(NASA-Til-64497) NONLIIYEAG At411 TAblGEYT 183- 1567 1 STIPPNESS OF ltlPEBFECP BEAK COLUMNS (NASA) 28 p HC A03/MF A01 CSCL 20K Unclas G3/3Y 02382 NONLINEAR AND TANGENT STIFFNESS OF IMPERFECT BEAM COLUMNS Melvin S. Anderson DECEMBER 1982 Nat~onal Aeronautics and Space Adrn~nlstrat~on