要求的磁流变仪是一种独特的设备，用于表征MR材料在宽范围的激励频率和振幅下的行为，以及在施加可达1特斯拉的外部均匀磁场强度下的温度。利用该装置可以研究磁流变材料的线性和非线性粘弹性以及屈服后的粘塑性行为。这将最终导致本构模型的发展，可以准确地描述流变行为的MR材料在不同的操作区域，从而可以有效地用于建模的新型MR为基础的自适应结构在不可预测的外部激励。