The design and simulation of magneto-rheological damper for. automobile suspension

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1 International Journal of Research in Enineerin and Science (IJRES) ISSN (Online): , ISSN (Print): Volue 3 Issue 9 ǁ Septeber. 15 ǁ PP.16-3 The desin and siulation of aneto-rheoloical daper for autoobile suspension Kan Lulu, Luo Yipin, Ren Honjuan (Collee of Autootive, Shanhai University of Enineerin Science, Shanhai, 16) Abstract: As the application of aneto-rheoloical (MR) daper in autoobile suspension sei-active control, accordin to the character of the MR fluid and the relations between the dapin force of MR daper and the structure paraeters, the new-type autoobile suspension MR daper was desined. At present, the desin ethod of MR daper is still depended on the experience of the desiner, which can't be calculated accurately. In this paper, after a review of the features and odels of MR aterials and devices, eoetrical desin and anetic circuit desin of MR daper were presented and discussed in detail, then the perforance of MR daper was analyzed by MATLA. Siulation results showed that the desin ethod of this autoobile suspension MR daper was feasible and the test perforance was satisfactory, which could eet the requireents of dapin syste for autoobile suspension and achieve the required adjustable rane of anticipative dapin force. The keyword: aneto-rheoloical daper; autoobile suspension; sei-active control I. Introduction Maneto-rheoloical(MR) daper is a sei-active control daper with aneto-rheoloical fluid(mrf) as the ediu, the external anetic field strenth can be chaned by the control of the input current, which can chane the rheoloical properties of the MRF in illiseconds, to realize the chane of the MRF in the fluid and the sei solid. Furtherore, it can provide controllable dapin force, which has the advantaes of siple structure, convenient control, fast response, sall power consuption, stron anti pollution ability and lare output force. The operatin odes of the autoobile suspension MR daper are divided into valve type, shear type and extrusion type accordin to the classification standards of the workin odes of the MRF. These operatin odes can also be used to desin a MR device, which is called a hybrid operatin ode. At present, it is urent to develop a autoobile suspension MR daper with reasonable structure and excellent perforance to proote its application in the vehicle enineerin field. The key in the desin of the MR daper is to ake full use of the excellent properties of the MRF. However, the desin theories of the MR daper are not perfect. In this paper, in order to further strenthen the research on the precise desin ethod of the MR daper, the desin and analysis of the MR daper for autoobile suspension had been copleted. II. Dapin force calculation odel and anetic circuit desin of the autoobile suspension MR daper.1 Rheoloical constitutive odel of MRF The behavior of the MRF is a visco-plastic fluid in the external anetic field. So far, there is no a sinle or siple constitutive equation can accurately describes the rheoloical properties of MR fluid, only several 16 Pae

2 epirical equations are in accord with the actual fluid in a certain rane. Two kinds of rheoloical odels of the ost widely used MRF are shown in Fi.1: inha odel and Herschel-ulkley odel. shear stress shear strain rate 1 shear thickenin( 1); inha( 1); 3 shear thinnin( 1); 4 Newton fluid Fi.1.Visco plastic odel of MRF inha odel [1] is a ost siple constitutive relation odel of MRF. The stress-strain relationship of odel is: sn( ) (1) Where is the yield strenth of MRF, H is the anitude of the anetic field, sn( ) is the sin function, is the shear strain rate and is the dynaic viscosity coefficient. Herschel-ulkley odel [] assued that the viscosity of the fluid was a power function associated with the shear strain rate : 1 ( K )sn( ) () where is the flow characteristic paraeter, K is the unifority coefficient, K >. Accordin to (), when 1, the viscosity will be reduced with the increase of, which describes the shear thinnin phenoenon of MRF. When 1, which is the inha odel. In the case of hih shear rate or hih anetic field strenth, Herschel-ulkley odel can consider the shear thinnin or shear thickenin phenoena occurrin in the post yield reion.. The dapin force calculation odels of MR daper In flow pattern, the dapin force of the MR daper consists of the dapin force P caused by the viscosity of MRF and the dapin force P caused by the anetic field. In shear pattern, the shear stress consists of the shear stress F caused by the viscosity of MRF and the shear stress F caused by the anetic field. In this paper, a pair of peranent anets are installed inside the MR daper, which will produce the correspondin repulsive force F c. When MR daper workin under ixed ode of valve type and shear type, 17 Pae

3 the total dapin force is: The desin and siulation of aneto-rheoloical daper for autoobile suspension F P P F F F c 1 QL c L Lw 1.5 A A V Lw A w al y 3 p p y (3) Where, Q V Ap, w R1, R R1, L l, c 3, cobinin those with (3): lap lap R1l 3 y 4 1 y 1( 1) F V V R A R R R R R R R al (4) where is the zero anetic field viscosity of MRF, L is the piston's lenth, Q is flow in the ap, is the ap's thickness, w is the piston's circuference, y is the yield stress, the value rane of the c is ~ 3 (when P P 1, c ; when P P 1, 3 c ), V is the relative speed of the plate, A p is the effective workin area of the piston, is the anetization of the peranent anet, the value rane of the correction factor c is 3~5, L is the ap between two peranent anets. strenth Accordin to (3), the ain factors that affect the dapin force of MR daper are: the axiu yield, volue flux Q, piston's lenth L and ap's thickness. The size of the dapin force is y inversely proportional to, is proportional to piston's lenth L.In order to increase the axiu dapin force, within the allowed rane of increasin L and decreasin. Therefore, this paper ainly focuses on the desin of these paraeters..3 The desin of anetic circuit syste of MR daper The perforance of MR daper ainly depend on its eoetrical size, anetic circuit and the perforance of MRF. In the case of the iven perforance paraeters of MRF, the key to desin a ood daper are the structure desin and anetic circuit desin of daper. In addition, it also includes dust, leakae, anetic separation, sealin, coolin and connection [3-4]. The purpose of anetic circuit desin of MR daper is to deterine the nuber of turns of the coil. In order to ake the anetic field strenth reach the axiu, the daper has larer controllable dapin force. In addition, the teperature of the coil shall not exceed the allowable value, the size of coil should be atched with the piston diensions. Accordin to the characteristics of MRF, the function of dynaic yield stress and anetic field strenth can be deterined: y H (5) 18 Pae

4 where and are the constants for specific aterials. The anetic circuit structure of MR daper is shown in Fi., in the case of no leakae anetic field, the anetic flux and the anetic field strenth of each part of Fi. are respectively: S i i (6) H i i (7) S i ri i where i is the anetic flux density of each seent, i is the pereability of each seent, is the closed anetic flux, is the pereability of vacuu, the each end surface area of anetic circuit. ri is the relative pereability of ediu, S i is Fi.. Scheatic diara of anetic circuit syste Assuin that the nuber of the field coils is N, the current in the coil is I. Accordin to apere loop theore, the anetootive force of the whole circuit[5]: NI (8) The calculation of each part of resistance is as follows: Manetic core: Manetic yoke: 4( L L ) R (9a) R 1 1 1d ln( D d) 1 L (9b) Cylinder: R 4( L L ) ( ) D3 D (9c) Workin ap: R ln( D D ) L 1 (9d) MRF Total reluctance: R R1 4R R3 4R (9e) 19 Pae

where i ri, ri is the relative pereability of each transission ediu, is the vacuu pereability,. 7 4 1 H Accordin to apere theore, (R1 R 4R3 4 R ), where is the anetic flux.

5 where i ri, ri is the relative pereability of each transission ediu, is the vacuu pereability, H Accordin to apere theore, (R1 R 4R3 4 R ), where is the anetic flux. Accordin to (6): in dapin passae of the MR daper, the relationship between the anetic flux and the anetic induction intensity is S. Synthesize above-entioned forula can be: S ( R 4 R R 4 R ) ( D D1 )(R1 4R R3 4 R ) (1) Accordin to (6), the anetic field strenth in the dapin rin can be obtained: H 4 ( D D ) (R 4R R 4 R ) (11) Cobinin (8) with (11) can be obtained: H NI S ( R 4 R R 4 R ) 1 3 (1) Accordin to (1), it can be known as lon as the structure paraeters and the nuber of field coil turns are confired, the anetic field strenth in the dapin rin can be copletely controlled by the input current. In this paper, the anetic field lines of the anetic circuit are shown in Fi.3, the anetic field lines are uniforly throuh the anetic field, there will be the correspondin dapin force. Fi.3. Distribution of anetic circuit III. The structure desin of MR daper As a echanical coponent, the desin of autoobile suspension MR daper should consider the strenth and riidity of the coponents. The ain contents of the structural desin are the selection of the aterial of the piston and cylinder, the deterination of the section size, the stress analysis of the coponent. In the desin, the shear yield strenth, viscosity coefficient and size paraeters of the cylinder of MRF are known, assue ap is, rane of value is 1~. Accordin to (3), the piston lenth is deterined, Pae

6 which needs to be adjusted accordin to the desin of anetic circuit. The desin should be based on the standard forula of the echanical desin for verifyin the cylinder thickness and the diaeter d of the piston rod, the forula is as follows: p D (13) d 4F (14) where p is the hihest workin pressure, the unit is Pa, D is the inner diaeter of cylinder, n b is the allowable stress of cylinder aterial, b factor, F is the axial force of the piston rod. In this paper, the structure of the MR daper is shown in Fi.4: is the aterial tensile strenth, n is the safety where 1 is the valve coponents, is the workin chaber A, 3 is the peranent anetic rin, 4 is the protection rin of excitation coil, 5 is the tensile peranent disk, 6 is the workin chaber, 7 is the liquid seal, 8 is the cap of daper, 9 is the piston rod, 1 is the storae cylinder of liquid, 11 is the workin cylinder, 1 is the storae cavity C of oil, 13 is the excitation coil, 14 is the piston coponents, 15 is the uide seat coponents, 16 is the sealin rin, 17 is the sprin coponents. Fi.4. Scheatic diara of the structure of the MR daper IV. Siulation analysis of MR daper In order to test the feasibility of the MR daper, the siulation analysis is carried out by MATLA. Accordin to the stroke of the daper and the workin condition of the recovery valve and the copression valve, the coputer siulation of the daper is perfored accordin to fi.5. 1 Pae

Start Input structure paraeters Input analo paraeters V N Y Calculation of recovery stroke Calculation of copress stroke Output external characteristic data Draw out external characteristic chart

7 Start Input structure paraeters Input analo paraeters V N Y Calculation of recovery stroke Calculation of copress stroke Output external characteristic data Draw out external characteristic chart Output results Fi.5. Flow chart of siulation of dapin characteristics Cobined with the desin paraeters of the MR daper, the siulation is based on the sinusoidal excitation. The axiu speed are respectively.39 s,.5 s, the aplitude are 5.. Different size of the siulation driven current are applied to the excitation coil, the rane of current is 3A. A record interval is.a, the reactive characteristic curve is shown in Fi.6. The siulation results show that with the increase of the coil current, the area of reactive power will increase, which shows that the dapin force of the daper will increase and the power dissipation will increase in the sae condition. Under the sae input current, the dapin force is proportional to the vibration velocity. When velocity is.39 s, the restorin force has increased fro 478.1N to 56.N. When velocity is.5 s, the restorin force has increased fro 68N to 693N. Siulation results showed that the MR daper accords with the technical requireents of the autootive suspension, the test perforance is desired and the dapin force attains the adjustable rane. (a) v.39 s, I.A (b) v.39 s, I.4A (c) v.39 s, I.6A Pae

(d) v.5 s, I.A (e) v.5 s, I.4A (f) v.5 s, I.6A Fi.6.Siulation curve of daper V. Conclusion The desin of MR daper refers to any subjects such as aterials, electroechanical, echanical and so on.

In this paper, the structure and anetic circuit of the MR daper are introduced in detail. Finally, the perforance of the MR daper is siulated.

8 (d) v.5 s, I.A (e) v.5 s, I.4A (f) v.5 s, I.6A Fi.6.Siulation curve of daper V. Conclusion The desin of MR daper refers to any subjects such as aterials, electroechanical, echanical and so on. The key is to establish the relationship between the dapin force and the eoetrical size of the daper and the anetic circuit paraeters. In this paper, the structure and anetic circuit of the MR daper are introduced in detail. Finally, the perforance of the MR daper is siulated. The results show that the siulation results are consistent with the theoretical data of the MR daper and accord with the technical requireents of the autoobile suspension, which eans that the desin ethod is feasible. Reference [1] Wereley NM,Pan L,Kaath GM. dealized Hysteresis Modelin of Electrorheoloical and Manetorheoloical Dapers[J].Journal of Intellient Material Systes and Structures, 1998, 9: [] Lee Du-Youn,Wereley N M. Quasi- Steady Herschel-ulkley Analysis of Electro- and Maneto-Rheoloical Flow Mode Dapers[J].Journal of Intellient Material Systes &Structures,,1: [3] Liao Chanron, Chen Weiin, Yu Miao. Discussion on Soe Technical Probles in the Desin of MR Daper[J]. Journal of Functional Materials and Devices,1(1): [4] Zhan Honjun, Liao Chanron, Chen Weiin. Study on the Relationship etween Manetic Circuit Desin and Perforance of MR Daper[J]. Journal of Instruent and Meter, 4(8): [5] Zhan Yuin, Qi oyun. Electroanetis[M].HeFei: Press of University of Science and Technoloy of China,. [6] Editorial Coittee of Standard Handbook of Machine Desin. Standard Handbook of Machine Desin (New Edition). Volue fourth [M]. eijin: China Machine Press,4: Pae

CHAPTER 3 QUADRUPLEX WINDING REDUNDANCY BRUSHLESS DC MOTOR

26 CHAPTER 3 QUADRUPLEX WINDING REDUNDANCY BRUSHLESS DC MOTOR 3.1 INTRODUCTION This chapter presents the desin of new quadruplex windin redundancy peranent anet brushless dc otor. The desin is carried