Optimal Design Of Automobile Suspension Control Arm Based On Strength Loadcse

As an important part of automobile chassis,the design of automobile suspension not only affects the drivability of automobile,but also relates to the driving safety of automobile.The suspension control arm bears a large load when the vehicle crosses obstacles,and may bend due to insufficient design strength.In the meantime,due to the requirements of environmental protection and economy,the control arm needs to be designed with lightweight.This paper studies the optimal design of the control arm based on the strength loadcase.Firstly,perform a linear strength analysis on the control arm.Based on the vehicle design parameters,a multi-body dynamics model of the front Mc Pherson suspension was established in ADAMS.The load at the tire junction was input according to the definition of general strength loadcase,and the dynamic simulation was performed to obtain the load at the joint point of the control arm in each strength loadcase.The linear strength of the control arm was analyzed by the inertia release method,and the Mises stress was used to evaluate the strength of the control arm.In addition,a simulation model of vehicle obstacle crossing is established.According to the physical structure of the tire,a radial tire model with detailed lay-up characteristics is established.The unit type,material model and contact definition,etc.of tire modeling are introduced,and the tire stiffness is verified by simulation and experiment.Establish a complete vehicle model including front and rear suspension,body and powertrain.Considering that the vehicle’s obstacle crossing loadcase is a dynamic impact loadcase,the LS-DYNA explicit calculation method is used to simulate the vehicle shoulder impact loadcase at speeds of 20km/h and 35km/h.By comparing the simulation values of vertical and longitudinal acceleration of wheels with the test values,the validity of the simulation of the vehicle’s obstacle crossing loadcase is verified.Finally,based on the general strength loadcase of suspension and the vehicle obstacle crossing loadcase,the suspension control arm is optimized in topology and size.The maximum stress of the optimized control arm under general strength loadcase is less than the yield limit of the material.When the maximum stress exceeds the yield limit,a certain plastic deformation occurs in the vehicle obstacle crossing loadcase.However,the maximum plastic strain and plastic deformation of the control arm are controlled within a certain range,which ensures that the control arm has a certain load-bearing capacity for this loadcase.Meanwhile,the optimized control arm meets the fatigue durability design requirements,and eventually achieves the lightweight design of the suspension control arm.