Dynamic road load simulation of transportable cranes

This paper develops a general tool for understanding the dynamic road loads generated by mobile cranes that use a boom support dolly. The focal point is the dynamic road loads generated by the vehicle, which is a primary cause of pavement damage. A pitch plane model of the crane is developed and a finite element model is used to characterize the flexible motion of the boom. The simulation can characterize both the traditional and modern styles of mobile cranes. The traditional style uses a walking beam suspension on the carrier and a leaf spring suspension on the dolly. The modern cranes implement a hydropneumatic carrier suspension and an air ride suspension on the dolly. Additionally, other suspension configurations are implemented. The simulation results show that modern cranes generate significantly lower dynamic loads than do traditional cranes. This indicates that there is a need to regulate axle load limits in a manner that compensates for different suspension systems.