Simulation And Optimization Of A Car's Ride Comfort Considering The Flexibility Of The Subframe

As the car is widely used,its importance has become apparent.Today's people use the car as a means of transportation is not only limited to short-distance use,but also have the ability to travel comfortably in the middle and long distances.It is also more urgent to ensure good ride comfort when driving the car.In the past,major car manufacturers need to spend a lot of manpower and material resources on the development and testing of car ride comfort performance.However,with the improvement of virtual simulation technology and the continuous development of various types of simulation software,many car companies will pass through before the design of physical vehicles.Virtual modeling to simulate the situation of the vehicle in different working conditions and road conditions.Based on this,the vehicle ride comfort simulation software can be used to simulate the ride comfort of the vehicle.In this paper,we have consulted relevant data and found that the elastic deformation of the flexible body itself will affect the movement of the machine to a certain extent.Taking into account the fact that having an elastic part as a rigid body will affect the actual results,a rigid-flexible coupling model of the entire vehicle is created based on relevant theory,and carried out research on its ride comfort.First of all,this paper studies a certain type of passenger cars,and creates subsystem models such as front and rear suspension models,steering models,tire models,and powertrain models through the MSC.ADAMS/Car software.These models are also used in ADAMS/Car.A rigid-flexible coupling model of the completed vehicle was established,in which the rear suspension subframe was built using a flexible body method.First,in the CATIA 3D modeling software,a 3D solid subframe model was established based on the relevant parameters of the subframe,and then it was imported into the HyperMesh finite element software to create its finite element model,and the subframe finite element model was performed modal analysis,and export modal neutral file(.mnf),and then imported into the original rear suspension model,replacing the original rigid subframe.By assembling the various subsystems and the rigid-flexible coupled rear suspension,a rigid-flexible coupled vehicle model can be obtained.Then,according to the relevant laws and regulations,some evaluation indexes of ride comfort were proposed,and the evaluation criteria of ride comfort under different road surfaces were determined.Then the suspension simulation and comparison of rigid rear suspension and rigid-flexible coupled suspension were performed.Suspension kinematics and elastic dynamics of the flexible subframe are available.Then,a random asphalt road surface was established in the pavement contourer,and then a pulsed bump road surface was established.The ride comfort of the rigid vehicle and the rigid-flexible coupling vehicle model was compared and the driving conditions at different road surfaces were obtained.The acceleration time history and power spectrum at the driver's seat were calculated and the root mean square value of the weighted acceleration was calculated,and the ride comfort of the vehicle was analyzed.Finally,by changing the stiffness and damping of the suspension and vehicle parameters such as wheel tire stiffness,the effects of their changes on the ride comfort of the vehicle are studied.By the approximate D-optimal method in the test design method,the stiffness and damping of the suspension are optimized to find a better match so as to achieve the goal of reducing the root mean square value of the vibration acceleration of the driver.The simulation results of random road and pulse road show that the RMS value of the optimized weighted acceleration at the driver's seat has been reduced to some extent,and the ride comfort of the vehicle has been improved.