This is an experimental study of the interaction between dynamic axle load of heavy vehicles and pavement roughness. The pavement roughness statistics were calculated on the basis of the pavement roughness profile measured in the left and the right wheel paths at 6-inch intervals. They were calculated at 50-meter intervals, using the elevation of the right wheel path as well as the average elevation of the right and left wheel paths. The exponential relationships fitted to the Root Mean Square of the dynamic axle - load demonstrated the differences in the dynamic behaviour of the rubber and the air suspension.
Vehicle Pavement Interaction
Previous studies for dynamic response of pavement
In 1943, Burmister developed a closed-form solution for a two-layered, linearly elastic, half-space problem, which was later extended to a three-layer system. Since then, and with advances in computer technology, the theory has been extended to deal with multilayer systems. Two-Dimensional (2-D) FE models (axisymmetric or plain strain models) were the first successful examples of the application of the FE method in pavement analysis. The axisymmetric modeling approach assumes that the pavement system has constant material and geometric properties in horizontal planes, and the traffic loading is circular load applied on the pavement surface (Bonaquist 2005).
With the advance of fast computers and algorithmic improvements, the use of 3-D FE analysis has become widespread in pavement structural analysis. In comparison to the relatively simple layered elastic theory or 2-D axisymmetric model, the 3-D FE model can consider many analysis scenarios, such as non-uniform tire-pavement contact stress, irregular tire imprint area, discontinuities in pavement (cracks or joints), viscoelastic and nonlinear material properties, infinite foundation, material damping, quasi-static or dynamic analysis, crack propagation, coupled temperature effect, bonded or de-bonded interface, and so forth.
Generically tyre loads vary in two ways. These are the variation of load between vehicles travelling on a pavement, and the varying loads applied by a vehicle along the pavement. The first type of variation is accommodated in pavement analysis through equivalent load concepts. The second type of variation is caused by the pavement roughness-induced movement of the vehicle. This is traditionally termed dynamic pavement loading (Ehsan 1993). The use of the term dynamic loading in pavement analysis refers to a load with a constant magnitude that is moving along a pavement or a load that is varying in load magnitude. The following four definitions should clarify the terminology.
The load magnitude of a Static Load is independent of time and position, and the position where it is applied is independent of time. For a Moving Constant Load the load magnitude is constant but the position where it is applied is dependent on time. For a Dynamic Load the load magnitude is dependent on time but not on position, and the position where it is applied is independent of time. The load magnitude of a Moving Dynamic Load is dependent on both time and position and the position where it is applied is also dependent on time (Choubane ...