Dynamic Interaction Between Heavy Vehicles And Speed Bumps

The paper presents finite element (FE) model development and experimental validation for a truck tractor with a three axle single drop lowboy trailer. The main objective of this research activity was to create a simplified, three dimensional virtual FE model, applicable for computer simulation of dynamic interaction between a vehicle and a bridge or road structure. Such model should provide a reliable approximation of dynamic loadings exerted by the wheels to the bridge or pavement structure for a wide range of total weights and speeds considered. To meet this requirement the FE model should have correct mass distribution and properly represented stiffness characteristics of the suspension system. As explicit laboratory testing of the suspension system requires its disassembling and is very expensive, an indirect method was applied to find the stiffness and damping characteristics of the suspension. The study reported in this paper consists of experimental and numerical parts. During the experimental tests the vehicle was driven across the speed bumps at different speeds. The relative displacement and acceleration histories were recorded for several points located on the vehicle axles and the frame. In addition, a speed bump was scanned on site using a laser scanner. The experimental data was subsequently used for the development and calibration of the spring and damping characteristics for suspension systems of the FE model. The numerical part was based on non-linear, explicit, dynamic, finite element (FE) analysis using the LS-DYNA computer code.