磁流變液(Magnetorheological Fluid)簡稱MR，它是由可極化的固體顆粒分散在絕緣溶劑中所形成的懸浮液，當有外加磁場的作用下，即可改變其內部結構及黏滯性。由於其具有反應速度快(毫秒量級)、阻尼係數可藉磁場改變的特性和不具複雜的設備，本文利用磁流變液的特性以設計出一組以MR緩衝器聯合即成之碰撞緩衝系統，並透過半主動的控制方法，使緩衝器在幾十微秒內吸收大量碰撞能量，車體可在不同的碰撞速度下於碰撞後均能以等減速度前進，因此減低車體於碰撞時所受的應變能而降低傷害。
以一輛歐洲進口轎車為例，汽車於低速及高速發生碰撞時，以加裝磁流變液碰撞緩衝系統與實車碰撞測試作比較，模擬結果顯示，加裝碰撞緩衝系統者可大幅的降低碰撞產生的最大作用力，亦即最大負加速度(車速高者比車速低者改善的多)。潰縮進去的距離都發生在緩衝器上，故車體本身不會產生正向變形，因此不致因車體破壞而擠壓車廂，使駕駛人及乘座者受傷，如此可有效提升汽車於發生正向撞擊時的安全性。

Magnetorheological Fluid(MR) is a suspension fluid formed by scattering polarizable solid granule in isolated solvents. Under the influence of outside magnetic field, it can change its inner structure and viscosity property. Owing to its quick reaction property(measured by milliseconds),damping coefficient can be changed through magnetic field without complicated equipment, its property can be designed into a collision bumper system which combined with MR damper, and by way of semi-active control method, damper can absorb much collision energy in several ten milliseconds and the car’s body collides in different speed could be decelerated to reduce the strain energy and damage during collision.
For example, a Europe produced car collides at high speed and low speed. Compared the car installed the collision bumper system and dosen’t, the result of this simulation shows the collision bumper system can greatly reduce the maximun collision force and deceleration (high speed is greater than low speed). Bumper system compressed; thus, car body wouldn’t generate normal deformation to injure driver and passenger, so it can efficiently improve car’s safety in normal collision.

1.任勇生,”智能材料在土木結構監測及振動控制中的應用”,太原大學理工大學學報,第 三卷第五期,2000
2. Load Materials Division, ”What Is the Difference Between MR And ER Fluid?” Presentation,2002,5.
3.Rabinow, J., “The Magnetic Fluid Clutch”, Electric Engineering Vol.67, pp.417-431, 1948.
4.Rabinow, J. “Magnetic Fluid Clutch”, National Bureau of StandardsTechnical News Bulletin, 32(4)54-60(1948).
5.Rabinow, J. “Magnetic Fluid Torque and Force Transmitting Device”, U.S. Patent 2,575,360 (1951).
6.Rosensweig, R.E., Kaiser, R. and Miskolczy. G., “Viscosity of Magnetic Fluid in a Magnetic Field”, J. Colloid and Interface Sci., Vol. 29, p. 4, 1969.
7.Shulman, Z. P., Kordonsky, V. I., Zaltsgendler, E. A., Prokhorov, I. V., Khusid, B. M. and Demchuk, S. A., “Structure, Physical Properties and Dynamics of Magnetorheological Suspensions”,Int. J. Multiphase Flow, Vol. 12, No. 6, pp. 935-955, 1986.
8. Nakatsuka, K., Yokoyama, H., Shimoiizaka, J. and Funaki. T. “Damper Application of Magnetic Fluid For a Vibration Isolating Table”, J. Magn. Mabn. Mater., Vol. 65, pp. 359-362, 1987.
9.Kordonsky, W. I., Shulman. Z. P., Gorodkin, S. R., Demchuk, S. A., Prokhorov. I. V., Zaltsgendler, E. A. and Khusid. B. M., “Physical Properties of Magetizable Structure- Reversible Media,”J. Magn. Magn Mater., Vol. 85, pp. 114-120, 1990.
10.Kordonsky, W.I., “Elements and Devices Based on Magnetorheological Effect,” Journal of Intelligent Material Systems and Structures, Vol. 4, pp. 65-69, 1993.
11.Kordonsky, W. I., “Magnetorheological Effect as a Base of New Devices and Technologies”, J. Magn. Magn. Mater., Vol. 122, pp. 395-398, 1993.
12.Nakatsuka, K., “Trends of magnetic fluid applications in Japan”, J. Magn. Magn. Mater., Vol. 122, pp. 198-394, 1993.
13.Weiss, K. D., Carlson, J. D. and Nixon, D. A., “Viscoelasric Properties of Magneto-and Electro- Rheological Fluids,” Journal of Intelligent Material System and Structures, Vol. 5, pp. 772-775, 1994.
14.Carlson, J.D. and Weiss, K. D., “A Growing Attraction to Magnetic Fluids”, Machine Design, pp.61-64, August 1994.
15.Fujita, T., Wada, Y., Obinata, G., Akagami, Y., Nishimura, S. and Ogasawara, Y., “Comparison of Frequency Characteristics in a Damper Using Magnetic Fluid, ER Fluid Dispersing Smectite and Mixed ER Magnetic Fluid”,Int. J. Modern Phy. B, Vol. 10, Mo. 2324, pp.3001-3010, 1996.
16.Ashour, O., Rogers, C. A. and Kordonsky, W.I., “Magnetorheological Fluids： Materials, Characterization and Devices”, Journal of Intelligent Material Systems and Structures, Vol. 7, pp. 123-130, 1996.
17.Jeon, D. and Park, C., “Vibration Suppression by Controlling an MR damper”, ERMR 97, International Conference on ERF, MRS and Their Applications, pp. 22-25, July 1997, Yonezawa, JAPAN
18.Jolly, M. R., Bender, J. W. and Carlson, J. D., “Properties and Applications of MR Fluids”, SPIE 5th Annual Int. Symposium on Smart Structures and Materials, San Diego, CA, 15 March, 1998.
19.卜遠程,“磁流變液之機械性質與消能機制的探討”, 博士論文, 國立台灣大學應用力學研究所, 1998.
20.S.J.McManus and K.A.St.Clair, ”Evaluation of Vibration and Shock Attenuation Performance of A Suspension Seat With A Semi-Active Magnetorheological Fluid With A Semi-Active Magnetorheological Fluid Damper.”, Journal of Sound and Vibration(2002) 253(1),313-327
21.Richard I.Emori,”Analytical Approach to Automobile Collisions,” SAE paper 680016,1968.
22.Kenneth.L.Cambell,”Energy Basis for Collision Severity, ”SAE paper 740565,1974.
23.Raymond .M.Brach,”Energy Loss in Vehicle Collisions,”SAE paper 871993,1987
24.Gustav A.Nystrom,Garrison Kost,and Stephen M.Werner, ”Stiffness Parameters for Vehicle Collision Analysis,“SAE paper910119,1991.
25.Tadanori Azuma,Hirotetsu Motobu and Koji Yoshioka, ”A study on a New Type of Isolator for Shock and Vibration Based on a Swinging Motion Mechanism-Part 2:New Bumper System,”SAE paper 921593, 1992.
26.P.K.Dellock and T.A.Sweder,” A New 5MPH Bumper System,”SAE paper 942277,1994.
27.Seong Sik Cheon,Jin Ho Choi and Dai Gil Lee, ”Development of The Composite Bumper Beam for Passenger Cars,”Composite Structures 32(1995)491-499
28.Helcio Onusic,Jose Augusto P Campos and Paulo Sergio P dos Santos, ”Considerations Concerning Vehicle Collisions Through Simplified Calculations of the Impact Forces,”SAE paper962324,1996.
29.Kazunari Mogami,Kenshi Fujiwara,Hiroki Yamamoto and Yasumi Itho, ”Frontal Crash Characteristics of Compact Car at a High Speed Collision,”SAE paper980553,1998.
30.Dagmar G.Buzeman,David C.Viano and Per Lovsund, ”Car Occupant Safety In Frontal Crashes:A Parameter Study of Vehicle Mass,Impact Speed,and Inherent Vehicle Protection, “1998 Elsevier Science Ltd.
31.S.W.Kirkpatrick, ”Development and Validation of High Fidelity Vehicle Crash Simulation Models,”SAE paper,2000-01-0627
32.王代華,“磁流變液（MR）的特性與應用研究綜述,” 第二屆全國電磁流變學術會議, pp. 25, 1998.
33.Lord Materials Division, “Designing with MR Fluids,” Engineering Note, December 1999.
34.Weiss, K. D., Carlson, J. D. and Nixon, D. A., “Viscoelastic Properties of Magneto- and Electro- Rheological Fluids,” Journal of Intelligent Material Systems and Structures, Vol. 5, pp. 772-775, 1994.
35.Nakano, M., Yamamoto, H. and Jolly, M. R., “Dynamic Viscoelasticity of a Magnetorheological Fluid in Oscillatory Slit Flow,” 6th Int. Conf. on ERF, MRS and Their Applications,pp. 22-25, July 1997, Yonezawa, JAPAN.
36.Kormann, C., Laun, M. and Klett, G., ” Actuator 94, 4th Int. Conf. on New Actuators,” eds. H. Borgmann and K. Lenz, Axon Technologies Consult GmbH, 271, 1994.
37.Jolly, M. R., Bender, J. W. and Carlson, J. D., “Properties and Applications of MR Fluids”, SPIE 5th Annual Int. Symposium on Smart Structures and Materials, San Diego, CA, 15 March, 1998.
38.Duclos, T. G., “Design of Devices Using Electrorheological Fluids, ”SAE Paper #881134, Future Transp. Techn. Conf. and Exp., San Francisco, CA, Aug 8-11, 1988.
39.Carlson, J. D., “The Promise of Controllable Fluids”, Actuator 94, 4th Int. Conf. on New Actuators, eds. H. Borgmann and K. Lenz, Axon Technologies Consult GmbH, 1994, pp. 266-270, 1994.
40.Lord Materials Division, “Magnetic Circuit Design,” Engineering Note, November 1999.
41.魏清芳，”磁流變液應用於飛機起落架之動態分析,”碩士論文,國立台灣科技大學機械工程研究所,2000.
42.Benjamin, Milwitzty, and Cook, F. E., “Analysis of Landing Gear Behavior,” NASA Report 1154, 1953.
43.Wahi, M. K. “Oil Compressibility and Polytropic Air Compression Analysis for Oleopneumatic Shock Strut,” Journal of Aircraft, Vol. 13, NO. 7, July. 1976, pp. 527-530.
44.黃靖雄”現代汽車底盤”,民83,全華科技圖書有限公司
45.吳橋林”福特汽車叢書(三)”,民75
46.Matthew Huang, “vehicle crash mechanics,”2002 by CRC Press LLC
47.Michael S. ”An Investigation into Vehicle Frontal Impact Stiffness, BEV and Repeated Testing for Reconstruction”SAE paper930899
48.Lord Corporation, “Rheonetic Linear Damper–RD-1001/RD-1004 Product Information Sheet,”(Lord Corp. Pub. No.PS RD-1001/4)1997.
49.Suresh B. Kudallur,Gary H.Conners,and Keith W. Buffinton, “Damping and Stiffness Control in a Mount Structure Using Electrorheological (ER) Fluids,”FED-Vol.205/AMD-Vol.190,
Developments in Electrorheological Flows and Measurement
Uncertainty,ASME 1994.