c=1/Sqrt[2]
q={0,-400.}

G={{-c,-1},{c,0}}
MatrixForm[G]
IG=Inverse[G]


s=-IG.q
Astresslimit=s/24
Abucklinglimit=Sqrt[400.*4*100^2/(Pi*21000)]
NMinimize[{A1/c+A2{A1≥23.57023,A2≥16.6667}},{A1,A2}]
NMinimize[{A1/c+A2{A1≥23.57023,A2≥15.5731}},{A1,A2}]