ON THE ROLE OF MEAN MAXIMUM PRESSURE AS AN INDICATOR OF CROSS-COUNTRYMOBILITY FOR TRACKED VEHICLES

The role of mean maximum pressure (MMP) as an indicator of cross-count ry mobility is reviewed. The values of MMP under a tracked vehicle are predicted using an empirical formula proposed by Rowland and a comput er-aided method, known as NTVPM-86. It is shown that values predicted using NTVPM-86 are in closer agreement with measured data than those p redicted using Rowland's formula. The variations of MMP with vehicle w eight, track width, number and diameter of roadwheels are predicted us ing both methods over a clayey soil, snow and muskeg. It is found that in most cases, there is a significant difference in the values of MMP predicted using the two methods. It is also shown that Rowland's meth od takes into account only a limited number of vehicle design paramete rs and that it can only be employed to predict vehicle mobility in a q ualitative manner. On the other hand, NTVPM-86 takes into account all major vehicle design features and terrain characteristics and can be u sed to predict quantitatively vehicle tractive performance over soft t errain. It is hoped that this paper will stimulate vehicle engineers i n the use of advanced computer-aided methods in their practice and tha t it will encourage further research in this vital area.