Optimal Design Of Balanced Suspension Structure Based On A Heavy Vehicle

With the social development of China, vehicles’ comfort and passability,especially for heavy trucks, have become increasingly demanded. While meeting therequirements of improving transport efficiency, leaf spring balanced suspension inheavy truck can ensure the vehicles’ riding comfort and handling stability. Becauseof its low cost, simple structure and easy maintenance, leaf spring is widely used inbalanced suspension. Balanced suspension system’s structural safety has a directimpact on the entire vehicle’s safety. In this paper, we take a heavy truck as theplatform, use the finite element analysis for balance-axle brackets and leaf spring,and carry the structural optimization design.First of all, the force analysis of the leaf spring balanced suspension was carriedout, using the mechanical analysis method of whole-part-whole. In order to analyzethe actual force conditions of the balance-axle brackets and the leaf spring, the forcediagram of the balanced suspension was established with the balanced suspension asthe research object. Through the analysis of balance suspension under different loads,such as static equilibrium condition, accelerating condition, steering condition andbending and twisting condition, the force conditions of the balance-axle brackets andthe leaf spring under various operating conditions were determined.Secondly, according to the stress condition of the balance-axle brackets,topology optimization analysis in the application of variable density method wascarried in the Hyperworks Optistruct module, and the optimization results wereanalyzed. According to the result cloud gained in topological optimization, thestructure optimization design was carried, and the optimized3D model ofbalance-axle brackets was set up and analyzed with FEM. The comparison ofstructure properties between the original structure and the optimal one ofbalance-axle brackets was carried. The results of finite element analysis for theimproved balance-axle brackets showed that the weight reduced greatly whilemeeting the using requirements of the structure, and the remarkable improvementeffect in lightweight was achieved.Finally, the structural parameters of leaf spring were optimized. The originalstructure finite element model of taper-leaf spring was set up and analyzed withFEM. The results found that it could not meet the using performance requirementsunder full load condition. The mathematical model of optimum design for taper-leafspring was introduced, and the structure parameters were optimal designed in the application of Matlab Toolbox, under the decision requirements of balancedsuspension. In order to truly reflect the fabrication of taper-leaf spring, theoptimized solid model of each leaf spring in free status was set up and analyzed withFEM. The structure properties between the original structure of taper-leaf spring andthe optimal one were compared. The results of finite element analysis for theimproved taper-leaf spring showed that, it not only meets the using performancerequirements, but also the working stress is also greatly reduced, and the vehicleriding comfort and handling stability were improved to some extent.