Investigation of Heavy Vehicle Dynamics Behaviour Under the Wind and Bridge Motion Excitations

Abstract

The floating bridge solution at Bjørnafjorden on the soon-to-be upgraded E39, pushes the envelope of engineering development. The route will be used extensively to transport commercial goods, in addition to personal commute. The vehicular traffic on this bridge will be exposed to gusty wind and oceanic currents of a 1-year storm condition. This induces stochastic motion to the bridge. This master thesis investigates the dynamic behavior of a tractor-semitrailer vehicle on the Bjørnafjorden bridge, exposed to such conditions. The driver-vehicle-bridge system is developed on MSC.ADAMS Car/Truck, which runs on a co-simulation with MATLAB/Simulink as master. A method to simultaneously induce wind gusts and motion of the bridge is established. Bridge motion is induced as displacements, via x-Post test rig on MSC.ADAMS. Crosswinds dynamically excite the tractor-semitrailer units through computed forces and moments. ADAMS PID control, which is an advanced steering controller compared to the Snider driver model, is used to steer the vehicle to maintain the desired path. The tractor-semitrailer is be evaluated for stability in crosswind and moving ground conditions at different test speeds. Based on vehicle dynamic responses, lane violation, risk of roll-over, driver steering effort and lateral sideslip limits are assessed for the laden and unladen vehicle on road surfaces of friction µ = 0.7 and µ = 0.3. Operating speed limits for the tractor semitrailer on the Bjørnafjorden floating bridge is suggested to the Norwegian Public Road Administration under the influence of 1-year storm conditions.