磁流變液是一種新式的智慧型材料，是由非導磁流體、易磁化微細粉末及分散劑所組成。當外加磁場輸入時，磁流變液在數微秒內，從牛頓流體變為賓漢塑性體 (Bingham plastic)，且連續、迅速、可逆及控制容易，故磁流變液阻尼器是理想的半主動控制元件。本文設計一流動式磁流變液阻尼器，使用Magneto 磁路分析軟體，模擬磁場效應對磁流變液的影響，並計算出較佳磁流變液阻尼器的磁迴路。建立一流動式磁流變液阻尼器的動態方程式，使用Lord 公司製的磁流變液，分析磁流變液阻尼器的特性。製造流動式磁流變液阻尼器，並使用避震器特性測試台量測流動式磁流變液阻尼器的特性。由實驗結果顯示，流動式磁流變液阻尼器有良好的控制特性。

Magneto-rheological (MR) fluid is a novel, smart material. MR fluid
is composed of dielectric fluids, magnetic micro-particles and surfactants.When an external magnetic field is applied, MR fluid changes from Newtonian fluid into a Bingham plastic in a few milliseconds, continuously,rapidly, reversibly, and controllably. Therefore, MR dampers are ideal semi-active control elements.In this paper, an MR damper of flow mode was designed. Magneto V64 software was used to analyze the magnetic circuit and field strength of the MR damper. The MR fluid was MRF-132DG made by Lord Company. From the results of magnetic circuit analysis and the shear stress characteristics of the MR fluid, we can obtain the relationship between the magnetic field and the yield stress of the MR fluid. The dynamic equation of the MR damper was built up to analyze the damping characteristics. A flow mode MR damper was fabricated and tested using a dynamic test rig, and the results were obtained in the form of force vs. velocity and force vs. displacement plots. The results show that the MR damper of flow mode has good control characteristics and yields energy savings.