The Number of Treads can be set to 4 or 5. The tread widths and relative pressure (stress) magnitude of each can be specified, but 1/4-symmetry is required for the nonuniform contact stress patch. The slider bar(s) is/are used to specify the relative pressure magnitude between the different treads. Note that the peak pressure is always defined by the Peak Pressure (kPa) in the Load Parameters section. The stress distribution along the length of the tire can be selected as Constant, Parabolic, or Half Sine Wave. All of these selections affect the length of the tire contact patch in the x-direction, which is calculated by EverStressFE to produce the specified wheel load for the peak pressure and pressure distribution. Changes made to these parameters are immediately reflected in the Tread Modeling Designer bar graph as well as the main graphics panel. The user may save a User Defined load in the form of a .node file by clicking the Save Custom Load button. This can then be re-loaded later by choosing the Load Custom option for Tire Contact. An an example of the Tread Modeling Designer is shown in Figure 1 below. The corresponding Contact Pressures views are shown in Figure 2 and Figure 3 below for the 3D Perspective and Plan View perspective, respectively. Contact Pressures are plotted with a freely distributable version of DPlot Jr (http://www.dplot.com/other.htm#junior) that is packaged with EverStressFE.
