The Main Stress dialog box establishes the scale factor for the main stress with respect to the average internal node width.
The main stress in each node will typically have different directions. Therefore, it is not represented through Isolines (lines of equal stress on the deformed structure) or Isoareas (areas of equal stress on the deformed structure). Every node has two perpendicular lines drawn on them. The red line represents the main stress 1, and the cyan-colored line represents the main stress 2. The length of the lines is dependent upon the size of the main stress. The result block contains the scale factor. The arrows at the end of each line are oriented either “in” (compression stress) or “out” (extension stress).