轧机辊系垂直非线性参激振动特性分析_图文

1、 NOV 2009 JOURNAL OF V I BRATI ON AND SHOCK Vol . 28 No. 11 2009 Ana lysis on param etr ica lly exc ited non lin ear vertica l v ibra tion of roller system in rollin g m ills HOU D ong 2x iao, CHEN Hao, L I U B in, SH I Pei2 m ing, ZHAN G Yu 2cun ( College of Electrical Engineering, Yanshan Universi

2、ty, Hebei Q inhuangdao 066004, China Abstract: A vertical nonlinear parametrically excited vibration model of 4 2h rolling system was established, in con2 sideration of the nonlinear damp ing and nonlinear stiffness betw een working rolls . The analytic app roxim ate solution of par2 am etric resona

3、nces to corresponding main frequency, ultra harmonics and inferior harmonics were studied by using m ulti2 p le 2scales method, and the amp litude 2frequency characteristic equation was obtained. The stability character was dis2 cussed and the relationship s betw een stability and certain param eter

4、s were obtained. The vibrational characteristics of sys2 tem w ith nonlinear stiffness and nonlinear damp ing were analyzed. A s nonlinear stiffness varies, the amp litude jump ing phenomenon may appear and lead to instability of the system. The numerical sim ulation indicates the validity of the so

5、lu2 tion. Key words: rolling m ill; param etrically excited vibration; stability; m ain resonance vibration; ultra harmonics reso2 ( pp: 1 - 5 nance vibration Va lid ity test of rad ia ted no ise sources m odel of sh ip M EN G Chun 2x ia 1, 2 , YAN G S h i2e , ZHAN G L iang , L I Gu i2juan 1 2 2 (1.

6、 College of Under water Acoustic Engineering, Harbin Engineering University, Harbin 150001, China; 2. The Key Laboratory for Under water Scientific Test and Control Technology, Dalian 116013, China Abstract: U sually the radiated noise of the ship is measured only at near distance to ensure enough s

7、ignal to noise ratio. So it is highly important to study the modeling of the volum e source of ship. In order to show the validity of the sug2 gested model of radiated noise sources of ship at shallow wave guide, the radiated noise of a fishery ship was m easured. Experi m ental results show that th

8、e established model is effective, which means that the ship noise sources can be de2 scribed as some distributed multi2 poles along the ship. The conclusion is helpful to understand the internal characteristics of ship. ( pp: 6 - 8 Key words: radiated noise of ship; source model; validity test Con t

9、in uous stress m odel for beam s trea ted w ith active con stra in ed layer dam p in g WAN G M iao , M EN G Guang 1, 2 1 ( 1. State Key Laboratory of M echanical System s and V ibration, Shanghai 200240; 2. Departm ent of Engineering M echanics, Shanghai J iaotong University, Shanghai 200240, China

10、Abstract: Considering the effect of higher2 order shear deformation in thick damp ing layer, a new model called “continuous stress model” was p roposed for the ACLD structures . B ased on the Reddy s sim p lified higher2 order shear the2 ory, a three 2 order disp lacement field was app lied to descr

11、ibe the damp ing layer . So both the disp lacements and shear stresses are ensured to be continuous at the interfaces of three different layers . And the novel spectral finite element meth2 od ( SFEM was used to model a fully ACLD beam and comparisons were made bet w een the new model and the traditional M ead 2 M arkus model . It can be seen that the continuous stress model is better than the M ead 2 M arkus model on p redictions of natural frequencies and modal loss factors . Key words: