Low-order modeling of vehicle impacts upon boulders embedded in cohesionless soil

In this paper, a planar low-order model is presented for a vehicle impact upon a boulder embedded in cohesionless soil to examine the feasibility of using boulders as anti-ram barriers. The colliding vehicle is represented as a lumped-parameter Maxwell model, the boulder is treated as a rigid body with non-negligible mass, and the soil is represented as a system of lumped-parameter Kelvin models. The low-order model allows for the linear translation of the vehicle and boulder, along with rotational motion of the boulder. The model is validated against two full scale crash tests. Both tests were performed according to ASTM F2656-07 at an M30 rating using a 6800 kg (15,000 lb.) medium-duty sized truck. The low-order model is shown to be descriptive enough for impacts that result in small boulder motion to use in sizing of boulders for use as vehicular barriers.