磁流變體之介觀理論研究(1/2)

Abstract

近年來隨著科技的日新月異，面對材料介尺度的問題已不可避免。另一方 面，磁流變流體的應用研究隨著其性能的提升而受到眾人的注目。為了進一步了 解磁流變流體在磁場下之力學行為，以做為爾後在土木工程領域上應用的依據， 此外並期望能進入介尺度的研究領域而不與科技進展相脫節，本研究計畫之主要 目的在採用介觀理論探討磁流變流體的行為。 磁流變流體與液晶材料或超導體具有極密切之相似性，三者皆具有內部之 結構，而超導體乃最先為研究人員利用介尺度所探討之材料，其在介尺度下之特 有表徵為表面效應、小尺寸效應和宏觀量子效應。磁流變流體與液晶材料亦可利 用介觀理論以探討其行為。由現有文獻可知液晶材料之介觀理論可統合各種液晶 材料之宏觀理論，因此利用介觀理論可擴展磁流變流體的宏觀理論，並為其找到 力學基礎。 建構宏觀與微觀之橋樑為研究人員之長遠目標，磁流變流體的三種尺度之研 究可做為分析其他新型材料之範例，亦為了解力學體系運作之途徑。其研究成果 預期將為工程界與學界提供有用之資訊與思維方法，並可做為進一步努力的方向 與準則。

Recently, with the progress of technology, we will inevitably face some problems of materials on the mesoscopic scale. On the other hand, with the promotion of performance of magnetorheological (MR) fluids, the researches for application of these kinds of fluids have attracted much attention. To get a further understanding of how the MR fluids respond in the presence of a magnetic field, to provide a direction to which leads the application of these fluids in the field of civil engineering, and to enter the research realm of mesoscopic scale, we will adopt the mesoscopic concept to deal with the mechanics of MR fluids. MR fluids have a close resemblance with liquid crystals and superconductors in that they all possess internal microstructures. Superconductors have been studied on the mesoscopic scale whose representations include the surface, small scale, and macroscopic quantum effects. MR fluids and liquid crystals can also be analyzed by the mesoscopic approach. It is well known that the different macroscopic theories of liquid crystals can be deduced from the mesoscopic theory. Therefore, we can expand the development of macroscopic theories and find the mechanical base of macroscopic approach by the use of mesoscopic concept. Constructing the bridge between the microscopic and macroscopic theories is a long-term goal for researchers. The three scales of studies in MR fluids can serve as a paradigm of studying new sorts of materials and as a tool of understanding the operations of mechanics system. We expect that this research will provide related science and the engineering realm with useful information and thoughts and with a further way for advance studies.