Research On Vibration Isolation Performance Of Powertrain Mounting System Based On OPAX Method

Vibration is an important factor that affects vehicle ride comfort.The vibration generated by the powertrain is transmitted to the frame,body and other components through the mounting system and finally into the vehicle,so the research on the vibration isolation performance of the mounting system is very necessary.At present,the vibration isolation performance of the mounting system is mostly evaluated by the vibration isolation rate.Furthermore,the mounting is optimized,ignoring the problem of internal vibration.Aiming at a certain SUV,this paper uses a combination of vibration isolation rate and transfer path analysis to comprehensively explain the impact of vibration isolation performance on the interior vehicle.Taking a certain SUV as the research object,using the LMS data acquisition equipment and supporting software to perform vibration testing.The vibration acceleration signal data in three directions of the active and passive ends of the mounting and the target point were measured,analyze the impact of vibration on the target point in the vehicle,and calculate and analyze the generalized vibration isolation rate according to the vibration isolation mechanism of the mounting system.The result shows that the cause of the vibration effect in the vehicle is not the mounting itself,and transfer path is required The path method is further studied.The vehicle interior vibration transfer path model is established,and the vehicle interior vibration test experiment is carried out,and the vibration acceleration signal data of the input end,the target point and the indicator point of the idling and acceleration conditions and FRF are measured respectively.Perform frequency spectrum and order analysis on the data of the two working conditions,analyze that the vibration in the vehicle is mainly caused by the second-order vibration,and analyze the frequency range and the speed range of the target point where the vibration is concentrated.Parametric load identification is carried out using the data of idling conditions and the order slice data of acceleration conditions.The contribution of each path is analyzed on the target point in combination with the obtained frequency response function,and the contribution vector relationship diagram is combined to identify the trigger.The main source of vibration in all directions of the target point.The results of the transfer path method are combined with the vibration isolation rate to comprehensively explain its vibration isolation performance.The results prove that when studying the impact of the vibration isolation performance of the mounting system on the vehicle interior vibration,the vibration isolation performance of the mounting itself is important,but the evaluation method that only considers the mounting system vibration isolation rate is not comprehensive,and the factors of the entire transfer path should be considered comprehensively.The method of using the transfer path to identify the vibration source combined with the vibration isolation rate to determine the source of the problem is more accurate,and provides a good idea for subsequent further optimization.