Reinforced Structure rules in BMM page 117, TO AUE page 155.
While hardened armor effectively require 40 points of damage (20 full armor circles) to cause PSR, it is unclear if this applies to Reinforced Structure. Its function is similar to the hardened armor though its rules wording is not identical. BMM clarifier entry on page 114 only explicitly notes special armors increasing the threshold for PSRs.
So how does RIS interact with PSRs? Only full circles count as damage for PSRs or does it merely virtually double internal structure circles?