減震器活塞桿液壓式耐久實驗臺的說明書畢業論文-資料下載頁

　　

【正文】 ter model.Lang altogether contained 83 parameters in the late1970s establishment39。s some double barrelled like suspension fork shock absorber39。s lumped parameter model, used in studying the shock absorber highfrequency response distortion question. He uses simplified the vaporization and the liquefied model describes in the work room to mix in the physical change which the gas occurs, realizes the shock absorber characteristic simulation using the analogous circuit.In the lumped parameter model needs valve39。s characteristic expression for valve39。s current capacity and the valve both sides pressure difference functional relations. Usually uses in the engineering fluid dynamics through each throttle hole39。s current capacity with its both sides pressure difference39。s relations the semirational formula establishment. The discharge chamber and in the restoration room39。s model must express between the cavity indoor fat liquor pressure and the piston kinematics parameter relations, usually must consider that the fat liquor the condensibility, it is causes the shock absorber velocity characteristic to present the sluggish phenomenon the substantial clause. The pensated chamber model must express between its internal fat liquor pressure and the volume relations. If the consideration gas mixes in the fat liquor to cause the shock absorber characteristic to give rise to the distortion problem, then needs to establish various cavities room fuelair mixture to have the physical change to cause the pressure volume characteristic to change the model. According to the mass flow conservation equation, relates various cavities room and throttle valve39。s current capacity model, constitutes the plete shock absorber model.When establishes the above lumped parameter model, supposes various cavities indoor fat liquor pressure distribution is even. But in fact generally is the inhomogeneous, especially nearby the throttle valve the region, this causes the model error inevitably. Some essential model parameter like cushion valve piece group39。s amount of deformity, the discharge coefficient and so on must obtain by the experiment test. From the establishment model mostly tests the result using the experiment to obtain partial or the plete model parameter, therefore is not advantageous in the design stage forecast shock absorber characteristic.Along with putation technology39。s development, uses the numerical method establishment and the solution shock absorber distribution parametric model possibly bees gradually. If uses the FFA method and CFD method analysis elastic structure dynamics and the hydrodynamics characteristic separately, deposes the fluid solid coupling dynamics question for many step noncoupling question solves, then may increase the model precision to reduce to the level of dependency which tests tests. Along with the class solid coupling dynamics analysis theory and putation technology39。s development, oneself has the possibility to use has FSI (fluidstructure interaction, class solid coupling) analyzes the function the finite element analysis tool to solve the shock absorber fluid solid coupling nonlinear dynamics question. parametrization modelIn the late 80s, Karadayi and Masada reveal Lang the model, although can express the shock absorber well the nonlinear response, but too plex, is not suitable uses in the automobile systems dynamics and the vibration simulation analysis. In order to establish one kind both to be able to express the shock absorber sluggish characteristic and a more concise model, they used equivalent have changed into the shock absorber by the elastic element, the damping element, the gap and the friction element and so on mechanical model which bined. In the model does not consider the shock absorber the actual structure and the interior work process. Part39。s mechanics characteristic already may be linear may also be misalignment, its posite system can express the shock absorber the misalignment dynamic characteristic. The Karadayi modelling method to establish the shock absorber the few parameter misalignment model to explore an effective way, but its model simulation result only could tally well under the shock absorber low frequency movement operating mode with the experimental result.Besinger and Cole and so on the late 90s this modelling method should. Uses in the heavy vehicle suspension fork shock absorber the modelling, has used the misalignment elasticity and the damping element, its model simulation result is smaller than in the piston motion frequency 10Hz, the speed is smaller than in the 1m/s scope, tests the result with the experiment to tally well.Uses has several kind of equivalent parametrization models which the different mechanics characteristic physics unit construction bees: (a) only bees by linear elasticity part K and the linear damping part C series。 (b) increased a friction element Psi。 (C) in (b) in the foundation increased a gap part Epsilon. Between the equivalent parametrization model39。s physical part and the influence shock absorber characteristic actual factor has certain corresponding relationships: The elastic element corresponds in the throttle valve is the elastic element, the fat liquor or the fuelair mixture condensibility, the cylinder tube39。s elasticity as well as the shock absorber both sides connects hinge39。s rubber bush elastically and so on bined action effect。 The damping element corresponds in the fat liquor flows through the damping action which the throttle hole produces。 The friction element corresponds to the movement vicebetween friction。 The gap part corresponds to the throttle valve and the fat liquor movement lag as well as when the shock absorber heading change possibly appears spatial regulation. In the model various physical part39。s parameter value may by the experiment metrical data fitting.May use the different unit construction in view o