Realtime Measurements of the Relation Between the Acting Force, Unsprung and Sprung Masses on a Road Simulator Test Stand for Large-Size Vehicles

Abstract

The article presents the results of measurements obtained during durability tests of large-size vehicles. During the durability tests, the correlation between the acceleration obtained under the semi-trailer wheel, on the axis and on the suspension of the bracket and at the place of attachment of the pneumatic suspension cushion was checked. Measurements were carried out using single-axle induction accelerators. The tests were carried out for an unloaded and fully loaded semi-trailer with a load of 26 tons. For analysis of the results, in each test three road profiles controlling the operation of pneumatic actuators were generated at the MTS durability stand. The statistical and Auto Spectrum Density (ASD) frequency analysis were carried out. The presented results indicate 10 times greater accelerations registered under the semi-trailer wheel on the unsprung actuator plate. Acceleration obtained on the axis accounts for 30–65% of the acceleration value registered under the semi-trailer wheel. Basic frequencies for the semi -trailer axis and other suspension elements have been determined. As a result of the frequency analysis in the range up to 50 Hz, no frequencies characteristic of the plate under the semi-trailer wheel were found. The obtained results will be used to build an analytical model of the semi -trailer suspension specifying the damping coefficients for its individual elements.