Effects of braking conditions on the dynamic responses of multi-axle heavy-duty vehicles coupled with pavement roughness and flexibility

Multi-axle heavy-duty vehicles (MHVs) are essential for military equipment transport due to their safety and stability. However, braking dynamic responses between MHVs and pavement systems still remain underexplored, particularly regarding their complex load transfer mechanisms. This paper develops an enhanced model of a multi-axle heavy-duty vehicle (MHV) coupled with the uneven and flexible pavement. An advanced coupling iterative method is proposed to solve the highly dimensional equations of the MHV-pavement coupled system. The proposed method was validated through experimental tests, with characteristic parameters of vertical accelerations showing relative errors between 0.42% and 11.80%. The coupling effect and influence mechanism of the braking process are investigated by characteristic parameters of the dynamic responses. Additionally, the influences of braking conditions and pavement parameters are analyzed in time and frequency domains in order to reveal the vibration mechanisms of the coupled system. Moreover, this study establishes a theoretical foundation for monitoring pavement health via vehicle-mounted acceleration signals, which is necessary in military transportation.