LO C\l C\l P ASA DE A PUBLIC LIBRARY REFERENCE AU G .2 4 Z f-i NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS TECHNICAL NOTE 2425 PLASTI C STRESS-STRAIN RELATIONS FOR 75S-T6 ALUMINUM ALLOY SUBJECTED TO BIAXIAL TENSILE STRESSES By Joseph Marin, B. H. Ulrich, and W. P. Hughes The Pennsylvania State C allege <:::-------., NACA Washington August 1951