Proposal of Structural Validation Criteria for Numerical Simulation and Bench Test of a Semi-trailer Suspension Parts

This paper presents the development of a validation criteria method for designing of spring brackets, wear pads and equalizers of a leaf spring suspension of a semi-trailer from the perspective of durability and peak loads. The method consisted of the application of a finite element model from strain data collected in the application test. The results obtained in the components during the trailer’s operation were converted into load through calibration curves. The stress-life method was adopted, correcting the mean stress by the Goodman criterion and with the calculation of accumulated damage using Palmgren-Miner with cycle counting by rainflow in the structures during the data acquisition path. The relation between damage accumulation and the life expectancy of the components, defined in a specific distance (mileage) was established. Basquin´s equation was also used. The static equivalent load approach was used, where the equivalent stress was converted into load and normalized by the technical load of the studied suspension (11 tons per axle). This procedure was repeated for the three load cases of the suspension: vertical, lateral and longitudinal. As a result, a table of boundary conditions, where fatigue and peak loads are specified as a function of the technical load, was proposed. Additionally, another contribution of this study was the proposal for loading blocks to evaluate the components, allowing the obtained results to be used to validate other similar suspensions under similar operating conditions.