| Owing to relaxations in weights and dimensional policies on freight vehicles, the population of heavier and longer articulated vehicles, often referred to as Long Combination Vehicles (LCVs), has steadily increased in North America. The directional stability and control limits of most combinations have been adversely affected by the increase in weights and dimensions, which has prompted many concerns related to operational safety of such vehicles. Particularly, A-train doubles, which belong to the classification of LCVs, exhibit larger magnitude oscillations in both lateral and yaw motions under directional maneuvers, which limit their directional dynamic performance at highway speeds. Two concepts in damped articulations are formulated and their potential benefits or limitations in enhancing the dynamic behavior of A-train doubles are investigated in terms of different performance measures, which are evaluated under both open and closed-loop maneuvers. These concepts are based upon articulation dampers introduced between the first semitrailer (unit 2) and the A-dolly (unit 3), referred to as Case I, and between the first and second semitrailer (units 2 and 4), referred to as Case II. (Abstract shortened by UMI.)... |
