Design of an independent vehicle suspension guide using the topological optimization method

Abstract

Reducing the mass of automobile aggregates is an urgent task: fuel consumption and emissions to the atmosphere are reduced, material intensity, energy intensity, production costs are reduced, the ratio of the mass of the cargo to the curb weight of the vehicle is increased, etc. The solution of such a problem by the method of topological optimization makes it possible to obtain strong and rigid constructions of minimum mass. The article considers an example of reducing the mass of the chassis of vehicle by synthesizing the power scheme of double wishbones of an independent suspension of an all-wheel drive 4x4 automobile by topological optimization. The peculiarity of the design scheme is the use of a complex finite-element suspension model that allows the synthesis of the power circuit of the upper and lower arms simultaneously and the loading of the suspension is carried out as part of a common beam-rod independent suspension model and with a wheel. The power circuit of the upper arm obtained as a result of solving the optimization problem is a flat construction in the form of the letter A, which is explained by: 1) the absence of forces acting outside the plane of the upper arm of the suspension; 2) a small distance between the hinges of attaching the arm to the body. The power circuit of the lower arm of the suspension also has the shape of an isosceles triangle in plan, however one branch of the triangle has a large construction height in a direction perpendicular to the plane of the arm, which is explained by the high force created by the elastic suspension element resting in this zone on the lower arm. In the absence of forces emerging from the plane of the suspension arm, the task of synthesizing the power circuit is reduced to a flat problem and provides uniquely interpreted power circuits that are easy to implement in the construction of arms. When forces acting perpendicular to the plane of the arm, for example, in the zone of support of the spring-damping suspension element, are applied, it is necessary to increase the construction height of the arm in the zone of action of this force. The overall assessment of the weight of the resulting lever structures in comparison with existing analogs shows a reduction in the weight of the arms by up to 30%.