1 Sep 2020

PUBLICATION NOTICE: Seasonal Effects on Vehicle Mobility: High-Latitude Case Study

Abstract: Seasonality plays a key role in altering the terrain of many military operating environments. Since seasonality has such a large impact on the terrain, it needs to be properly accounted for in vehicle dynamics models. This work outlines a variety of static and dynamic seasonal terrain conditions and their impacts on vehicle mobility in an austere region of Europe. Overall the vehicles performed the best in the dry season condition. The thaw season condition had the most drastic impact on mobility with all but the heavy tracked vehicle being almost completely NOGO in the region. Overall, the heavy tracked vehicle had the best performance in all terrain conditions. These results highlight the importance of incorporating seasonal impacts on terrain into NRMM or any vehicle dynamics model. Future work will focus on collecting more data to improve the empirical relationships between vehicles and seasonal terrain conditions, thereby allowing for more accurate speed predictions.

29 Apr 2020

PUBLICATION NOTICE: Preliminary Assessment of Landform Soil Strength on Glaciated Terrain in New Hampshire

Abstract: Accurate terrain characterization is important for predicting off-road vehicle mobility. Soil strength is a significant terrain characteristic affecting vehicle mobility. Collecting soil strength measurements is laborious, making in-situ observations sparse. Research has focused on providing soil strength estimates using remote sensing techniques that can provide large spatial and temporal estimates, but the results are often inaccurate. Past attempts have quantified the soil properties of arid environments using landform assessments; yet many military operating environments occupy high latitude regions with landscapes dominated by glacial deposits. This study took preliminary strength measurements for glacial landforms deposited from the Laurentide Ice Sheet in New England. A range of common glacial landforms were sampled to assess shear strength, bearing capacity, and volumetric moisture content. Glacial outwash landforms had the highest average shear strengths, glacial deltas the lowest. There was a significant negative correlation between silt content and shear strength of the soil, a significant positive correlation between bearing capacity and clay content, and a significant negative correlation with sand content. Moisture content of soils was inversely correlated to the abundance of gravel in the deposit. This work provides initial insight to this approach on glaciated terrain, but continued sampling will provide more robust correlations.