Development of an Independent Front Suspension for Truck Tractors

Design and experimental validation stages of an independent front suspension (IFS) that is designed for truck tractors of articulated commercial vehicles are summarised. Firstly, the suspension geometry, which satisfies the required conditions of minimum deviation of camber angle and track width during wheel travel, is obtained within the given design volume by using Multibody Systems (MBS) and Design of Experiments (DOE) approaches. Subsequently, the kinetic analysis is carried out for the suspension system and the critical design loads that may act on the structural elements are determined. Taking these loads into account, the mechanical design of the suspension system elements is performed. The Finite Element Analysis (FEA) is applied to the complete suspension system for the chosen critical load conditions. Stress concentrated regions on the crucial system elements are determined and improvements are indicated, which result in the reduction of stress concentrations. In the last part of the study, prototyping and fatigue tests are carried out. Throughout bench tests, in which real service conditions are simulated, no failure of any sort is encountered. The final suspension system (pair) is 31% lighter than an equivalent rigid front axle in terms of load capacity.