AS ISO 16754:2021 Earth-moving machinery – Determination of average ground contact pressure for crawler machines

AS ISO 16754:2021 Earth-moving machinery – Determination of average ground contact pressure for crawler machines.
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ISO 16754 was prepared by Technical Committee ISO/TC 127, Earth-moving machinery, Subcommittee SC 1, Test methods relating to machine performance.
4 Requirements
4.1 General
The machine shall be the standard configuration as specified by the manufacturer.
4.2 Calculation of average ground contact pressure, P
Determine the average ground contact pressure, Pg, in kilopascals, using Equation (1):
where
in is the operating mass;
n is the number of tracks;
L2 is the crawler base;
L6 is the overall crawler length;
W4 is the track shoe width.
NOTE 1 Equation (1) provides allowance for some track penetration into the supporting soil surtace and the resulting increase in support area.
NOTE 2 In the Equation (1). symbols with subscripts have been used to represent the dimensions in order to avoid confusion between codes (e.g. L6) and values.
4.3 Determination of L6
L6 can also be determined using Equation (2). which can be used for all types of crawler configurations, including that shown in Figure 4. provided that the angle, a, is greater than or equal to 100.
where
d is the distance on the Z coordinate between the ground reference plane and the Z plane (see ISO 6746-1) passing through the front and rear roller axis, as shown in Figure 4
L2 is the crawler base;
L6 is the overall crawler length.
NOTE In the equation, symbols with subscripts have been used to represent the dimensions in order to avoid confusion between (e.g. L6) codes and values.AS ISO 16754 pdf download.