Figure 13.
Stiffness degradation in sample SW: (a) F-15; (b) F-30; (c) F-45; (d) F-60; (e) F-75. Three types of perforations were analyzed (2/6 mm, 4/4 mm, or 6/2 mm).
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.