| Hydraulic flexible hose is the indispensable fluid delivery element of hydraulic system, Hydraulic flexible hose vibration in unsteady flow excitation, will inspire Hydraulic flexible hose and fluid Fluid-structure coupling effect. Fluid-structure coupling effect will cause the following consequences。 The frist, Fluid-structure coupling effect will reduce the natural frequency of the pipe system; Second,Fluid-structure coupling effect will Increased Hydraulic flexible hose vibration;Third, Fluid-structure coupling effect will Increased fluid Fluctuate。 the piping system natural frequency Reduce, Will lead when in the the engineering design process the piping natural frequency calculation is inaccurate, Causing resonance of the piping system, Severe, can lead to the pipe rupture. The Severe vibration of pipe will exacerbate fatigue damage, reduce the life of the pipeline, At the same time, The Severe vibration of pipe will result pipe connection parts loose, and even lead to the pipe joints loss and the sealing failure.The oil pressure Dramatic Fluctuate will cause damage to the hydraulic components, hydraulic flexible hose Compared with ordinary hydraulic straight pipes,Because of its unique environment, hydraulic hose often in a bent-shaped body. because the presence of Burdon coupled, the hydraulic hose which is in bending state Compared with hydraulic straight pipes,the vibration of hydraulic hoses is more intense.Therefore, in order to study the method for reducing the hydraulic flexible pipe vibration, let the layout of hydraulic pipes rational,extend the hydraulic pipes and hydraulic software service life,Improve the hydraulic componen performance and precision, this paper carried out the following studies.The frist, Using Bernoulli- beam model, Through stress analysis of the fluid unit and pipe unit,Derived the mathematical model of hydraulic flexible hose which is in the unsteady fluid excitation, Through simplified, Has been the mathematical model of Hydraulic flexible hose which is in the pulsation pressure and hydraulic shock excitation, provides a theoretica basis of the hydraulic pipe FEM analysis.The Second, In order to study the hydraulic fluid-structure coupling flexible piping vibration characteristics of the fluid excitation, and the factors affecting hydraulic fluid-structure coupling flexible piping vibration characteristics, the paper through three simulation design to hydraulic flexible pipe in the hydraulic fluid excitation coupled vibration characteristics were studied. Design Option One: Through the flexible tubing hydraulic fluid-structure coupling vibration characteristics constant flow and pulsatile flow excitation, and found that the hydraulic fluid-structure coupling vibration characteristics of the pipeline slight pulsating flow excitation than the hydraulic pipes constant stream flow excitation solid coupling vibration characteristics more intense. By loading different pipe inlet constant flow rate, the simulation calculation and analysis, found that the vibration characteristics of fluid-structure coupling with the inlet end of the pipeline will increase the flow rate increased. Displacement curve obtained maximum amplitude and pulse frequency pulsating flow pipe vibration excitation between, the influence of the frequency of the vibration characteristics of the pipeline. Design Option Two: Research constant flow excitation vibration characteristics of the hydraulic fluid-solid coupling of different radii of curvature of the flexible pipe, and found that with the smaller radius of curvature, fluid-structure coupled vibration pipeline will be more intense. Relationship has been the largest displacement amplitude and frequency of three hydraulic radius of curvature of the flexible pipe between model, found that the smaller the radius of curvature of the lower resonance frequency of the pipe, the resonance amplitude greater, indicating the smaller radius of curvature, the pipeline fluid-structure coupled vibration more intense. Design Option third: Research Flow solid coupling constant excitation vibration characteristics under different hydraulic pipe wall thickness of the flexible pipe, flexible pipe wall thickness was found to increase the hydraulic fluid-structure coupling will reduce the vibration characteristics of the pipeline. Obtain the relationship between the different wall thicknesses of flexible conduit midsection hydraulic vibration displacement between the maximum amplitude and frequency, was found to increase the wall thickness, the pipe resonance frequency increases, the amplitude of the resonance pipe decreases, indicating increasing the wall thickness will reduce the pulsation pipeline flow excitation fluid-structure interaction vibration. Design Option fourth: studies of hydraulic shock incentives, impact pressure and pipe wall thickness of the pipe in coupled vibration characteristics. Obtain a hydraulic impact excitation, hydraulic vibration flexible pipe with increasing shock pressure exacerbated, but because the fluid can quickly share the vibrational energy of solids, thus piping vibration damping faster. And hydraulic vibration flexible pipe wall thickness and increased with the decrease, the thinner the pipeline, the more severe vibration, fluid can quickly share the vibrational energy of solids, thus the faster the vibration damping piping conclusions. |
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