[ 4 ], [ 13 ], [ 3 ] [ 5 ] [ 7 ] China Academic Journal Electronic Publishing House. All rights reserved.

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1 9 JOURAL OF V IBRATIO AD SHOCK Vol. 9 o. 010,, (,, 3007 :,,,,,, : ; ; : O3; TB535: A,,,,,,,,,,, [ 1-6 ], [ 9, 10 ],, [ 11, 1 ], 1,,[ 1 ], [ ] [ 3 ] [ ],, [ 4 ], [ 5 ] [ 4 ], [ 6 ], [ 7 ],, [ 8 ],[ 4 ] [ 5 ], 111 [ 13 ],, (,, 1 : : ,, 198,,,,

2 010 9,1 ( a,1 ( b 1 ( a,,,, 4 kg,,,,,,,,,,,,,,,,, 5 kg,4 kg,1 kg, 4 1, 11 [ 14 ],, : f = 1 y l k + k 0 m (1 y, k, l, k 0, m,, 3,: [ 15 ], 3 3 ( a,, (1 (, 9. Hz Hz,94%,, 3 ( b,,, :, 3 ( b, M = sgn ( a - f ( 0. 03, , a, f, sgn ( a - f,,, :, = Y ( ( i, y i, ( j, y j, f - y a / P (3 P, y 0,, ( i, y i ( j, y j f

3 : 3, i < f < j, Y f, F y f,,,,,5 : y f = Y ( ( i, y i, ( j, y j, f = A cc, F y j - y i, ( j - f - i - y i (4 i A, : 4, 0 A cc A = M A F A (5, (5A cc A A, F A A,,, M A : Hz, Hz M A = [A 11 ] 1 [A 1 ] 1 = [A 1 ] 1 [A ] 4 ( x F, x F ( x F, x t l ( x F, x t s ( x F, x t l ( x t l, x t l ( x t s, x t l (6 : ( x i, x j = 1 m A ( x F, x t s ( x t l, x t s ( x t s, x t s 3 M A a = M T aa M aa = ( x a, x a (9 311 : x a 5, M, [ 16 ] a, :, 1 5 A cc a = M a F a = - F a (10 k a + j a a m a m a : m a ; k a ; a 5, B 5 :,, A cc, B = B 11 B 1 F B = B 1 B (6 + x i x j I A (7 : m A ; I A xy ; x F ; x t l, x t s A,, : A cc A A cc a = M A M aa M A a M aa F A F a (8 : F a, A cc a M aa, M A a, M aa : M aa = [ ( x a, x F ( x a, x t l ( x a, x t s ] T ; a ; ( 8, ( 10 A: A cc A = M A F A = [M A +M aa (M a - M aa - 1 M A a ] F A (11 B,,

4 d iag - k B 1 d iag A cc C = M C F C = [ ( x b l, x b s ] F C (13 F B ( x i, x j = - m b n < k ( x i < k ( x j (14 k =1 ( k (1 + j - f 1 = 1 k B = = 14. Hz; m A 300 (14, m b, k k,, < k k x b l, x b f s = 1 k B x s = = 19. Hz I A C f 1, f, :, F A b = - F B t A cc A b = A cc B t, F B b = - F C A cc B b = A cc C (15,6 6 ( a b, t,6 ( b ( 5, (1, (13(15, : : F c = H B H A F A t (16 A cc C = M C F C (17 H B = - (M C + B - 1 B 1 H A = - (B 11 + B 1 H B + A - 1 A 1 (18 (11 (5 [ 16 ],, [ 17 ][18 ], L (,,,, : eff = 0 lg L w ith L w ithou t = 0 lg X i- w ith i =1 X i- w ithou t i =1 (19,: m A = 300 kg, I A = kgm ; = 0. 5 kg,k B = /m, d iag d iag - k 3 B B = 0. 14, x t l = 0. 3 m, x t s = ( m; m c = 80 kg, C = 0. : k 3 B, 05; m a = 4 kg, a = ; x F = - 0. m,f = 1 C,, : xy : 6 (19, L w ith, L w ithou t 6,, X i - w ith, X i - w ithou t (14. Hz,, i, (19. Hz,, 31, 4 db,

5 : 5,,,,,,,,,, 7,, 4,,,,,,,,,,,, x a = m,, kg,,,, 8 8 9,,, 9 14 Hz19 Hz,,,17. 8 Hz (,,,,14 Hz Hz10 10 ( a,, 10 ( b, ( 10,,,, - 5 db (, (14 Hz 8 db,,:, ;, ;

6 , 5 10,, ;,0. 03;, 4: 1,, 94%,,,,,,,,,, 1 60, 8 db, [ 1 ] Franchek M A, Ryan M W, Bernhard R J. Adap tive passive vibration control[ J ]. Journal of Sound and V ibration, 1995, 185 (5 : [ ] agaya K, Kwrusu A, Ikai S and Shitani Y. V ibration con trol of a structure by using a tunable absorber and an op timal vibration absorber under autotuning control [ J ]. Sound and V ibration, 1999, 8 (4 : Journal of [ 3 ] Carneal J P, Charette F, Fuller C R. M inim ization of sound radiation from p lates using adap tive tuned vibration absorbers [ J ]. Journal of Sound and V ibration, 004, 70 ( 4-5 : [ 4 ] W alsh P L, Lamancusa J S. A variable stiffness vibration absorber for m inim ization of transient vibrations[ J ]. of Sound and V ibration, 199, 158 ( : Journal [ 5 ] KidnerM R F, B rennan M J. Varying the stiffness of a beam L ike neutralizer under fuzzy logic control [ J ]. V ibration and Acoustics, 00, 14 (1 : Journal of [ 6 ] B rennan M J. V ibration control using a tunable vibration neu tralizer[ J ]. Proceedings of the Institution of M echanical En gineers. Part C. M echanical Engineering Science, 1997, 11 ( : [ 7 ] liu J, L iu K F. A tunable electromagnetic vibration absorber: characterization and app lication[ J ]. Journal of Sound and V i bration, 006, 95 ( : [ 8 ] B rennan M J. Some recent developments in adap tive tuned vibration absorbers/ neutralisers [ J ]. 006, 13 (4-5 : Shock and V ibration, [ 9 ] Lvers D, W ilson R, Margolis D. W hirlingbeam selftuning vibration absorber[ J ]. Journal of Dynam ic System s, M eas urement, and Control, 008, 130 ( 3 : [ 10 ] Ebrahim ia B, Khameseea M B, GolnaraghiM F. Design and modeling of a magnetic shock absorber based absorber based on eddy current damp ing effect [ J ]. V ibration, 008, 315 (4-5 : Journal of Sound and [ 11 ] Rustighi E, B rennan1 M J, Mace B R. A shape memory alloy adap tive tuned vibration absorber: design and imp lementation [ J ]. Smart Materials and Structures, 005, 14 ( 1 : [ 1 ] Deng H X, Gong X L, W ang L H. Development of an adap tive tuned vibration absorber with magnetorheological elasto mer [ J ]. Smart M aterials and Structures, 006, 15: [ 13 ] Bonellol P, B rennan M J, Elliott S J. V ibration control using an adap tive tuned vibration absorber with a variable curvature stiffness element [ J ]. Smart Materials and Sructures, 005, 14 (1 : [ 14 ],,,. [ J ]., 005, 0 (4 : [ 15 ] agarajaiah S, Varadarajan. Short time Fourier transform algorithm for wind response control of building with variable stiffness TMD [ J ]. Engineering Structures, 005, 7 ( 3 : [ 16 ],,. [ J ]., 001, 37 (8 : [ 17 ],,,. [ J ]., 005, 4 (6 : [ 18 ],. [M ]. :, 006.

7 FEB 010 J OURAL OF V IBRATIO AD SHOCK Vol. 9 o. 010 M echan ica l v ibra tion absorber w ith tunable resonan t frequency and its v ibra tion a ttenua tion character istics XU Z henbang, GO G X inglong, CHE X ianm in (CAS Key Laboratory of Mechanical Behavior and Design ofm aterials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 3007, China Abstract: In order to imp rove working frequency band and damp ing effect of a vibration absorber, a new kind of vibration absorber was p resented, its resonant frequency could be adjusted in realtim e by adap ting its geometry parame ters. Its corresponding control method was also studied. Its vibration attenuation characteristics were analyzed theoretical ly. The simulation analysis of its dynam ical perform ance according to its theoretic model was performed w ith the transm is sion mobility m ethod. The dynam ic p roperties of the absorber were also characterized on a m ultip le modal experimental p latform. The experimental results matched well w ith the theoretical ones, they indicated that this kind of absorber can at tenuate vibration well in the whole frequency range. Key words: vibration absorber w ith tunable resonant frequency; vibration control; multip le modal vibration (pp: 1-6 M oda l character istics of a large span ra ilway cablestayed br idge CHE Ruilin 1,, 3, ZE G Q inyuan 3, HUA G Yunqing, X IA G Jun 3, W E Ying 3, X IAO Yingxiong 1, GUO X iaogang 1, ZHA G Junyan 1 ( 1. College of Civil Engineering & Mechanics, Xiangtan University, Xiangtan , China;. School ofmathematics & Computational Science, Xiangtan University; 3. College of Civil A rchitecture, Central South University, Changsha , China Abstract: A 3D finite element model of a whole bridge was built up. The characteristic equation of its free vibration was solved with subspace iteration method. The changing trend of natural frequencies and vibration modes of the whole bridge without or with a train was computed and analysed. The results of simulation and calculation showed each natural frequency of the whole bridge with a train was lower than the corresponding one of the whole bridge without a train. Moreover, vibra tion modes were changed into spatial coup led modes of vertical bend and lateral bend and torsion from ones in independent vertical and horizontal p lanes. The influences of the train different parking position and diffenert length on natural frequen cies of the cablestayed bridge were also studied. W ith change of parking positions, natural frequencies of the whole bridge with a train fluctuated. W hen the train entered or left the bridge, natural frequencies of the whole bridge monotonously dropped or rose respectively; when the train stopped in the m iddle of the bridge or near the bridge tower, natural frequencies of the whole bridge would have extreme points. W ith variety of the number of trailing vehicles, natural frequencies of the whole bridge changed too. It was shown that natural frequencies of the whole bridge should drop while the number of trai ling vehicles increased. However, the changing trend of natural frequencies was not influenced by the number of trailing vehicles. Key words: railway cablestayed bridge; FEM; natural vibration frequency; vibration mode ( pp: 7-10 Im pactdam p ing stud ies for in tegra l shroud blades of a turb ine mach inery LU X uxiang 1,, HUA G Shuhong 1, L IU Zhengqiang, L I L uping, XU D am ao (1. School of Energy and Power Engineering, Huazhong University of Science and Technology, W uhan , China;. School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha , China Abstract: Integral shroud blades with a contactimpact damp ing structure in tip s have advantages of vibration re duction, convenient installation and low p recision for manufacturing. They were successfully app lied in stream turbines for safe operation many years ago. But, the study on the damp ing mechanism and damp ing effect of such a structure was rath er lim ited. Com bined w ith study developm ents of vibroimpact theory, the research situation of integral shroud blades was