The Performance Analysis And Optimization Research Of A Vehicle Suspension Control ARM

Environment pollution and energy shortage are two severe problems in automobile industry.And lightweight design can improve this situation effectively.The research on automobile lightweight has always been a hot topic,and also a long-term challenge in automobile industry.As a critical part of vehicle suspension system,the suspension control arm plays the role of transmission and guidance.The lightweight design of control arm must satisfy design requirements,including strength,stiffness and natural frequency and so on.Therefore,the performance analysis and optimization of the suspension control arm are particularly important.Taking the control arm of a vehicle with MacPherson suspension as an objective,the multi-body dynamics model is built with the vehicle information by using Adams.Loads at the contact patch are calculated under a series of load cases,and are used as input data for multi-body dynamics simulation to obtain the loads on the control arm.The loads obtained on the control arm will be employed in the performance analysis and later optimization.To obtain the performance,the FEA model of the control arm is established to analysis the stiffness,strength and natural frequency,in which the material parameters is obtained from uniaxial tensile tests.And stiffness and strength tests are conducted to verify the FEA results by using the fixture designed.The fatigue test is conducted too.The results of FEA and tests show that,the FEA model is built rightly,and the performance of the control arm can meet all the design requirements.To meet the lightweight design of the new energy vehicle,topology optimization is employed to redesign the control arm.Considering the stiffness and natural frequency performances,it is a multi-objective topology optimization for the control arm under a series of complex load cases.With average frequency method and grey relational analysis,the comprehensive mathematical model of this optimization is established by compromise programming method.According to the comprehensive mathematical model,the different weight coefficient distribution resulted in optimization results is analyzed and decided.And the influence of the draft constraints on the optimization results is compared and analyzed.Finally,the control arm is lightweight redesigned by selecting the optimization result with two-way draft constraint.And the performance of the new control arm is analyzed.The results show that the new control arm can meet all the design requirements.And the mass is reduced by 13% in comparison with the previous one,which is remarkable.