The paper presents a solution to the buckling under shear stress of infinitely long plates orthogonally reinforced by stiffeners having both flexural and torsional rigidity. Each family of stiffeners is assumed to consist of equally spaced identical stiffeners. Numerical results are given for the case of a plate with transverse stiffeners and a central longitudinal stiffener for the following three cases:
(i) Transverse and longitudinal stiffeners of closed tubular cross-section.
(ii) Transverse stiffeners of closed tubular cross-section, longitudinal stiffeners possessing only flexural rigidity.
(iii) Transverse stiffeners possessing only flexural rigidity, the longitudinal stiffeners being of closed tubular cross-section.
Relationships between the buckling stress parameter K and the flexural rigidity parameter γ of the stiffeners are presented for each of the three cases when the identical transverse stiffeners are placed at spacings of d, 0·8d and 0·5d, where d is the depth of the webplate.
Case (i) has provided values of the buckling coefficient K for finite rectangular plates clamped on three edges and simply-supported on the remaining edge.