Robustness to sand dune impact is one of the key requirements for Jaguar Land Rover products. Historically off road vehicles were built on a ladder sub frame; and the steel cross beam at the front provided robust protection for the cooling pack. With the move to monocoque construction, the cooling pack became vulnerable to low speed grounding damage. Unfortunately this vulnerability is not confirmed until later in the program when fully representative vehicles are available, which results in late engineering changes that are expensive, time consuming and stressful. Like all late changes it is rarely optimised for cost and weight. With no historic literature or procedure available, the challenge was to model the physics of sand media and also solve the complex multi-physics problem of impact of the whole vehicle with the sand dune. This paper discusses various challenges faced while developing a state-of-the-art modelling method for sand media and a full vehicle impact with the sand dune. Our first challenge in modelling sand was to get accurate material properties for which rigorous testing was done in the lab. We also benchmarked various methods in structural dynamics CAE tool LS-Dyna including Arbitrary Lagrangian Eulerian (ALE), Discrete Element Solid (DES), Solid Finite Element Method (Solid FEM), and Smoothed Particle Hydrodynamics (SPH). This paper further discusses the merits of these methods and the best method to solve the complex multi-physics problem of a full vehicle impact with the sand dune.
