The elastic buckling stress for thin flat plate of length L, depth d and thickness t simply supported along four edges and loaded by bending stress distribution is given by

• A. fcr = π2E/k[12(1-μ2)(d/t)2].
• B. fcr = π2E/k[12(1+μ2)(d/t)2].
• C. fcr = kπ2E/[12(1+μ2)(d/t)2].
• D. fcr = kπ2E/[12(1-μ2)(d/t)2].