A specially designed fluid damper used as negative shock pulse generator in the shock resistance test system to dissipate the shock input energy in transient time duration is presented. The theoretical modeling based ...A specially designed fluid damper used as negative shock pulse generator in the shock resistance test system to dissipate the shock input energy in transient time duration is presented. The theoretical modeling based on the three-dimensional equation of heat transfer through a fluid element is created to predict the viscous heating in the fluid damper under shock conditions. A comprehensive experimental program that investigates the problem of viscous heating in the fluid damper under different shock conditions is conducted on the shock test machine to validate the analytical expression. Temperature histories for the fluid within the damper at two locations, the annular-oriflce and the-end-of stroke of the damper, are recorded. The experimental results show that the theoretical model can offer a very dependable prediction for the temperature histories in the damper for increasing input velocity. The theoretical model and experimental data both clearly indicate that the viscous heating in the damper is directly related to the maximum shock velocity input and the pressure between the two sides of the piston head.展开更多
Based on the well-known quarter car representation of the automobile suspension,this paper deals with the effect of shock absorber outer performance degradation(OPD)on vehicle ride comfort and driving safety.Based on ...Based on the well-known quarter car representation of the automobile suspension,this paper deals with the effect of shock absorber outer performance degradation(OPD)on vehicle ride comfort and driving safety.Based on an elastici- ty model of a flat circular plate having a central hole,a program for the determina- tion of shock absorber outer performance(SOP)has been developed. Based on a hy- drodynamic theory,principles for the inter performance design of shock absorbers are presented to ensure expected SOP and the concept of critical velocity for the pre- vention of OPD is studied.By analysing the mechanism of degradation,a method for the elimination of shock absorber degradation is offered for practical structural design,i.e,the structural design of dual-tube gas charge shock absorbers.A good deal of experimental data,are presented to prove the theoreticaly studies.展开更多
In this paper, mathematical models and dynamic analyses for both SDOF and MDOF structures isolated with dampers are established and performed, and a comprehensive computation method is provided. The shock absorbing ef...In this paper, mathematical models and dynamic analyses for both SDOF and MDOF structures isolated with dampers are established and performed, and a comprehensive computation method is provided. The shock absorbing effect is illustrated through an example of a two DOF damper-isolated system excited by sinusoidal waves and actual ground acceleration input recorded in earthquakes. It is shown that most of the responses of the structure with dampers reduce greatly near the resonant zone, but acceleration is enlarged in the lower or higher frequency zone; among various parameters, the influence of frictional coefficient n is the most significant, that of damping ratio of the dampers , is the second, and that of stiffness coefficient of the dampers k, is the slightest.展开更多
基金Chinese Navy Warship Research Center(No.05131-1046)
文摘A specially designed fluid damper used as negative shock pulse generator in the shock resistance test system to dissipate the shock input energy in transient time duration is presented. The theoretical modeling based on the three-dimensional equation of heat transfer through a fluid element is created to predict the viscous heating in the fluid damper under shock conditions. A comprehensive experimental program that investigates the problem of viscous heating in the fluid damper under different shock conditions is conducted on the shock test machine to validate the analytical expression. Temperature histories for the fluid within the damper at two locations, the annular-oriflce and the-end-of stroke of the damper, are recorded. The experimental results show that the theoretical model can offer a very dependable prediction for the temperature histories in the damper for increasing input velocity. The theoretical model and experimental data both clearly indicate that the viscous heating in the damper is directly related to the maximum shock velocity input and the pressure between the two sides of the piston head.
文摘Based on the well-known quarter car representation of the automobile suspension,this paper deals with the effect of shock absorber outer performance degradation(OPD)on vehicle ride comfort and driving safety.Based on an elastici- ty model of a flat circular plate having a central hole,a program for the determina- tion of shock absorber outer performance(SOP)has been developed. Based on a hy- drodynamic theory,principles for the inter performance design of shock absorbers are presented to ensure expected SOP and the concept of critical velocity for the pre- vention of OPD is studied.By analysing the mechanism of degradation,a method for the elimination of shock absorber degradation is offered for practical structural design,i.e,the structural design of dual-tube gas charge shock absorbers.A good deal of experimental data,are presented to prove the theoreticaly studies.
文摘In this paper, mathematical models and dynamic analyses for both SDOF and MDOF structures isolated with dampers are established and performed, and a comprehensive computation method is provided. The shock absorbing effect is illustrated through an example of a two DOF damper-isolated system excited by sinusoidal waves and actual ground acceleration input recorded in earthquakes. It is shown that most of the responses of the structure with dampers reduce greatly near the resonant zone, but acceleration is enlarged in the lower or higher frequency zone; among various parameters, the influence of frictional coefficient n is the most significant, that of damping ratio of the dampers , is the second, and that of stiffness coefficient of the dampers k, is the slightest.
