L Euler 1744 column-buckling P_cr=π²EI/L²; modern modern foundational text + Timoshenko + plate / shell + 2024 nonlinear-FEA collapse design.
L Euler 1744 column-buckling P_cr=π²EI/L²; modern modern foundational text + Timoshenko + plate / shell + 2024 nonlinear-FEA collapse design.