Buckling load factor (eigenvalue), lambda, from the simple closed form PANDA-type model retained as one of the many buckling models included in PANDA2

This is Equation No. 57 from the 1987 PANDA paper, "Theoretical Basis of the PANDA Computer Program for Preliminary Design of Stiffened Panels Under Combined In-Plane Loads", by David Bushnell, Computers & Structures Vol. 27, No. 4, pp. 541-563, 1987.

The various quantities on the right-hand side of the equation are defined in the 1987 PANDA paper, which can be downloaded from this website.

This is the so-called "PANDA-type" (closed form) buckling model, which is frequently referred to as "PANDA-type model" in the PANDA2 literature.

Page 76 / 227