Shock Loading Experiments and Requirements for Electric Wheel Motors on Military Vehicles

The University of Texas at Austin Center for Electromechanics (UT-CEM) has conducted a set of simulations and full-scale experiments to determine suitable shock load design requirements for in-hub (wheel) propulsion motors for hybrid and all-electric combat vehicles. The characterization of these design parameters is required due to recent advancements in suspension technology that have made it feasible to greatly increase the tempo of battle. These suspension technologies allow vehicles to traverse off-road terrains with large rms values at greater speeds. As a result, design improvements for survivability of in-hub motors must be considered. Defining the design requirements for the improved survivability of in-hub motors is the driving factor for this research.

Both modeling and experimental results demonstrate several realistic scenarios in which wheel hubs experience accelerations greater than 100g, sometimes at very low vehicle speeds. This paper focuses on the experimental determination of suitable design goals for in-hub motors (wheel motors), describing the experimental test rig, experiment procedures, and experimental results from testing conducted at UT-CEM. The paper also discusses implications of these results on wheel motor design, leading to the conclusion that a realizable and feasible design goal for a combat vehicle wheel motor shock rating is 150 g's, with a 10 to 20 ms pulse width.