Q: Why do we obtain 8 CDRs for each end of beam of a prismatic member?
REV 6.01

A: Why should you "get only 4"? In some cases, the maximum stress is not at the extremes of the section, so we compute stress at 8 points that will normally govern: 4 extreme points, the intersection of the two neutral axes, and the 3 most extreme points on a neutral axis.