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.

磁性（MR）材料是高级材料，可以使用施加的磁场来控制流变学行为。 MR材料可以处于液体（MR流体）或固体（MR弹性体）状态。 MR流体通常由微米大小的可磁性极化颗粒（通常是羰基铁颗粒）组成，这些颗粒分散在矿物质或硅油等载体培养基中。当暴露于磁场时，这些磁性偶极子沿着磁通量的线对齐，从而导致MR流体从自由流动的粘性液体变为具有可控屈服强度在毫秒级的屈服强度的半固体。 MR流体也可以限制在吸收矩阵中，例如通过毛细管作用的海绵，形成MR流体泡沫。 MR弹性体是橡胶状的材料（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它们成为新一代高带宽半活动设备的吸引力材料，可以有效地用于改善在不可预测的环境变化下自适应结构系统的性能。 MR材料可以有效地用于控制频率广泛的振动和结构出生的噪声，从而可以设计下一代地面，航空航天和海洋车辆，它们在符合乘客舒适的标准时具​​有成本效益和可靠性。为了有效地设计这些基于M的自适应结构，在不同的磁场，激发的频率和振幅以及温度下，对MR材料的动态行为的基本理解至关重要。考虑到这一点，需要提出的设备来对各种MR材料的行为进行基本和系统的研究，这些材料在不同的磁场强度和不同的磁场和后产物区域的外部激发方面进行了不同。请求的磁透仪是一种独特的装置，可以表征MR材料在广泛的激发频率和振幅下的行为，并且在应用外部均匀磁场强度下的温度可以达到1 Tesla。可以使用建议的设备研究MR材料的线性和非线性粘弹性及其在后产物区域的粘塑性。这最终将导致构成模型的发展，这些模型可以准确地表征不同工作区域中MR材料的流变行为，因此可以有效地用于建模新型的基于MR的自适应结构在不可预测的外部激发下。