شبيه سازي، ساخت و تست يك نمونه دسته موتور سيالاتي

چكيده انگليسي :

Simulation Prototyping and Testing of a Fluid Engine Mount Taghi Feyzi t feizi@me iut ac ir Date of Submission 2011 06 08 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohsen Esfahanian mesf1964@cc iut ac irAbstract The ideal engine mounting system should isolate engine vibration induced by engine disturbing forcein the range of engine speed and also prevent engine bounce caused by shock excitation This implies thatthe dynamic stiffness and damping properties of an ideal engine mount should be dependent on thefrequency and amplitude of the input excitation Conventional elastomeric mounts don t meet all therequirements of the ideal design and can only offer a tradeoff between static deflection and vibrationisolation because their dynamic properties is almost constant with the amplitude and frequency of theexcitation Passive hydraulic engine mounts because of their frequency and amplitude dependent dynamicproperties provide a better performance compared with elastomeric mounts espessialy in low frequencyexcitation To solve some problematic aspects of the passive hydraulic mounts and to improve theirdynamic performance further semiactive vibration control techniques have been applied to enginemounting designs Furthermore with the development of modern vehicle designs such as hybrid vehiclesand variable engine management systems which have different operational modes more sophisticatedengine mounting systems such as semiactive engine mouns are required to effectively response to the eachoperational mode Semiactive mounts can alter their response during operation i e damping and stiffnessto some extent Currently semiactive mounts rely on changes in geometry of the flow paths or on changesin properties of the working fluid As changes in geometry of the flow paths in real time require rathercomplex actuation mechanisms to be incorporated in the mount it is more desirable to be able to change themount response through changes in the working fluid characteristics Consequently semiactive hydraulicmounts have been proposed to use magnetorheological MR fluids as the working fluid The benefit is thatMR fluids can change their rheology upon the application of a magnetic field In this thesis firstly thedesign and modeling of a hydraulic engine mount has been carried out and the simulation of its dynamicbehavior has been done considering the governing equations extracted from the mechanical model of thehydraulic engine mount Finite element analysis using ANSYS has been carried out to calculate parametersof the main rubber of the hydraulic engine mount used in its dynamic behavior simulation Theseparameters include static stiffness volumetric compliance and effective piston area of the main rubber Then design concept and modeling of a magnetorheological MR engine mount has been done From themechanical model of the MR mount its governing equations have been extracted to simulate the dynamicbehavior of the mount Finally to experimentally evaluate the desined hydraulic and MR engine mountsand their effectiveness a prototype mount was built and tested The results of the simulations and testsshow the effectiveness of the designed hydraulic and MR engine mounts in vibration isolation and reducingtransmissibility at resonant frequency Keywords Vibration isolation Hydraulic engine mount Semiactive engine mount Magnetorheological MR fluid Magnetorheological MR engine mount

فيضي، تقي

شبيه سازي، ساخت و تست يك نمونه دسته موتور سيالاتي

جداسازي ارتعاشي , دسته موتور هيدروليكي , دسته موتور شبه فعال , سيال مگنتو رئولوزيكال