Design & analysis of 2 point aluminum upper control arm in modular multi link rear suspension system
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
In current automobile market, due to the need of meeting future CO2 limits and emission standards, demand for hybrid systems is on the rise. In general, the requirements of modern automobile architecture demands modular chassis structure to develop vehicle variants using minimum platforms. The multi-link modular suspension system provides ideal solution to achieve these targets. To match ideal stiffness characteristics of system with minimum weight, aluminum links are proving a good alternative to conventional steel forged or stamped linkages. Design of current 2-point link (Upper Control Arm) is based on elasto-kinematic model developed using standard load cases from multi body dynamics. CAD system used is CATIA V5 to design upper control arm for rear suspension. This arm connects steering knuckle & rear sub frame. For Finite Element Analysis we used Hyperworks CAE tool to analyze design under all load cased & further optimization is done to resolve highly stressed zones. An optimized solution presented with a balance of ideal stiffness & strength. A CAD model developed with aluminum forged alloy (6082 - T6) is compared with steel & other aluminum alloys for strength & stiffness characteristics. The present FEM based results showing a good agreement with experimental validation of complete prototype system, when tested on dynamic test bench. We manufactured this prototype using machining process out of rolled aluminum block. For further volume production, same design can be made using forging process also. The aluminum control arms meet the required stiffness & strength targets with significant reduction of weight up to 20%. Using such optimized lightweight parts will reduce dependency on heavier steel material in coming future. It provides new insight towards development of chassis structural parts using aluminum Alloy with good confidence level.